THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 PRESENTED BY 
 
 PROF. CHARLES A. KOFOID AND 
 MRS. PRUDENCE W. KOFOID 
 
EXPERIMENTAL INQUIRY 
 
 INTO THE LAWS OF 
 
 ORGANIC AND ANIMAL LIFE. 
 
J. Moir, Printer, West Register Street, Edinburgh. 
 
AIST 
 EXPERIMENTAL INQUIRY 
 
 INTO THE 
 
 LAWS* WHICH REGULATE THE PHENOMENA 
 
 OF 
 
 ORGANIC AND ANIMAL LIFE. 
 
 BY 
 
 GEORGE CALVERT HOLLAND, M. D. 
 
 BACHELOR OF LETTERS OP THE UNIVERSITY OF PABIS ; 
 
 FORMERLY SENIOR PRESIDENT OF THE HUNTERIAV MEDICAL SOCIETY, 
 AND PRESIDENT OF THE ROYAL PHYStOi. SOCIETY s 
 
 OF EDINBURGH, .- ' ' > 
 
 The application of particulars to a whole will often discover their fallacy, 
 ami the applying any general system to particulars will often discover its 
 true limits -CULLEN. 
 
 EDINBURGH : 
 PRINTED FOR MACLACHLAN AND STEWART j 
 
 AND S1MPKIN AND MARSHALL, LONDON. 
 
 1829. 
 
TO 
 
 E. MULLIGAN, M. D., F.R.S.E., &c. 
 JOHN FLETCHER, M. D., &c. 
 
 AKD 
 
 WILLIAM SELLER, M. D., &c. 
 
 MY DEAR SIRS, 
 
 IF friendship, and a sense of gratitude for many favours received, had not 
 naturally directed me to you, as individuals to whom I could, with heartfelt 
 satisfaction, dedicate the present production, your well known intellectual 
 acuteness and professional acquirements would alone have been sufficient to 
 inspire a wish to possess the honour of your names. In having the opportu- 
 nity of uniting the feelings of the friend with the admiration of a pupil, it is 
 with particular pleasure I embrace the present occasion to assure you that I 
 am not insensible of the honour of your friendship, nor ungrateful for the 
 benefits you have conferred, and the interest you have shown in promoting 
 the completion of this Physiological Inquiry. To you I am particularly 
 indebted for having examined the sheets during the progress of their printing. 
 Your liberal remarks have enabled me, in many instances, to take a more 
 extended or correct view of certain of those physiological subjects considered 
 in their outline or detail in the present volume ; and your approbation and 
 encouragement have made me cultivate with pleasure what otherwise might 
 have been a labour. Believe me, 
 
 My DEAR Si as, 
 
 Your Sincere and Faithful Friend, 
 
 G. CALVERT HOLLAND. 
 
 MANCHESTER June 2, 1820. 
 
CONTENTS. 
 
 Page, 
 CHAP. I. 
 
 Animal Heat is not in the direct ratio of the quan- 
 tity of oxygen inhaled, but in the inverse ratio of 
 the quantity of blood exposed to this principle . 1 
 
 CHAP. II. 
 
 The Cause of Animal Heat ........ 34 
 
 CHAP. IIT. 
 
 Secreting surfaces are not dependent on Nervous 
 communication between their own individual parts 
 and the origin of the nerves, nor does Galvanism 
 re-establish or excite their particular functions by 
 maintaining such a relation ..... .68 
 
 CHAP. IV. 
 
 The Distribution of the Blood at different Ages and 
 Seasons ............. ; 98 
 
 CHAP. V. 
 
 Temperature at different Ages ...... 121 
 
 CHAP. VI. 
 
 The manner in which the System is adapted to the 
 influence of Cold 143 
 
Vlll CONTEXTS. 
 
 Page. 
 
 CHAP. VII. 
 
 On the Torpidity of Hibernating Animals ... 161 
 
 CHAP. VIII. 
 
 The means by which the System is enabled to bear 
 a temperature much superior to that of the body 174 
 
 CHAP. IX. 
 
 The Influence of Disease on the production of Heat 189 
 
 CHAP. X. 
 
 The Function of the Eighth Pair of Nerves . . . 208 
 
 CHAP. XI. 
 
 The Influence of Narcotics on the generation of Ani- 
 mal Heat and the Digestive Powers . . . 241 
 
 CHAP. XII. 
 
 The Causes which influence the Action of the Heart 260 
 
 CHAP. XIII. 
 
 On Palpitation 280 
 
 SECT. I. The general causes which produce 
 
 this affection . . . ib. 
 
 SECT. II. Organic causes which produce pal- 
 pitation 286 
 
 CHAP. XIV. 
 
 Syncope ....;. p'V^; r ^^ t t ^QQ 
 
 SECT. I. The manner in which the Sanguife- 
 rous and Nervous Systems are acted upon by 
 those causes which produce Syncope . . , ib. 
 

 CONTENTS. IX 
 
 Page. 
 
 SECT. II. An examination of the causes which 
 occasion Syncope by changing the ordinary 
 course or freedom of the circulation . . . 316 
 
 CHAP. XV. 
 
 Physiology of Passion 324 
 
 SECT. I. The Seat of Passion ib. 
 
 SECT. II. The Phenomena and Physiology of 
 
 Passion 333 
 
 SECT. Ill The Influence and Effects of Pas- 
 sion 350 
 
 CHAP. XVI. 
 
 An Inquiry into the Nature of the Vital Principle , 363 
 SECT. I. An Investigation of the different phe- 
 nomena attributed to an unknown or imma- 
 terial principle ib. 
 
 SECT. II. An Inquiry into the nature of that 
 principle by means of which the System is 
 maintained in health and vigour . . . 381 
 
 CHAP. XVII. 
 On Sympathy 398 
 
 CHAP. XVIII. 
 
 The general Action of Emetics on the System, with a 
 few remarks on their efficacy in Chronic and Acute 
 Diseases 423 
 
 APPENDIX 465 
 
INTRODUCTION. 
 
 THE Laws of Organic and Animal Life, in re- 
 gard to their susceptibility of demonstration, 
 may be said to possess the properties of the 
 exact and abstract sciences. On many subjects 
 connected with these laws, direct experiments can 
 be brought forward to prove the correctness or 
 fallacy of what is advanced ; but it likewise fre- 
 quently happens that the evidence which is ac- 
 quired, even in this way, must be considered to 
 make only a distant approximation to many im- 
 portant truths. Experiments allow us to go a 
 certain length in endeavouring to develope the 
 different functions of the system ; but unless 
 the reflecting powers enable us to surpass 
 the limits prescribed to our imperfect means 
 and senses, many principles of importance, 
 which are legitimately deduced from general 
 
Xll INTRODUCTION. 
 
 facts and phenomena, would be too unconnected 
 in their relations to serve any practical or useful 
 purpose. When the animal system is patiently 
 investigated, by means of well-directed experi- 
 ments and deliberate observations, many mys- 
 teries are cleared up, and many intricacies are 
 solved. When the laws of the constitution are 
 thus examined, the results are similar to those 
 that DUGALD STEWAIIT has described in respect 
 to the operations of the mind, when studied with 
 care : " Upon a slight attention to the oper- 
 ations of our own minds, they appear to be so 
 complicated, and so infinitely diversified, that it 
 seems to be impossible to reduce them to any 
 general laws. In consequence, however, of a 
 more accurate examination, the prospect clears 
 up ; and the phenomena, which appeared at first 
 to be too various for our comprehension, are 
 found to be the result of a comparatively small 
 number of simple and uncompounded faculties, 
 or of simple uncompounded principles." 
 
 We must guard against being too indulgent 
 either to the experimentalist or theorist. The re- 
 sults obtained by the former require a more criti- 
 cal investigation than they generally receive, 
 
INTRODUCTION. Xlll 
 
 not because we should be disposed to doubt the 
 observations of an individual engaged in experi- 
 mental inquiries, but because the reasoning which 
 he founds, or the principles which lie deduces from 
 important results, are occasionally far from being 
 either legitimate or correct. 
 
 The experimentalist seldom commences his 
 practical inquiries without having some precon- 
 ceived view or principle to establish or refute, 
 tending to direct these studies ; and whatever be 
 the nature of the conclusions,he is apt to seize and 
 apply with avidity such only as are consonant with 
 his own opinion. Although the reader is not 
 liable to be blinded by the feelings and train of re- 
 flection which regulate the proceedings of the 
 experimentalist, yet he is liable to be biassed by 
 the plausible manner which generally accom- 
 panies the statement of simple facts, on account 
 of the variety of views which are closely inter- 
 woven with them. 
 
 The experiments of WILSON PHILIP, advanced 
 to prove his peculiar opinions in regard to ani- 
 mal heat and digestion, are the best illustrations 
 that can be brought forward to shew that expe- 
 riments themselves, although correct, are occa- 
 
INTRODUCTION. 
 
 sionally more liable to mislead than even the 
 deductions of theory, if they are regarded by a 
 mind neglecting to generalize the facts presented, 
 to note the relations between objects that are 
 manifest, or to refer those phenomena, that have 
 no obvious connexion to explain them, to the 
 most probable or general law of the animal eco- 
 nomy. This method of investigating the laws 
 of the system has been entirely neglected by 
 WILSON PHILIP, and to a certain extent by 
 BRODIE, and others engaged in similar physiolo- 
 gical pursuits. The former gentleman divided 
 the par vagum, and found, as a consequence of 
 this operation, that the function of digestion was 
 very much retarded or destroyed : from this effect 
 he concluded, that digestion depends on 7iervous 
 influence; but, what is somewhat extraordinary, 
 while he observed the animal breathe with 
 great difficulty while he remarked its temper- 
 ature to diminish 15 or 20 degrees, nay, even 
 after the death of the animal, when the lungs 
 exhibited the colour and congested appearance of 
 the liver he never for a moment seemed to ima- 
 gine that the proper performance of respiration, 
 and the normal circulation of the blood, tvere con- 
 
INTRODUCTION, XV 
 
 ditions at all essential to the function of digestion. 
 The same observations apply to the rest of his 
 mutilations of the nervous system, in respect to 
 animal heat and digestion. As the consideration 
 of the former occupies the greater part of the fol- 
 lowing volume, I have attended critically to the 
 views of those who suppose the nervous system to 
 be the efficient agent in maintaining the tempera- 
 ture of the body. I have not, on all occasions, per- 
 formed experiments in order to prove the correct- 
 ness of my own opinions ; but have, when it was 
 possible, taken the results of the experiments of 
 others as data for my own reasoning. This plan 
 is closely followed in several chapters, in which 
 I attempt to shew the fallacy of principles ad- 
 vanced by WILSON PHILIP, Dr EDWARDS of 
 Paris, JOHN HUNTER, and others. 
 
 I have not brought forward the varieties of 
 opinion on every physiological subject treated 
 in this work. My object has been to notice the 
 views of those whose originality and importance 
 merit repetition and consideration ; nor have 
 I been particularly desirous of developing mi- 
 nute details which naturally flow from general 
 principles. 
 
 
X vi I N TRODUC T ION. 
 
 Physiology, within a few years, has under- 
 gone material changes. There is scarcely a de- 
 partment of this science that has not been the 
 subject of experiment or theory. The anatomy 
 and physiology of the Nervous system have been 
 particularly studied. Among the list of those 
 who have distinguished themselves in this walk of 
 science, we cannot forego mentioning the names 
 of GALL, MAGENDIE, LEGALLOIS, DEMOULINS, 
 FLOURENS, and BELL. Our own countryman 
 may probably be considered as the most valuable 
 contributor to our knowledge of the nervous 
 system. His discovery of the difference between 
 the nerves of motion and of sensibility belonging 
 to the spinal cord and medulla oblongata has 
 one property to recommend it, which places it 
 pre-eminently above the contributions of his 
 contemporaries: // has important relations to 
 practice. But although others may have been 
 less fortunate in their scientific investigations, 
 it is an incumbent duty to express admiration of 
 the zeal and talent, with which they have devoted 
 themselves to such pursuits; audit is equally a duty 
 to acknowledge the benefits they have conferred, 
 
 
INTRODUCTION. XVli 
 
 and the impulse they have given to experimental 
 physiology. 
 
 It is not improbable that we shall continue to 
 labour in the study of the nervous system long 
 and patiently before we shall be capable of un- 
 derstanding satisfactorily its functions. Much 
 has already been said and accomplished to dissi- 
 pate the obscurities which hang over the phe- 
 nomena it developes, but, at present, we possess 
 only an outline of its important offices. 
 
 When physiologists knew less than they do 
 at present, the production of animal heat was as- 
 cribed to chemical changes in the lungs, as it was 
 observed that similar changes, occurring without 
 the system, are accompanied by a disengagement 
 of caloric ; but since particular attention has been 
 paid to the nervous system, others have advan- 
 ced a variety of opinions and experiments, in- 
 tended to prove that animal heat is a secretion, 
 or that this system is intimately connected with 
 its production. The former opinion has been 
 promulgated and supported by WILSON PHILIP 
 with ingenuity; and the latter, in our own 
 country, has been fully developed by BRODIE, 
 with considerable diffidence and judgment. The 
 
XViii INTRODUCTION . 
 
 mind, in taking a view of the different theories 
 that have been advanced in order to account for 
 the generation of animal heat, is continually 
 confused by their variety and discrepancy. 
 
 It would be a waste of time to enumerate the 
 various hypotheses that have been formed from 
 the age of HIPPOCRATES to our own. The first 
 rational view was that stated by BLACK, in 
 which he regards the respiratory function as 
 producing changes upon the inspired air analo- 
 gous to those attendant on combustion. This 
 idea was eagerly adopted by LAVOISIER, and 
 was subsequently modified by him. The objec- 
 tion to the original view of BLACK is, that if the 
 disengagement of caloric take place in the lungs, 
 these would be consumed, or would become 
 much warmer, from the nature of their office, 
 than any other part of the body. This conse- 
 quence has appeared so obvious, that no one, 
 since the time of BLACK, has dared to support 
 the same opinion. The experiments of CRAW- 
 FORD appeared to remove every difficulty which 
 the subject presented. They seemed to prove that 
 the capacity of arterial blood for caloric is su- 
 perior to that of the venous. This circumstance 
 
INTRODUCTION. XIX 
 
 would prevent the sensible heat of the blood in 
 the lungs being greater than that of the rest of 
 the system, as the quantity generated by the 
 chemical changes is immediately lost in the 
 greater capacity of the arterial fluid. A few 
 years ago, Dr JOHN DAVY investigated the ca- 
 pacity of the arterial and venous blood, and his 
 experiments are by no means favourable to the 
 conclusions of CRAWFORD. The difference of 
 capacity between the arterial and venous fluids 
 was observed to be so much less than what is 
 stated by the latter gentleman, that the conser- 
 vation of uniform temperature is scarcely to be 
 explained by it. Indeed, the arterial blood is al- 
 lowed by MENZIES, PL.ENK, DAVY, MAGENDIE, 
 THENARD, and many others, to be at least one 
 degree warmer than the venous. If this be 
 correct, it militates considerably against the 
 doctrine of CRAWFORD. Since the completion 
 of this work, an idea has struck me, which 
 appears sufficient, in conjunction with prin- 
 ciples already stated, to explain satisfactorily 
 the source of animal heat. It does not militate 
 against the principles which have been deve- 
 loped in the present Experimental Inquiry. 
 
XX INTRODUCTION. 
 
 Throughout this I have laboured to attain a 
 knowledge of those conditions of the system which 
 promote or retard the generation of animal heat, 
 and these have little connexion with any par- 
 ticular theory. The present view may therefore 
 be considered as an important addition to what 
 has been already said on the cause of animal 
 heat. The explanation I shall propose goes far 
 to support the doctrine of BLACK, in which the 
 increase of heat is attributed to chemical changes 
 in the lungs. It is now, I believe, almost uni- 
 versally allowed, that the arterial is warmer than 
 the venous blood, and it is more than probable 
 that this result depends on chemical action. 
 By taking into consideration, that a small quan- 
 tity only of the air within the lungs is at any one 
 moment deteriorated, and, still further, that the 
 left ventricle contracts 70 or 80 times per minute, 
 in order to propel the arterial blood which is 
 transmitted by the lungs, we shall have reasons 
 sufficiently ample to account for the possibility 
 of these organs bearing such changes, and for the 
 ease with which the system is supported in an 
 equable temperature. If the body be supposed 
 to possess 30 pounds of blood, and the heart to 
 
INTRODUCTION. XXI 
 
 transmit at each contraction two ounces, and to 
 contract 75 times per minute, we shall find that 
 the whole mass of blood will pass through the 
 lungs once every three minutes, or twenty times 
 per hour. As it has been proved by direct expe- 
 riment that the blood acquires at least one de- 
 gree of heat in passing through the lungs, it 
 necessarily follows, at this moderate calculation, 
 that the system will receive 20 degrees of heat in 
 an hour, or 240 degrees every twelve hours. If the 
 respiration be accelerated, and the contractions 
 of the heart be increased to 100, the mass of the 
 blood will circulate through the thoracic organs 
 in one-fourth less time than is stated above, and 
 consequently the temperature will be augmented 
 one- fourth : the increase of one degree, instead of 
 being repeated every three minutes, will be re- 
 peated every %\ minutes. 
 
 According to the doctrine of CRAWFORD, 
 the evolution of heat is confined to the ca- 
 pillaries distributed throughout the body ; but 
 the present explanation of the manner in which 
 the system acquires 20 degrees per hour, or 
 240 every twelve hours, is unfavourable to such 
 an opinion, as it proves that the lungs transmit an 
 
XX11 INTRODUCTION. 
 
 immense quantity of sensible heat to the body, 
 a quantity, it is highly probable, sufficient for 
 every organic necessity. 
 
 From this view of the chemical changes in the 
 lungs, it is apparent that the various internal 
 parts of the system will possess, as nearly as pos- 
 sible, the same degree of animal heat. The 
 blood which the left ventricle sends out at one 
 contraction, is calculated to supply the deficien- 
 cies incurred by an equal portion which is re- 
 turned to the right auricle ; and as the whole 
 circle of circulation is completed in two or three 
 minutes, there can scarcely be a perceptible dif- 
 ference in the temperature of the different parts 
 of the system. It is not my intention to give 
 any opinion on certain minute points connected 
 with the chemical theory. Concerning these, 
 the most distinguished chemists are at variance ; 
 and, therefore, it would be presumption in me to 
 offer even a conjecture on subjects to which I 
 have not paid an exclusive attention. The pre- 
 sent volume cannot be considered to contain a 
 complete sketch of the Phenomena of Organic 
 and Animal Life, employing this term agreeably 
 to the division and reasoning of BICHAT, but 
 
INTRODUCTION. XX111 
 
 this incompleteness is to be attributed to thejcon- 
 siderations which have induced the Author to 
 postpone the publication of the second and last 
 volume on the Phenomena of Organic and Ani- 
 mal Life. 
 
 I cannot conclude without making my warm 
 acknowledgements to those Gentlemen who 
 have assisted me in my Experimental Inquiries. 
 I can but feebly express the zeal and ability with 
 which Mr HAMILTON, Surgeon, has on all occa- 
 sions assisted me ; nor must I forget to mention 
 my obligations to A. T. HOLROYD, Esq. Christ 
 Coll. Cambridge, for the attention and talent 
 which he devoted to some of the most important 
 of these experiments. I am also materially in- 
 debted to GEORGE W. CHESTER, Esq. for many 
 advantages which I have derived from his know- 
 ledge of minute anatomy, and of professional 
 subjects. To Mr KEMP, Lecturer on Practical 
 Chemistry, Edinburgh, and to Mr HARDY and 
 Mr MURRAY, Medical Students, I have also to 
 return my thanks for their kind assistance. 
 
ERRATA. 
 
 Page 30, line II, for Foyer raid Floyer. 
 
 48, line 29, /or lOOf raid I05f . 
 
 357, line 21,/ar, and its derangement re a d, and the derangement of 
 the liver. 
 
EXPERIMENTAL INQUIRY, <fcc. 
 
 CHAR I. 
 
 Animal heat is not in the direct ratio of the quan- 
 tity f oxygen inhaled, but in the inverse ratio 
 of the quantity of blood exposed to this principle. 
 
 I. THE investigation of those laws that regu- 
 late the animal economy is at all times import- 
 ant, as a proper knowledge of these may enable 
 us to support the healthy operations of Nature, 
 or correct their occasional deviations. The sub- 
 ject of heat, from its extensive action and vital 
 influence on animal and vegetative life, demands 
 the closest attention. Many experiments have 
 been performed to elucidate the difficulties which 
 surround this department of science, and cer- 
 tainly much has been done towards removing 
 them ; but it is not presumption to assert that 
 great obscurity still hangs over some of the 
 most essential points. 
 
 II. It can scarcely be denied, that the func- 
 tions of the lungs are instituted for the purpose 
 
 A 
 
2 THE LAWS OF ORGANIC 
 
 of disengaging from the blood a portion of the 
 excrementitious matter of the system, and also 
 for the purpose of regulating the generation of 
 animal heat. Although these principles are ac- 
 knowledged to be correct in their general accep- 
 tation, it is still believed that animal heat does 
 not bear an exact ratio to the number of respira- 
 tions ; and, moreover, by some it is advanced, 
 that the nervous system is the" source to which 
 this must be either altogether or in part attri- 
 buted. That animal heat is not proportionate 
 to the number of respirations, is evident to every 
 one that has paid any attention to the subject ; 
 but this consequence does not imply that it is 
 not exclusively derived from the changes which 
 the blood undergoes in the lungs, nor does it in 
 the least favoiir the opinion that it is a secretion,* 
 or that it is to be ascribed to the nervous system, 
 agreeably to the opinion of Mr BRODIE. 
 
 III. Respiration is composed of two acts, inspi- 
 ration and expiration : the former is accompanied 
 by an enlargement of the chest and renewal of 
 atmospheric air ; the latter, by the approach of 
 
 * " The experiments related in the last chapter, compared 
 with those on secreting surfaces, seem to me to prove, that the 
 caloric, which supports animal temperature, is evolved by the 
 same means, namely, the action of the nervous influence on 
 the blood, by which the formation of the secreted fluids is ef- 
 fected, and, consequently, that it is to be regarded as a secre- 
 tion." An Experimental Inquiry into the Laws of the Vital 
 Functions, by A, P, WILSON PHILIP, M. D. F. R. S, E. 
 
AND ANIMAL LIFE. 3 
 
 the parietes of the thorax, and the expulsion of 
 the deteriorated air. 
 
 IV. The object I have in view in the present 
 chapter, is to shew, that these two acts of respi- 
 ration have each an independent function, which 
 is continually regulating the distribution of the 
 blood throughout the system, and consequently 
 producing considerable modifications in its cir- 
 culation in the lungs. The principles, if found 
 satisfactory, will explain, in a beautiful and con- 
 sistent manner, a variety of phenomena intimately 
 related to organic and animal life. 
 
 V. Physiologists have patiently investigated 
 the changes which the air experiences during 
 respiration, the conditions of arterial and venous 
 blood, and the influence of internal and external 
 means in diminishing or increasing the genera- 
 tion of animal heat, but have neglected to ascer- 
 tain in what way this principle is modified by 
 the different proportions of blood existing at diffe- 
 rent times within the chest. 
 
 VI. This omission is somewhat extraordinary, 
 but it is principally to be referred to two causes ; 
 first, the belief that the circulation of the san- 
 guineous fluid is continuous and equable; and, 
 in the second place, to the nature or direction of 
 the experiments, the greater part of which was 
 confined to the lower animals. That the blood 
 is at all times in motion in every part of the 
 body, cannot be called in question ; but it is far 
 
4 THE LAWS OF ORGANIC 
 
 from being regular either in velocity or quantity 
 in any given point, even for a series of hours, 
 Many experiments were made on the lower ani- 
 mals to elucidate a few of the above observations, 
 but, by attending to these, it was almost impossi- 
 ble to appreciate the precise influence of inspira- 
 tion and expiration upon the system. Except by 
 direct experiment this could be ascertained only 
 by repeated observations on man himself, when 
 excited or depressed by the emotions of the mind, 
 as it is then that these powerful states exhibit 
 each of these acts in its extreme developement 
 and its subsequent results. 
 
 VII. The experiments of Dr BARRY* fully 
 prove that the blood during inspiration circu- 
 lates with freedom through the lungs, but that 
 during expiration the contrary is the case. 
 
 Dr BOSTOCK, in alluding to these experi- 
 ments, observes, " The obvious objection to such 
 experiments in the abstract is, that they apply 
 to what occurs in extraordinary states of the res- 
 piration rather than to its ordinary action, and 
 that, in the healthy condition of the system, the 
 different states of the thorax cannot be perceived 
 to affect the pulse." With these remarks of this 
 distinguished physiologist I cannot agree. 
 
 VIII. In the first place, if, in a violent in spira- 
 
 * Vide Experimental Researches on the Influence of 
 Atmospheric Pressure upon the Circulation and Absorption ; 
 8vo, London, 1826. 
 
AND ANIMAL LIFE. 5 
 
 tion, the blood ascends in a tube attached to the 
 jugular vein of an animal, it proves, even when 
 this act is forced, that this is its natural tenden- 
 cy, or otherwise it would not occur ; and if we 
 conceive the inspiration of a milder character, 
 the fluid will rise less, but it will not fail to 
 shew its ordinary disposition. He also observes, 
 that " the different states of the thorax cannot 
 be perceived to affect the pulse." This is very 
 true ; but it is no objection. The alternate mo- 
 tions of the thorax are obvious, and the pulse is 
 found regular when those are in their natural 
 condition, but whenever these are in atiy way 
 disturbed the former is immediately deranged, 
 shewing that the regularity of the pulse depends 
 on the regularity of the alternate motions of the 
 chest, and not that it is uninfluenced by them. 
 By taking a few deep inspirations for a minute, 
 I can raise the pulse ten beats in that period, 
 diminishing proportionably its strength ; but as 
 soon as the two acts of respiration are restored, 
 the pulse returns to its usual condition. 
 
 IX. The early Physiologists endeavoured to de- 
 monstrate the opinion which Dr BARRY supports; 
 and this is the view that Dr CARSON has given in 
 his work on the Motion of the Blood, published 
 in 1815. " The motion of the blood, while it flows 
 in the veins, is produced by the force of the 
 heart and arteries urging it behind ; by the ab* 
 sir action of a share of the atmospheric pressure jrwn 
 
6 THE LAWS OF ORGANIC 
 
 it in front , in consequence of the resiliency of the 
 lungs interposing its influence in the intervals 
 between the contractions of the heart ; and by 
 gravity, which is rendered available in this case 
 by the projection of the arteries and the diastole 
 of the auricles." The reader will do well to per- 
 use with great care this ingenious work: its 
 merits have never been sufficiently estimated. 
 
 Mr CHARLES BELL* endeavours to shew that 
 Nature has been particularly solicitous topreserve 
 the act of inspiration, as this is " secured by a 
 double provision of nerves, viz. those which 
 come out from the sides of the spine, and those 
 which descend from the neck, when the act of 
 expiration is provided for solely through the 
 former." He still farther says, " These nerves, 
 which govern the muscles of inspiration, are 
 linked more intimately by sympathy with the 
 state of circulation and respiration ; for we see 
 in disease, as in experiments on animals, that, 
 when the powers of life have run low, the sym- 
 pathy is still exerted with such sudden catch- 
 ings of the muscles of inspiration, and with an 
 effort so powerful and unexpected, as to startle, 
 while the expiration is soft and without effort," 
 &c.f " These considerations exhibit the impor- 
 tance of the act of inspiration over that of ex- 
 
 * An Exposition of the Natural System of the Nerves 
 of the Human Body, p, 239. 
 f Ibid. p. 
 
AND ANIMAL LIFE. 7 
 
 piration, and prove the necessity for those ex- 
 terior nerves of respiration."* 
 
 X. I have not brought forward the above ex- 
 tracts as additional authority to strengthen my 
 opinion, but for the purpose of shewing that his 
 ideas in regard to the phenomena of inspiration 
 and expiration are not consistent with more en- 
 larged views on this subject. The sympathy 
 of which he speaks, existing between the nerves 
 which govern the muscles of inspiration and the 
 state of circulation and respiration, arises from 
 the painful anxiety occasionally felt from accu- 
 mulation of blood in the lungs, whether from 
 mental emotions, fatigue, or disease : and as this 
 state of the chest is accompanied by the sensa- 
 tion of dissolution, the individual makes repeat- 
 ed involuntary inspirations, and these inspirations 
 are proportionate in degree to the severity of the 
 cause and the strength of the constitution. The 
 sudden catches are referrible to acute and instan- 
 taneous sensations, produced by conditions in 
 the mode of circulation which are incompatible 
 with the continuance or well-being of life. The 
 nerves appear more intimately linked by sympa- 
 thy to the state of the circulation and respiration, 
 because, in those extreme cases of inspiration to 
 which he alludes, the action of the system is so 
 oppressed that the means which Nature employs 
 
 * Ibid. p. 
 
8 THE LAWS OF ORGANIC 
 
 to overcome it, or which are occasioned by it, 
 must necessarily disturb " the state of circula- 
 tion and respiration" to a more obvious extent 
 than expiration. The latter act is " soft and 
 without effort," not because it is deficient in cer- 
 tain nervous fasciculi, but because it is not ex- 
 cited by those momentous and painful occasions 
 which characterise the former. The act of cough- 
 ing, and the violent state of respiration after run- 
 ning, shew, whenever there is the necessity for 
 expiratory motions, that these are performed in 
 a manner as manifest as the inspiratory, which 
 proves that their character is not *' soft and with- 
 out effort," from the cause assigned by Mr BELL. 
 XI. Inspiration having the tendency to in- 
 crease the quantity of blood brought to the lungs, 
 it follows, that if these preponderate, either in 
 number or perfection, over the expirations, a greater 
 proportion than usual of this fluid will be circu- 
 lating in the pulmonary tissue. The truth of 
 this is apparent in all instances in which these 
 acts exert a superior and almost exclusive ener- 
 gy. In the depressing passions of the mind, 
 particularly in fear, and in certain diseases, as 
 spasmodic asthma, a state of congestion, or un- 
 usual determination of blood to the lungs, is 
 present. This is indicated by the very quick 
 and almost imperceptible pulse, palpitation of 
 the heart, and diminution of temperature. 
 
AND ANIMAL LIFE. 9 
 
 XII. The chief phenomena of fear, and of 
 every state of mind approaching to it, are com- 
 posed of deep inspirations ; and these being more 
 numerous or complete than the expirations, the 
 blood gradually ceases to flow to the surface of 
 the body and the extremities, making the former 
 pale and the latter cold ; and this fluid, of ne- 
 cessity, is retained in the abdominal and thoracic 
 viscera ; these, containing more than is proper 
 for the operation of their function, the pulse is 
 observed to loose its fulness and strength, and to 
 become weak and frequent. This change is in 
 accordance with the condition of the lungs, which, 
 having more more blood of a less stimulating 
 quality than what is natural, must make a greater 
 demand upon the action of the heart, and, when 
 this is so great as almost to overwhelm it, palpi- 
 tation is the consequence ; but when the demand 
 is less, the heart is enabled to transmit the blood 
 it receives, which, however, as will be hereafter 
 explained, is deficient in its ordinary stimulating 
 qualities, and therefore does not excite the strong 
 and full contractions of this organ ; but the ne- 
 cessity of continuing its action being imperative, 
 the heart performs, in frequency and feebleness, 
 what is previously accomplished in slowness and 
 energy.* 
 
 XIII. This peculiarity of the pulse, agree- 
 ably to certain alterations in the functions of 
 
 * Vide Appendix for a full explanation of this and the pre- 
 ceding section. 
 
10 THE LAWS OF ORGANIC 
 
 the lungs and heart, is not confined to depress- 
 ing emotions of the mind, or to any single dis- 
 ease, but will occur whenever the circulation of 
 the sanguineous fluid becomes becomes rather in- 
 ternal than external* whether this be occasioned 
 by exposure to cold or by affections of an asthenic 
 description. 
 
 XIV. An expiration is an act by which dete- 
 riorated air is expelled : but this is only one part 
 of its important function. It is the effect of in- 
 spiration to facilitate the motion of blood through 
 the lungs ; but it is that of expiration to retard 
 it. If, then, we have a preponderance of expi- 
 ratory actions, we diminish the quantity of blood 
 generally circulating through the respiratory or- 
 gans ; and this being the case, we shall observe 
 the heart beating with unusual vigour, at times 
 amounting to palpitation, the pulse quick and 
 strong, the countenance flushed, the whole sur- 
 face of the body exhibiting improved circulation, 
 and increase of temperature. 
 
 XV. I cannot agree with Mr CHARLES BELL 
 in thinking that Nature has been extremely so- 
 licitous to secure the act of inspiration, and that 
 expiration is of little importance comparatively. 
 He draws his conclusions from observing the 
 distribution of nerves ; and mine also are the re- 
 suit of observation, but not directed by any de- 
 sire to appreciate the value of nervous fasciculi, 
 
 * These terms are explained in Chap. IV. 
 
AND ANIMAL LIFE. 11 
 
 but rather to note the multifarious changes be- 
 longing to each act, and, from the results which 
 they present, to estimate their respective im- 
 portance, and the intentions of Nature. From 
 pursuing this mode of investigation, it is not dif- 
 ficult to prove, that, whenever inspirations ex- 
 ceed, either in number or completeness, the con- 
 trary states, whether in disease or mental trouble, 
 the powers of life are invariably depressed, and 
 occasionally endangered ; but whenever expira- 
 tions possess a similar superiority, with few ex- 
 ceptions, the system receives an additional sti- 
 mulus, the assimilating functions are invigorat- 
 ed, the mental faculties are excited, and, in fine, 
 the powers of life are augmented. If this state- 
 ment be correct, we are necessitated to acknow- 
 ledge, that the solicitude of Nature, according to 
 the opinion of Mr CHARLES BELL, has been ra- 
 ther to the injury than the benefit of the con- 
 stitution. 
 
 XVI. The lungs, from their beautiful struc- 
 ture, are every way adapted to admit of great 
 and minute distribution of blood, and also for 
 the reception of a considerable quantity of air. 
 
 The following description of the lungs, by 
 MONRO, gives an accurate idea of the provision 
 which is here made for exposing a large surface 
 of blood to the action of the air. "As our 
 lungs in a full inspiration contain about 220 
 
12 THE LAWS OF ORGANIC 
 
 cubic inches of air, the whole internal surfaces 
 of the lungs will be nearly equal to 440 square feet, 
 or nearly thirty times greater than that of the 
 whole external surface of the body." * 
 
 From the little already stated concerning the 
 action of inspiration and expiration, it is manifest 
 that the proportion of blood and air is subject 
 to great variations ; and it is my intention to 
 explain more particularly the nature and origin 
 of these. 
 
 XVII. It is not easy to ascertain the quantity 
 of air which is evolved at each ordinary expira- 
 tion ; this is so materially modified by the state 
 of the mind, system, and capacity of the chest, 
 that great discrepancies unavoidably exist in the 
 results of the most distinguished chemists. But 
 the data which I shall presume to establish, and the 
 reasoning which will naturally flow from them, 
 will be little affected by the varieties of opinion. 
 
 Dr BOSTOCK has paid considerable attention 
 to the subject of respiration, and his contribu- 
 tions are neither few nor unimportant ; and, on 
 this account, I shall draw my deductions from 
 the experiments of this talented individual. 
 
 XVIII. By an ordinary expiration, 40 cu- 
 bic inches of air are emitted ; but after this we 
 are enabled to expel a considerable portion, and 
 this quantity is estimated at 160 or 170 cubic 
 
 * MONRO'S Elements of Anatomy, Vol. ii. p. 95. 
 
AND ANIMAL LIFE. 18 
 
 inches, " so as to give 200 or 210 cubic inches 
 as the difference between the states of ordinary 
 inspiration and of forced or extraordinary ex- 
 piration."* As it is impossible to empty the 
 lungs completely, many calculations have been 
 made concerning the quantity of the residual 
 air which must necessarily remain after violent 
 or long continued expirations ; and this most 
 probably amount to 120 cubic inches.t From 
 the above statement, it is clear that, after an 
 ordinary expiration, 280 or 290 cubic inches re- 
 main in the lungs, in other words, 7 or 7^ of 
 ordinary inspirations. What is the intention of 
 Nature in giving to the lungs a capacity suf- 
 ficient to contain almost 300 cubic inches of air 
 after the evolution of that portion which is no 
 longer fit for the animal economy ? The ex- 
 planation of this intention will throw new light 
 on many mysterious changes of the system. 
 
 XIX. The air which is received by any single 
 inspiration, does not immediately act upon the 
 blood ; its office is to supply the deficiency oc- 
 casioned by the previous expiration ; and after 
 several series of such expirations it is then brought 
 into intimate contact with this fluid, and tends to 
 continue the successive alterations which it un- 
 dergoes. 
 
 XX. The organization of the lungs allows a 
 
 * BOSTOCK'S Elementary System of Physiology, Vol. ii. p. 25. 
 f .Ibid, p 29. 
 
14 THE LAWS OF OK CAN 1C 
 
 vast quantity of blood to circulate at the same 
 moment in them ; and the same adaptation fa- 
 vours, in like manner, the more general dif- 
 fusion of the air ; so that, in the usual operation 
 of the pulmonic functions we may conclude 
 that about 300 cubic inches of air are acting 
 simultaneously upon this fluid ; and, still fur- 
 ther, that the expiration of 40 cubic inches is 
 the whole of that portion which is rendered unfit 
 for the purposes of life by the action of the blood. 
 It is impossible to suppose, that air is deteriorated 
 immediately on its being inspired ; if this were 
 allowed, the whole quantity which belongs to 
 the lungs would be unfit for its vital function, 
 as this must be contained in the air-cells and 
 subject to the influence of the capillary vessels, 
 and therefore placed under circumstances that 
 would deprive it of its properties. 
 
 XXI. This contrivance is a wise provision of 
 Nature, as it enables an individual to speak, 
 laugh, run, in fine, to accommodate himself to 
 any kind of exercise where expiratory actions 
 are required, without immediately affecting the 
 office of the lungs, which would necessarily be 
 implicated if the inspired air were instantane- 
 ously appropriated to those changes which are 
 indispensable for the continuance of life. 
 
 The short breathing which an individual ex- 
 hibits after violent exercise, as after running, is 
 
AND ANIMAL LIFE. 15 
 
 not occasioned by any condition of the heart or 
 circulation, as is generally supposed, but arises 
 from the diminution of the ordinary and station- 
 ary quantity of air belonging to the chest, and it 
 ceases as soon as the repeated inspirations have 
 re-established the order of nature. 
 
 XXII. I now propose to show in what way 
 " animal heat is not in the direct ratio to the quan- 
 tity of oxygen inhaled, but in the inverse ratio to 
 the quantity of blood exposed to this principle " 
 
 As the blood is not immediately acted upon 
 by the fresh air which is received, it follows that 
 the alterations are to be referred to that already 
 existing in the pulmonary cells ; and, moreover, 
 it is natural to suppose, if we diminish the quan- 
 tity of blood, that the chemical changes will be 
 more complete, because the air will have a less 
 portion to oxygenate. 
 
 In the words of HALLEE, " the effects of ex- 
 piration are, a compressure of the blood-vessels 
 in the lungs, a reduction of the bronchia into 
 more acute angles, a pressure of the reticular 
 small vessels by the weight and contact of the 
 adjacent larger vessels, and an expulsion of the 
 corrupted blood from the lungs, by which means 
 part of the blood hesitating in the capillary ar- 
 teries is urged forward through the veins to the 
 left side of the heart, while, at the same time, 
 that part of the blood is resisted which flows in 
 by the artery from the right ventricle. Expira- 
 
16 THE LAWS OF ORGANIC 
 
 tion, therefore, will stop the easy passage of the 
 blood through the lungs."* 
 
 XXIII. The above description is sufficiently 
 correct and explicit to shew, that the circulation 
 of the blood is impeded in expiration ; and, 
 therefore, if that which is returned by the veins 
 is partly obstructed in its passage, the obvious 
 consequence is, that the quantity in the lungs 
 will be diminishing more rapidly than the quan- 
 tity of the venous blood necessary to maintain the 
 ordinary balance between the two systems can be 
 supplied. If we suppose that the lessened capa- 
 city of the chest simply retards the flow of blood 
 from the veins, without in the least considering 
 that this diminution facilitates arterial circula- 
 tion, the lungs will contain less blood than is 
 found to exist in the well-poised states of respi- 
 ration. The lungs, as stated in XVIII., always 
 contain a considerable quantity of air ; and as this 
 is that portion which immediately acts upon the 
 blood, if we diminish this blood by a series of 
 expiratory actions, it is philosophical to suppose 
 that it will be more perfectly oxygenated, be- 
 cause a smaller quantity is submitted to the in- 
 fluence of that important agent. 
 
 XXIV. I have observed, in speaking of the 
 quantity of air contained within the chest, that 
 expiration can lessen this only to a determinate 
 
 * HALLER'S First Lines of Physiology, Vol, I. Sect. CCLXXII. 
 
AND ANIMAL LIFE. 17 
 
 extent. The same remarks will also apply to the 
 blood circulating in the lungs. If we consider 
 the favourable disposition of this organ for the 
 reception of the vital fluid, we shall be persuad- 
 ed that the portion which is transmitted by the 
 right ventricle is not that portion which is im- 
 mediately expelled by the left : several times 
 this quantity must be exposed to the action of 
 the air : and it is probable that this has its de- 
 grees of oxygenation, according to the rank 
 which it occupies in the series of changes or pul- 
 monic capillary circulation. This view explains 
 why the causes, which prevent the free return of 
 blood to the lungs, do not deprive the heart, in 
 the same ratio, of that which flows along the 
 arteries. If the heart depended on this delicate 
 adjustment or harmonious action, its function 
 would be continually liable to derangement, not 
 only on extraordinary occasions, as at present, 
 but almost on every trifling occurrence affecting 
 the system. 
 
 XXV. The blood possessing more stimulat- 
 ing qualities when expiration preponderates, the 
 heart participates in this improvement ; its con- 
 tractions are more vigorous, from its cavities 
 being excited ; and, therefore, when the acts of 
 expiration have become more moderate, or when 
 their exclusive character has subsided, the arte- 
 rial system retains, for some time, a superior 
 energy of function, indicated by fulness or 
 
 15 
 
18 THE LAWS OF ORGANIC 
 
 strength of pulse, forcible contraction of the 
 heart, more equable distribution of blood, and 
 an augmentation of temperature. 
 
 XXVI. The heart having its action increased 
 by the improved qualities of the blood, commu- 
 nicates this condition to every part of its sys- 
 tem ; the capillary vessels and the veins almost 
 instantaneously participate in it ; and if muscu- 
 lar exertion be conjoined with this, the return 
 of the blood is as much facilitated by these 
 means, as its transmission is by the heart. The 
 extremities and the surface of the body receiv- 
 ing more of this fluid, as is evident from sensa- 
 tion and external appearances, the abdominal 
 and thoracic viscera must possess less, and 
 therefore the quantity of blood circulating in 
 the lungs is not so great as in the sluggish 
 state of the body, consequently it will be bet- 
 ter oxygenated. The explanation of these 
 phenomena enables us to account for others 
 that have hitherto been considered the most 
 mysterious of the system, such as the presence 
 or absence of the buffy or inflammatory coat 
 in diseases, and in moderate or excessive ex- 
 ercise. If a local disease becomes highly pain- 
 ful, or irritates the neighbouring parts, the cir- 
 culation is disturbed, and the heart and lungs 
 are quickly implicated in the disorder, and 
 they soon establish, throughout the system, the 
 various symptoms of fever, in intensity or 
 
AND ANIMAL LIFE. 19 
 
 kind proportionate to the cause and the state 
 of constitution. In the congestive or real 
 typhoid fever, the inflammatory coat is seldom 
 present ; nor should we expect this, if we con- 
 sider the collapsed or cadaverous condition of 
 the body in this disease : the organic and 
 animal functions are universally deranged, 
 the liver and the spleen, for example, are en- 
 gorged ; vomiting, headache, delirium, the 
 small, frequent, and weak pulse, the diminution 
 of temperature, the great coldness and almost 
 insensibility of the extremities, and, lastly, the 
 petechiae, maculae, or vibices, express more elo- 
 quently than words can describe, the impover- 
 ished properties of the blood, and the cause to 
 which these changes must be attributed, viz. the 
 congested state of the lungs and internal organs, 
 on which account the blood is imperfectly oxy- 
 genated, because the inspired air has to act on a 
 quantity much greater than circulates in the pul- 
 monary cells, during inflammatory affections, 
 moderate exercise, or health. 
 
 XXVII. As I purpose, in a short time, to 
 publish a work on Fever and Inflammation, I 
 shall not at present pursue farther an investiga- 
 tion into the nature and origin of the above phe- 
 nomena. From the view which is developed, it 
 is clear that the state of the blood, in disease, 
 may mislead very much in the treatment, unless 
 we be acquainted with those causes on which its 
 
 B 2 
 
20 THE LAWS OF ORGANIC 
 
 character depends which knowledge, I regret to 
 say, has not hitherto been possessed by the medi- 
 cal practitioner ; the approaches which he has 
 made have been made by means of empiricism, 
 which occasionally teaches what is right, but too 
 often misguides by its fallacies. 
 
 XXVI II. Having explained, and, I hope, 
 established these principles, we proceed now to 
 illustrate them more fully, by a variety of other 
 applications. Since the lungs are subject to 
 great variations in the quantity of blood which 
 they receive, and since these variations influence 
 the generation of animal heat, we may state the 
 following laws as universal : 
 
 1. That, in every case, in which inspirations preponder- 
 
 ate, either in number or completeness, the pulse will 
 be small, weak, and for the most part frequent ; the 
 surface and extremities of the body pale or collap- 
 sed, and the temperature of the system less than in 
 the regular action of the two states of respiration. 
 
 2. In every instance in which expirations exceed inspira- 
 
 tions, either in number or completeness, the pulse 
 will be strong and frequent, the surface and extremi- 
 ties of the body florid and full, and the temperature 
 of the system higher than natural. 
 
 3. The influence of cold upon the surface of the body 
 
 will diminish the generation of animal heat, accord- 
 ing to the degree of congestion produced in the in- 
 ternal viscera. 
 
 4. The influence of heat applied to the same parts, will in- 
 
 crease the temperature of the body, according to the 
 
AND ANIMAL LIFE. 21 
 
 relief which it gives to the internal organs, by diffus- 
 ing more generally and equably the circulation of 
 blood. 
 
 5. The buffy or inflammatory coat of blood, in diseases 
 
 and exercise, will be proportionate cceteris parib:is to 
 the quantity and force of blood circulating through 
 the lungs, as its changes bear a ratio to those condi- 
 tions. 
 
 6. The absence, or partial existence of this symptom, in 
 
 typhoid or nervous affections, will be regulated by the 
 quantity and force of blood circulating in the lungs ; 
 but these states will be most obvious when the quan- 
 tity is the greatest, and the force the least. 
 
 7. Every exertion characterised by muscular and expir- 
 
 atory action will increase the temperature of the body, 
 and tend to equalise the circulation. 
 
 8. Every exertion characterised by muscular and inspira^ 
 
 tory action will diminish the temperature of the body, 
 and tend to destroy the regular distribution of the 
 blood. 
 
 9. The effects of respiration, on the animal economy, can 
 
 be estimated only by ascertaining the character, fre- 
 quency, and force of the acts of which it is composed. 
 
 XXIX. LEGALLOIS found, in his ingenious 
 experiments on rabbits, that, when they were 
 tied upon their back, or in any way constrained, 
 the temperature of the animal was diminished, 
 He afterwards endeavoured to discover whether 
 a smaller portion of oxygen was consumed dur- 
 ing this state, to account for the diminution. 
 Experiments instituted for this purpose require 
 
22 THE LAWS OF ORGANIC 
 
 great care and exactness on the part of the ope- 
 rator, to enable him to draw legitimate conclu- 
 sions ; indeed, from their delicate nature, they 
 are liable to several sources of error. The re* 
 suits of his experiments are not uniform, but 
 the greater number seem to shew that less oxy- 
 gen is consumed when the animal is constrain- 
 ed. " It was found, however, that, in certain 
 cases, the cooling was more rapid than ordinary, 
 even when more oxygen is consumed, owing (as 
 the author conjectures,) to the struggles which 
 are made carrying off a portion of the heat."* 
 
 It is possible, when an animal is placed in these 
 circumstances, that less oxygen may disappear, 
 but this is not the cause of the phenomena ; these 
 will be explained by referring them to a more 
 general and important principle, viz. the charac- 
 ter of the respiration and the consequent con- 
 dition of the circulation. When an animal is 
 put upon its back, the palpitation of the heart 
 is perceived, and the state of the breathing is 
 extremely hurried, from mental influence. The 
 troubled action of the heart shews it is oppress- 
 ed by the quantity of blood which is determined 
 to the lungs, occasioned by the deep inspiratory 
 acts of respiration ; and these possessing more 
 than they are accustomed to present to the 
 agency of the air, it therefore follows that the 
 
 * BOSTOCK'S Elementary System of Physiology, Vol. if. 
 p. 273. 
 
AND ANIMAL LIFE. 23 
 
 animal temperature is affected, not from the 
 want of oxygen, agreeably to his opinion, but 
 from the inefficiency of this to act on an aug- 
 mented quantity of blood. The truth of this 
 view is proved, according to my reasoning, in 
 the circumstances connected with the latter part 
 of the above sentence which I have quoted. 
 When the animal made struggles, LEGALLOIS ob- 
 served that the quantity of oxygen consumed 
 was greater than usual at the time that the 
 temperature was falling rapidly, and he con- 
 jectures that a portion of the heat was carried 
 off by these efforts. If LEGALLOIS had reflected 
 on this subject, he would have perceived the 
 evident fallacy of this explanation. In every 
 case of muscular exertion, accompanied by an 
 increased consumption of oxygen, heat is gene- 
 rated ; and although this may be carried off 
 more quickly, and to a greater extent than when 
 the body is at rest, still these conditions are not 
 sufficient to counterbalance the quantity which 
 is generated. 
 
 XXX. From the nature of the greater part 
 of the experiments I have performed on animal 
 heat, I have had every opportunity of verifying 
 the preceding remarks, and I have always found 
 the character of the respiration and the action of 
 the heart as stated in XXIX. Among the num- 
 ber of rabbits which I kept in the rooms appro- 
 priated to experiments, there was one which had 
 
24 THE LAWS OF ORGANIC 
 
 always been extremely timid : it was white and 
 full grown. From exhibiting great trepidation 
 on even a distant approach, I proposed to select 
 this for the purpose of ascertaining the influence 
 of the mind on the production of heat. I made 
 an attempt to catch it, but was unsuccessful, as 
 it almost immediately escaped into a situation 
 inconvenient to enter ; but, while here, I observ- 
 ed well the great agitation of the body, such as 
 I had not seen before, nor have I since. This 
 animal, almost directly, lost its fine healthy ap- 
 pearance and appetite ; it partook of nothing 
 after this accident, and died in two days. On 
 dissection, the lungs were found to exhibit well 
 marked symptoms of inflammation, the liver was 
 much enlarged and congested, and the intestines 
 were, in certain parts, highly vascular. The 
 stomach was full of meat, which it had taken be- 
 fore this occurrence, but which was scarcely, if 
 at all, acted upon by the gastric juice. From the 
 singularity of this case, I presented it to the 
 Edinburgh Hunterian Medical Society. Among 
 the crowded attendance of the evening was Mr 
 LiZARS,the distinguished anatomist and surgeon. 
 He and the other members examined the diseas- 
 ed parts with care, and agreed with the above 
 observations. This case, although an extreme 
 one, illustrates in a very striking manner the 
 opinion I have endeavoured to support regard- 
 Ing the changes in the distribution of the blood. 
 
AND ANIMAL LIFE. 25 
 
 from struggles or other causes, attended by in- 
 spiratory actions. 
 
 XXXI. The opinion is also much strengthen- 
 ed by the experiments and observations of Dr 
 CURRIE. The first individual which he subject^ 
 ed to cold immersion was Richard Edwards, 
 whose temperature was very soon and considera- 
 bly diminished. " To my surprise/' he says, 
 " although the attendants were rubbing him dry 
 with towels, during this time the mercury fell 
 rapidly. He was put into a warm bed, and his 
 heat, when examined under the tongue, was 87, 
 at the axilla 89. Frictions were used, and 
 brandy mixed with water administered ; but I 
 found on this, as on all future occasions, the best 
 mode of counteracting the cold was to apply a 
 bladder with hot water to the pit of the stomach, 
 a fact which I think important : This being done, 
 his shiverings, which before were severe, soon 
 ceased, and he became more comfortable.*" 
 
 In another experiment on one Richard Sut- 
 ton, Dr CURRIE remarks : " In the last experi- 
 ment, when the heat sunk rapidly, Sutton said 
 that he felt a coldness and faintness at his sto- 
 mach, which he had not perceived before, and 
 when I felt the motion of his heart it was feeble 
 and languid. In some future trials of the effects 
 
 * Medical Reports on the Effects of Water, cold and 
 warm, as a Remedy in Fever and Febrile Diseases. Appen-* 
 dix, p. 26. 
 
6 THE LAWS OF ORGANIC 
 
 of immersion in fresh water, the same coldness 
 at the stomach preceded a rapid fall of the mer- 
 cury ; and these facts, together with the effects 
 I found from applying a considerable heat to this 
 part when the body was chilled with cold, con- 
 vince me that there is some peculiar connection 
 of the stomach, or of the diaphragm, or both, with 
 the process of animal heat."* 
 
 This peculiar connection, to which Dr CURRIE 
 alludes, has nothing whatever to do with the 
 direct generation of animal heat. The state of 
 the heart and pulse, and the relief which the in- 
 dividual experiences on the application of warmth 
 to the pit of the stomach, show that the heart 
 and the lungs are oppressed by the congestion of 
 blood, and that the stomach is also in the same 
 state. From the situation of the lungs and heart, 
 it is impossible to apply any means so as imme- 
 diately to influence their functions ; but, in re- 
 gard to the stomach, liver, and spleen, the con- 
 trary is the case ; and as these are engorged in the 
 same manner as the thoracic viscera, the direct 
 application of heat produces instantaneous effects 
 in them, and the improvement is transmitted to 
 the others less favourably circumstanced. The 
 nature of this improvement is accelerated circu- 
 lation ; the blood is evacuated from the parts to 
 which the bladder is placed, as is always the case 
 
 * Ibid, page o5> Appendix. 
 
AND ANIMAL LIFE. 27 
 
 in congestion when the capillary and larger ves- 
 sels have their action increased, whether by heat, 
 galvanism, or stimulants ; and these parts being, 
 in some measure, disburdened of their own in- 
 dividual load, are prepared to take off a por- 
 tion from the lungs and heart ; or the excited ac- 
 tion of their vessels is communicated to those or- 
 gans ; and from this cause, or rather from the 
 combination of the two, the respiratory function 
 speedily regains its ordinary degree of activity, 
 and re-establishes throughout the system the ef- 
 fects of its invigorated energy.* 
 
 XXXII. It is imagined by some authors of 
 distinction, that an explanation founded on phy- 
 sical principles is insufficient to account for the 
 phenomena : they are disposed to attribute the 
 beneficial consequences to nervous influence or 
 connection ; but as they have not yet favoured 
 the world with reasons, beyond mere surmises or 
 hypotheses, we must adhere to that explanation 
 which is strengthened by so many obvious ef- 
 fects in close relation to the cause assigned, that 
 it is almost impossible to observe one without 
 becoming acquainted with the other. 
 
 * Dr KELLIE, some years ago, proposed the attempt to 
 stop the cold stage of intermittent fever, by applying the 
 tourniquet to the inferior extremities, and it has certainly 
 been successful. The ancients also employed ligatures for 
 the same object, and in a similar manner. The former was 
 the suggestion of physiological principles, the latter of empiri- 
 cism. 
 
28 THE LAWS OF ORGANIC 
 
 XXXIII. Dr EDWARDS, in his valuable work, 
 " De I'lnfluence des Agens Physiques sur la 
 Vie," brings forward many instances to shew, that 
 animal heat is not evolved in the direct or any 
 proportionate ratio to the number of respira- 
 tions. In speaking of birds, in which he made 
 a variety of experiments, he observes, " Quand 
 ils sont tres-pres de 1'age ou ils peuvent soutenir 
 leur temperature a 1'air, voici ee que j'ai observd 
 chez plusieurs individus dont j'ai donne les ob- 
 servations detaillees dans les tables ; un d'eux 
 avait 40 et 90 inspirations par minute. Retire 
 du nid, et expose a 1'air de 1'appartement, qui 
 etait a 18, il perdit dans un quart d'heure 3 
 cependant sa respiration c'etait accelcree. II 
 arriva a 120 inspirations qui se soutinrent pen- 
 dant vingt-minutes. II s'etait alors rechauffe 
 d'un demi-degre ; quelque temps apres il se 
 refroidit de nouveau ; mais sa respiration, qui 
 etait devenue un peu moms frequ'ente, acquit de 
 3'ampleur ; sa chaleur se retablit de la meme 
 quantite, et persista long-temps a ce terme." * 
 
 In attempting to explain these variations, he 
 does not seem sensible of the change which the 
 blood has undergone in its distribution affect- 
 ing the generation of animal heat. He regards 
 the augmented respiration as favourable to the 
 increase of this principle, as " multipliant le 
 
 * Dr EDWARDS, p. 510. 
 
AND ANIMAL LIFE* 29 
 
 contact de 1'air avec les organes les plus propres 
 a ressentir son influence vivifiante."* 
 
 XXXIV. It is evident, that the increased re- 
 spiration is not an effort of nature, as generally 
 supposed, to counteract the injurious agency of 
 the cold, but arises from the accumulation of 
 blood in the lungs and other internal organs, 
 which occasions a difficulty of breathing, giving 
 it a laborious and inspiratory character; and 
 therefore the tendency of this action is contrary 
 to the one taught by himself and others. 
 
 In the subsequent chapters I shall develope 
 more fully these views, and shall also point out 
 several fallacies in the general principles of this 
 able physiologist, fallacies which do not in the 
 least impugn the correctness of his experiments, 
 but expose the inaccuracy of those premises 
 whence he has drawn his most important con- 
 clusions. 
 
 XXXV. I have given several instances in 
 which increase of temperature is invariably the 
 result of muscular and expiratory action, but 
 have not yet adduced one in which there is a 
 diminution from muscular and inspiratory action. 
 The best example of the latter is asthma. The 
 individual who is subject to this spasmodic affec- 
 tion seeks, as soon as the symptoms approach, a 
 free current of air, from the painful sensations 
 of dissolution which accompany this disease. 
 
 Ibid. p. 300. 
 
30 THE LAWS OF ORGANIC 
 
 When the fit is very severe, the exertions of the 
 patient to inspire are extremely urgent ; the 
 chest and shoulders are frequently and violently 
 elevated, exhibiting, in an obvious manner, deep 
 and almost continued inspiration. The blue lips, 
 pallid countenance, collapsed features, small, 
 quick, or almost imperceptible pulse, and great 
 diminution of temperature, are of themselves 
 characters sufficient to corroborate the justness 
 of the principles propounded. 
 
 Sir JOHN FOYER says, " The scapular and 
 lumbar muscles which serve for strong inspira- 
 tion join all their force, and strain themselves 
 to lift up the breast and shoulders for enlarging 
 the cavity of the chest, that the lungs may have 
 a place sufficient for their expansion, and the 
 air be more plentifully inspired." 
 
 Dr BREE, who was subject to this species of 
 asthma, and who has also written an excellent 
 work on this disease, observes, that the animal 
 temperature is materially affected by it. He 
 has sometimes found it as low as 82 9 during the 
 paroxysm. 
 
 XXXVI. If the frequency of respiration in 
 all cases produced animal heat, should we not 
 expect that the function, when accelerated to its 
 greatest extent, would evolve a proportionate 
 quantity of this principle ? But in this example 
 we perceive that a quantity of air, much greater 
 
AND ANIMAL LIFE. 31 
 
 than what is natural, is brought into contact with 
 the blood in the lungs, and yet the temperature 
 is less than in any other disease or state of the 
 system. 
 
 XXXVIT. The intentions of Nature are not 
 at all times easy to divine. In the rude research- 
 es of science, the means by which she acts, and 
 the object she wishes to attain, are seldom cor- 
 rectly recognized ; but whenever our knowledge 
 respecting the instruments she employs becomes 
 accurate, it is easy to appreciate the applications 
 she has in view. How wisely, then, is it ordained, 
 that, in the earliest years of existence, the life of 
 the infant, from the variety of its wants, the deli- 
 cacy or sensibility of its constitution, and from the 
 many affections and changes to which that age 
 is subject, may be truly said to be composed of 
 cries, tears, and restlessness.' To ease the child, and 
 secure our own peace and comfort, our efforts 
 are directed to appease these disagreeable com- 
 plaints ; but it is fortunate that our interference 
 is not at all times successful. At the time when 
 these symptoms are present the future man may 
 be considered still in embryo, arid the develope- 
 ment of this being is regulated by the activity 
 and extent of organic functions, which are 
 adapted to unfold and maintain the various 
 powers of the in dividual. It is therefore instituted 
 that these functions shall be more than usually 
 vigorous, when present and future necessities 
 
32 THE LAWS O ORGANIC 
 
 demand attention. The frequent cries of the 
 infant are made at the expence of expiratory 
 actions, and the continuance of these renders the 
 blood stimulating, the circulation more equable 
 and quick than at any other period ; and these 
 principles being established, every organ of the 
 system soon participates in the primary improve- 
 ment, and the reciprocal influence is generally 
 diffused and felt throughout the system. 
 
 XXXVIII. In infants whose constitutions 
 are strong, we sometimes observe the facility 
 with which they are nursed ; and these being 
 well formed, and of sound health, do not require 
 the operation of extraordinary means : but those 
 in an opposite state, from their great necessities, 
 are continually excited by causes calculated to 
 lessen or remove the sources of irritation. It is 
 no objection to this view to advance, that many 
 diseases are to be traced to these actions which 
 I regard as salutary. The heart is sometimes 
 subject to aneurism, from having been too much 
 excited, either by external or internal causes, 
 by means of which too much blood, or blood of 
 too highly oxygenated properties, is determined 
 to this organ ; but these consequences are no ob- 
 jections to its utility. 
 
 XXXIX. If the nature of this chapter would 
 allow me to pursue the train of the present ar- 
 gument through the variety of its relations, it 
 would not be difficult to point out or explain 
 
AND ANIMAL LIFE. 33 
 
 many other efforts of Nature, efforts which are 
 treated as diseases, because they disturb the 
 ease and diminish the enjoyment of life. Few 
 things are more disagreeable than a cough ; 
 but I am persuaded, from the character of its 
 action, that it is rather a blessing than a curse in 
 many chronic affections, except when violent ; 
 and many acute states of the system are carried 
 off by this timely agent, particularly those which 
 precede inflammation, or which succeed the 
 severity of its symptoms, when the capillary 
 vessels have lost their usual tone and energy of 
 circulation. The precise mode of its influence 
 will be better understood when we come to the 
 subject of the action of emetics. In concluding, 
 I may remark, that it is probable that more die 
 for want of a cough than of a cough : the idea is 
 strange, but it is a legitimate conclusion from 
 facts or premises that have been carefully con- 
 sidered. 
 
34 THE LAWS OF ORGANIC 
 
 CHAP. II. 
 
 The Cause of Animal Heat. 
 
 XL. IN entering upon the investigation of 
 the present subject, I am not insensible to the 
 many difficulties by which it is surrounded. I 
 have not only to contend against the natural in- 
 tricacy or delicacy of the pursuit, but have to 
 oppose my humble opinion against others, which 
 have acquired authority and reverence from the 
 talents and respectability of those, who have trod 
 in the same path ; but, as I am stimulated only 
 by the desire of arriving at truth, opinions, and 
 not individuals, are to be considered. 
 
 The following points are those to which I 
 intend to pay particular attention, and whose 
 correctness I shall attempt to prove : 
 
 1. Animal heat is proportionate to the capacity and ac- 
 
 tivity of the lungs, not understanding by activity the 
 number of respirations, but the number and character 
 of its compounded acts, inspiration and expiration. 
 
 2. This principle is proportionate to the chemical changes 
 
 in the lungs, and the perfection of all other functions 
 is also in the direct ratio to these. 
 
 3. The nervous system has no influence whatever upon the 
 
 generation of animal heat, except in diminishing or 
 retarding those chemical changes on which it depends, 
 by destroying the natural proportions of blood sub- 
 mitted to the action of the air. 
 
AND ANIMAL LIFE. 35 
 
 4. The results of artificial inflation cannot be considered 
 
 as making even a distant approach towards those che- 
 mical changes which occur during the natural state 
 of the system. 
 
 5. The operation of poisons on the nervous system, ac- 
 
 companied by a diminution of temperature, is no 
 proof that this principle is derived from the action 
 or influence of this system, except in so far as its de- 
 rangement disorders the harmony of chemical laws 
 operating in the lungs. 
 
 6. The consumption of different quantities of oxygen, or 
 
 the evolution of different quantities of carbonic acid, 
 cannot, as is the received opinion, be regarded as a cri- 
 terion of the temperature of an animal, because " ani- 
 mal heat is not in the direct ratio to the quantity of 
 oxygen inhaled, but in the inverse ratio to the quan- 
 tity of blood exposed to this principle" 
 
 XLI. In support of the first proposition, it is 
 obvious that, in every kind of muscular exer- 
 tion, attended by expiratory actions, the tempe- 
 rature of the body is augmented ; and I have 
 shown, in the preceding chapter, that this arises 
 from the quantity of blood in the lungs being 
 less than in the unexcited state of the system, 
 not only at the commencement of the invigorat- 
 ed action, but throughout the continuance of its 
 energy. 
 
 XLII. If we diminish the respiratory action, 
 we lessen the generation of animal heat. 
 
 XLIII. If the circulation of blood in the 
 lungs and internal organs be accelerated by 
 
36 THE LAWS OF ORGANIC 
 
 warmth applied to the surface of the body, or 
 by the application of friction, heat is generated 
 in increased proportion, because the lungs, by 
 these means, are indirectly relieved of a portion 
 of blood, either natural or foreign to their normal 
 function. 
 
 XLIV. If the circulation of blood in the lungs 
 be impeded by an increased 'quantity being de- 
 termined to them, as by the depressing passions 
 of the mind, by the paroxysm of spasmodic 
 asthma, nausea, cold, and soporific medicines, the 
 evolution of heat is proportionately lessened. 
 
 XLV. In the different inflammations and 
 fevers of the system, the blood, with few ex- 
 ceptions, has the bufFy coat proportionate to 
 the degree of disturbance in the respiration and 
 circulation. It is found, from experience, that 
 inflammation of the thoracic viscera exhibits this 
 appearance in a more marked manner than the 
 same occurring in the abdomen. This is to be 
 attributed to the greater disorder of the respira- 
 tory functions ; but these are sometimes as much 
 deranged by acute diseases of the latter cavity as 
 by their own affections ; and when this is the 
 case, the appearance of the blood is of the same 
 character. 
 
 XL VI.- The bufFy coat is seldom or never 
 present without having been preceded or accom- 
 panied by an augmentation of animal tempera- 
 ture ; in fine, its extent is generally observed to 
 bear a ratio to the increased temperature, and 
 
AND ANIMAL LIFE. 37 
 
 this as invariably is proportionate to an excited 
 state of the respiration and circulation. 
 
 XLVII. In the various diseases of the thorax 
 and abdomen, characterised by congestion or 
 sluggishness of action, we have an opposite train 
 of symptoms : the blood is not of a highly florid 
 aspect, nor does it exhibit the buffy coat ; the 
 surface of the body is cold, collapsed, pale, or 
 discoloured, and every internal function is affect- 
 ed by a diminution of its regular action, and at 
 this time the animal temperature is much less 
 than natural ; proving, as evidently as the re- 
 lation between cause and effect can possibly do, 
 that the lungs are the organs which influence the 
 properties of the blood and the evolution of ani- 
 mal heat. 
 
 XLVIII. If further proofs were required, we 
 might allude to the temperature of different 
 animals, which is high or low according to the 
 amplitude of the respiratory functions : but this 
 is a subject so often discussed, and so well esta* 
 blished, that it requires little attention here. 
 
 XLIX. The nervous system lias no influence 
 whatever upon the generation of animal heat, except 
 in diminishing or retarding those chemical changes 
 on which it depends, by destroying the natural pro- 
 portions of blood submitted to the action of the air. 
 
 The experiments and views of Mr BRODIE 
 are those generally alluded to, to prove that ani- 
 mal temperature is rather the result of nervous 
 influence than of chemical changes. The re- 
 
38 THE LAWS OF ORGANIC 
 
 spectability and talents of this gentleman attach 
 consequence to his physiological investigations; 
 but his contributions connected with the pre- 
 sent subject are far from being satisfactory. He 
 has the credit of having presented a number of 
 facts, new, interesting, andimportantto the profes- 
 sion ; but, in the endeavour to explain these, he 
 has unfortunately overlooked obvious causes, 
 and has attempted to ascend to others of a myste- 
 rious or indefinite character. 
 
 After relating several experiments on rabbits, 
 all of which were inflated, and having observed 
 that those which were killed by poison, or which 
 had the spinal cord destroyed, for the purpose of 
 depriving the animal of all sensorial influence, 
 cooled more rapidly than others in which the 
 nervous system was uninjured, he remarks : 
 " The facts now, as well as those formerly ad- 
 duced, go far towards proving that the tempe- 
 rature of warm-blooded animals is considerably 
 under the influence of the nervous system." 
 
 L. For a considerable period, I have devot- 
 ed my time almost exclusively to one subject of 
 experimental physiology, viz. that of animal 
 heat ; and having performed a great number of 
 experiments, modified in almost every pos- 
 sible way, I shall select a few for the examina- 
 tion of those interested in the subject. Before 
 I bring them forward, it is necessary to state 
 that, having an objection to the employment of 
 
AND ANIMAL LIFE. 39 
 
 cold air for inflation, I contrived a small machine 
 which enabled me to use warm air, and, at the 
 same time, allowed me to ascertain its tempera- 
 ture whenever I noted that of the animal. It 
 is manifest that the air we inspire is warmed in 
 its passage to the lungs, and, therefore, it is im- 
 perative to imitate, as nearly as possible, the 
 operations of nature. As this instrument may 
 be useful to others engaged in the same pursuits, 
 I have given a description of it in the Ap- 
 pendix, to which I refer the reader. The follow- 
 ing experiment was performed with cold air. 
 The temperature of the room at the commence- 
 ment was 43, and of each rabbit 104. The 
 colour of the first rabbit was black and white. 
 It was decapitated and inflated. In all the ex- 
 periments, the rabbits were killed simultaneous- 
 ly, and the different processes attended to at the 
 same moment. " 
 
 EXPERIMENT I. 
 
 Time Minutes, Thermo, in the Rectum. 
 
 5 !"'<*'' 102 
 
 10 u \. 101 
 
 15 - 100 
 
 20 9^ 
 
 25 - 961 
 
 30 - 95* 
 
 35 - 93* 
 
 40 . 92* 
 
 45 - 91* 
 
 50 ^. x 90 
 
 60 - 88* 
 
40 THE LAWS OF ORGANIC 
 
 The colour of the other rabbit, black and white, decapi- 
 tated, but not inflated. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 101 
 
 10 - 98* 
 
 15 * 97 
 
 20 - 96 
 
 25 - 94 
 
 30 - 94 
 
 35 - 
 
 40 - 
 
 45 - 89 
 
 50 - 881 
 
 55 - 87J 
 
 60 86J 
 
 The following was also black and white, but was neither 
 decapitated nor inflated. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 100i 
 
 10 - 99 
 
 15 r 97 
 
 20 - 95 
 
 25 s$ 93 
 
 30 ,>-, 9%' 
 
 35 H. 90 
 
 40 , 8ST 
 
 45 r ; 88 
 
 50 - 87 
 
 55 - 86 
 
 60 , , 85 
 
 These rabbits were four months old, and appa^ 
 rently equally vigorous. In this experiment we 
 observe, that the one which was decapitated and 
 inflated was at the conclusion 2^ above the one 
 decapitated but not inflated, and 3^ above the 
 other, which was neither decapitated nor inflated. 
 
 By the kindness of my friends, I was enabled 
 to operate on three or four rabbits at the same 
 
AND ANIMAL LIFE. 41 
 
 time, thereby placing these under precisely the 
 same circumstances. 
 
 EXPERIMENT II. 
 
 Temperature of the room 47, and of this rabbit, decapi- 
 tated, and inflated with warm air, 103i Five months old. 
 Time Minutes Thermo, in the Rectum. Temp, of the warm air. 
 
 5 - 102 - 84 
 
 10 - 103* gj*. 86 
 
 15 . 101 . 86 
 
 20 . 100 '"* 85 
 
 25-100 - 83 
 
 30 99 80 
 
 35 - 98 84 
 
 40 - 97 " - ' 84 
 
 45 ,-,,,-j 961 80 
 
 50 - 95i - 86 
 
 55 - 94; - 80 
 
 60 94 82 
 
 This rabbit was decapitated, but neither inflated with 
 cold nor warm air. Its temperature 105 ; five months old. 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 103i 
 
 10 - 102* 
 
 15 - 10H 
 
 20 - 100 
 
 25 - 98i 
 
 30 - 97 
 
 35 - 
 
 40 - 95i 
 
 45 - 94 
 
 50 - 93* 
 
 55 - 93 
 
 60 - 92 
 
 The following was decapitated and inflated with cold air. 
 Its temperature was 105 ; it was 10 weeks old. 
 
 * I cannot account for this rise, it is the only case, in the 
 ivhole series of experiments in which this phenomenon occurred. 
 
42 THE LAWS OF ORGANIC 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 103; 
 
 10 - 102 
 
 15 - 99* 
 
 20 - 98 
 
 25 - 96* 
 
 30 - 95 
 
 35 - 93* 
 
 40 . 92 
 
 45 - 91 
 
 50 - 90 
 
 55 i 89 
 60 88* 
 
 This rabbit was neither decapitated nor inflated. Its 
 temperature 105. It was ten weeks old. 
 
 TimeMinutes. Thermo, in the Rectum. 
 
 5 -' . 99* 
 
 10 - 98 
 
 15 ,-- 96 
 
 20 ,,{ ; 95 
 
 25 -* 94 
 
 30 r!$? 92| 
 
 35 J 91* 
 
 40 - 90* 
 
 45 - 89* 
 
 50 - 88* 
 
 55 - 87{ 
 
 60 86f 
 
 The four rabbits in the preceding experiment 
 cannot justly be compared with each other, on 
 account of the great difference in age. I have in- 
 variably found that animal heat diminishes much 
 more quickly, andtoagreater extent,in the young 
 than adult rabbit, and, moreover, that the vigour 
 of the animal seems to retard very much this di- 
 minution. The first two may be compared with 
 
AND ANIMAL LIFE. 43 
 
 each other. The one decapitated and inflated 
 with warm air, at the conclusion of the experi- 
 ment, was 3^ above the other decapitated but not 
 inflated ; and we observe the first of the latter 
 two, which was decapitated and inflated with cold 
 air, to be 1 i above the one neither decapitated 
 nor inflated. It is unnecessary to bring forward 
 any more experiments in which the rabbit was 
 simply decapitated, as the following will be con- 
 sidered more conclusive and satisfactory, in which 
 the brain was removed, and the spinal cord en- 
 tirely destroyed. 
 
 EXPERIMENT III. 
 
 Temperature of the room 45, rabbit 105; inflated 
 with cold air. The colour black and white, and the age 
 four months. Decapitated, and spinal cord suddenly de- 
 stroyed. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 10 - 103 
 
 15 - 102 
 
 20 - 101 
 
 25 - 100 
 
 30 - 99 
 
 35 - 98 
 
 40 - 97 
 
 45 - 95| 
 
 50 - 95 
 
 55 - 94i 
 
 60 93* 
 
 The following was not decapitated, but merely inflated 
 with cold air. Its colour black and white, temperature 
 105 C , age four months. 
 
44 THE LAWS OF ORGANIC 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 102 
 
 10 - 10(H 
 
 15 - 100 
 
 20 - 98| 
 
 25 - 97 
 
 SO - 96 
 
 35 - 952 
 
 40 - 94! 
 45 93i 
 
 50 - 92 
 
 55 - 92 
 60 
 
 The following was neither decapitated, inflated, nor had 
 it the spinal cord destroyed, as in the first example. Its 
 colour was yellow and white, temperature 105, age four 
 
 months. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 T 104 
 
 10 - 103J, 
 
 15 ; -' 102 
 
 20 _ 100| 
 
 25 - 99 
 
 30 - 98 
 
 35 r 97 
 
 40 . 96 
 
 45 - 95 
 
 50 - 94 
 
 55 - 9& 
 
 60 9H 
 
 In this experiment, in which the first rabbit 
 was decapitated, and whose spinal cord was de- 
 stroyed, its temperature, at the conclusion, was 
 3^ above that of the second, which was not 
 decapitated, but inflated with cold air, and 2 
 above that of the last, which was not decapitat- 
 ed nor inflated, and whose spinal cord was left 
 uninjured. 
 
AKD ANIMAL LIFE. 45 
 
 When the chest of the first was examined, at 
 the conclusion of the experiment, the heart con- 
 tracted 12 times per minute in the horizontal posi- 
 tion ; allowed to remain in that situation for 
 five minutes, it contracted only once in the 
 minute ; when held up by the hind legs, it con- 
 tracted 20 times in the minute ; and when held 
 up by the fore legs, 11 times in the same period. 
 This difference in the contracting of the heart 
 was noticed accidentally by my friend Mr HA- 
 MILTON. The cause cannot be referred to the 
 flow of sensorial or nervous influence, as it pos- 
 sessed neither brain nor spinal cord, but probab- 
 ly to changes in the circulation or determination 
 of blood. 
 
 The chests of the other two were also opened, 
 and the heart of the second was found beating 
 vigorously 75 times per minute ; that of the last 
 did not exhibit the least symptom of motion ; 
 the heart was dark-coloured with venous blood ; 
 its right cavities black, and engorged with the 
 same. 
 
 The spinal cord in this, and in all other in- 
 stances, was destroyed by means of a heated 
 wire, filling as nearly as possible the cavity of 
 the spine. LEGALLOIS employed a wire of this 
 size, but WILSON PHILIP used one much finer, 
 and worked it in various directions, until he 
 conceived the nervous mass to be broken down. 
 We were seldom satisfied with thrusting the 
 wire down from the decapitated surface; the 
 
46 THE LAWS OF ORGANIC 
 
 spine was often separated at the lumbar region, 
 and the instrument was afterwards sent in a 
 direction opposite to the former. 
 
 EXPERIMENT IV. 
 
 The subjects of this experiment were old rabbits. The 
 first was decapitated and inflated with cold air, and had 
 also the spine destroyed, as in the preceding instance. 
 Temperature 106 ; colour, black and white. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 103* 
 
 10 - 103 
 
 15 - 102 
 
 20 - 101 
 
 25 - 99 
 
 30 - 98 
 
 35 - 97 
 
 40 - 95 
 
 45 r -" 94 
 
 50 & 93* 
 
 55 - 92 
 
 60 - 91 | 
 
 This rabbit was merely inflated. Its temperature was 
 105J 5 colour, grey and white. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 102 
 
 10 " - >; 10H 
 
 15 - 100 
 
 20 - 99| 
 
 25 - 98 
 
 30 - 96* 
 
 35 - 95* 
 
 40 - 95 
 
 45 - 94 
 
 50 - 93| 
 
 55 - 92 
 
 60 . 91 
 
AND ANIMAL LIFE. 47 
 
 The following was neither inflated, decapitated, nor had 
 the spinal cord destroyed. Its temperature was 105 ; 
 colour, white. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 103 
 
 10 - 102^ 
 
 15 - 10H 
 
 20 - 101 
 
 25 -V 99| 
 
 30 - 97i 
 
 35 - 97 
 
 40 - 96* 
 
 45 - 95| 
 
 50 - 94| 
 
 55 - 93| 
 
 60 ' - 92 
 
 In this experiment we perceive that the first 
 decapitated, and which had also the spinal cord 
 destroyed, lost precisely the same number of de- 
 grees as the second, which was inflated with- 
 out having undergone any mutilation ; but we 
 perceive that it suffered a diminution of 3-4ths 
 of a degree more than the one which was laid 
 upon the table to cool. 
 
 EXPERIMENT V. 
 
 Temperature of the room 40 ; rabbit 105| ; colour, black 
 and white. In this the brain and spinal cord were re- 
 moved, as in the preceding instance. 
 
48 THE LAWS OF ORGANIC 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 " 104 
 
 10 HV 104 
 
 15 - 10% 
 
 20 - 100 
 
 25 - 98| 
 
 30 -- 97J 
 
 35 96J 
 
 40 '- 95 
 
 45 - 94 
 
 50 L 93 
 
 55 ': . , 92 
 
 60 - 91 
 
 Temperature of this 1 05; leaden colour. Brain and 
 spinal cord entire. Inflated with cold air. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 104 ' 
 
 10 - 103 " 
 
 15 - 102 
 
 20 - 101 
 
 25 - lOOi 
 
 30 - 99| 
 
 35 > i^> 981 
 
 40 - 98 
 
 45 - - 97 
 
 50 1 96* 
 
 55 - 951 
 
 60 94 
 
 The temperature of the following was 100"J : colour, 
 
 grey and white. Laid upon the table t5 cool. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 >* 104 
 
 10 - 102 
 
 15 - 10H 
 
 20 '- ' 100J 
 
 25 ; - :' 99 
 
 30 - 98 
 
 40 - 96 
 
 45 - 95 
 
 50 - 94 
 
 55 - 93 
 
 60 - 91 J 
 
AND ANIMAL LIFE. 49 
 
 This experiment, although it differs in its 
 results from the preceding, yet does not mate- 
 rially, if at all, support the opinion of Mr BRODIE. 
 The rabbit whose head was removed, and whose 
 spinal cord was destroyed, lost 3i more than the 
 one in which these were entire. In Experiment 
 III. we have an example opposed to this ; but, 
 in the present one, the first of the three is only 
 | of a degree beneath the last, which suffered no 
 mutilation, nor even loss of blood,-? a circum- 
 stance that always takes place to a slight extent 
 in the removal of the head and destruction of 
 the spinal marrow. In opening the chests of 
 these rabbits, the heart of the first was found 
 contracting 70 times per minute, while that of the 
 second, in which the nervous system was whole, 
 gave scarcely a perceptible pulsation. 
 
 Finding, from a variety of experiments, that it 
 was of little consequence to the evolution of 
 animal heat whether the nervous system were 
 destroyed or left entire, I thought it possible that 
 the results might be different if an animal were 
 killed by some powerful poison. To satisfy myself 
 on thislpoint,the two following experiments were 
 instituted. In the first, inflation was not employ- 
 ed ; one rabbit was killed by prussic acid, and the 
 other by a blow upon the occiput ; and, ther- 
 mometers having been introduced into the chest, 
 abdomen, and rectum of each, they were both 
 placed upon the table. The temperature of the 
 
50 THE LAWS OF ORGANIC 
 
 room 50 rabbit 101 colour white, two 
 months old ; killed by prussic acid. 
 
 EXPERIMENT VI. 
 
 Time. Thermo, in the Rectum. Thermo. A bdomen. Thermo. Chest. 
 
 5' 99' - 99 - 98 
 
 10 - 97* - 98 - 96* 
 
 15 96* 97 - 95 
 
 20 - 95 - 96 *- * 94 
 
 25 - 93* - 94 4 $>- 92* 
 
 30 92| - 94 - 91J 
 
 35 91 1 - 93 - 91 
 
 40 - 90| - 92 - 89| 
 
 45 - 89| t u ; 91| 7 S8J 
 
 50-89 - 90* - 88 
 
 55 - 88 - 89J i ' 87 
 
 60 87 89 86* 
 
 Temperature of the rabbit 104 ; colour white ; two 
 months old ; killed by a blow upon the occiput. 
 
 Time. Thermo, in the Rectum. Thermo. Abdomen. Thermo. Chest. 
 
 10 .,- 101* ajw'si 101 > -,? 10H 
 
 15 ... ,, 99| V 99 - 99J 
 
 20 99 - 98* '-- 98J 
 
 25 97J - 97J j&) 97 
 
 30-96 - 97i - 96 
 
 35 - 95| *{P 96* .' 95 
 
 40 - 94| - 95| %?. 94 
 
 45 - 94 , rf ., 95 - 92} 
 
 50 93 - 93^ '*CV 9<2 
 
 55-92 - 93 - 91 
 
 60 91 i 92 90 
 
 The temperature of the rabbit killed by prus- 
 sic acid does not appear to have been peculiarly 
 
 affected by the poison. There is 1| of proper- 
 
AND ANIMAL LIFE. 51 
 
 tional difference in the rectum ; | of a degree in 
 the chest ; but no difference in the abdomen. 
 
 The difference in the indications of the ther- 
 mometer in these different situations is riot to be 
 attributed to variations of temperature, but, pro- 
 bably, as Dr MILLIGAN justly observed to me, is 
 to be referred to the more or less perfect embrace 
 of the contained viscera. In the thorax the lungs 
 collapse when a thermometer is introduced, and 
 thereby prevent the bulb of the instrument from 
 being completely covered, this is not the case 
 in the abdomen and rectum. 
 
 EXPERIMENT VII. 
 
 In this experiment pigeons were substituted for rab- 
 bits, and are equally convenient to inflate and operate upon. 
 Temperature of the room 56 : pigeon 106 ; decapitated ; 
 spinal cord destroyed ; inflated with cold air. 
 
 Thermo, in the Rectum. Abdomen. 
 
 10 - losr - 107^ 
 
 15 102i - 106 
 
 20 - 102 - 105 
 
 25 99 104 
 
 30 97 102 / 
 
 35 95 - 100 
 
 40 94 98 
 
 45 93 - 98$ 
 
 50 - 9H - 97 
 
 55 - 90i - 95f 
 
 60 - 89 , 95 
 
52 THE LAWS OF ORGANIC 
 
 Temperature of the pigeon 106f ; killed by prussic 
 acid. 
 
 Time Minutes. Thermo, in the Rectum. Abdomen. 
 
 10 - 103 - 105 
 
 15 - 102i - 103| 
 
 20 - 101 - 103 
 
 25 - 100 -', 102| 
 
 30 99 101J 
 
 35 - 98 IMJ lOOi 
 
 40 96f 99 
 
 45 - 96 l>*"' 98J 
 
 50 - 94^ ii s j. 97^ 
 
 55 - 93| "f ri : 96* 
 
 GO 92 95* 
 
 Temperature of the pigeon 107 ; inflated, without de- 
 capitation, or destruction of spinal marrow. 
 
 Time Minutes. Thermq. in the Rectum. Thermo. Abdomen. 
 
 10 - 106 - 105 
 
 15 - 103 - 103 
 
 20 - 102^ - 102 
 
 25 - 102 - 99* 
 
 30 - 98| - 99 
 
 35 - 97 '.- 97| 
 
 40 - 96 *, 96 
 
 45 - 94| 95 
 
 50 , 93 - 93i 
 
 55 . 91J '-, 92 
 
 60 90* - 91 
 
 In this Experiment there is little particular to 
 observe. In the first, in which Decapitation and 
 destruction of the spinal cord were performed, 
 the thermometer in the rectum fell two degrees 
 more than in the second ; but the tempera- 
 ture of the abdomen was alike in both. In the 
 last, which was inflated without destruction of 
 brain or spinal cord, the thermometer in the ab- 
 domen indicated a temperature of four or five 
 
AND ANIMAL LIFE. 53 
 
 degrees less than that of either of the other two, 
 while at the same time the thermometer in the 
 rectum of this had fallen only to the extent of 
 the first in the same situation, and 1| less than 
 that of the second. 
 
 Having, from these and similar experiments^ 
 arrived at conclusions unfavourable to those 
 proposed by Mr BRODIE, I instituted a variety 
 of others, which seemed to me calculated to 
 strengthen either the opinion entertained by 
 myself, or that adopted by this physiologist. If 
 the generation of animal heat belong rather to 
 the nervous than sanguiferous system, and if 
 galvanism be capable of performing the func- 
 tions of the former, as imagined by WILSON 
 PHILIP, the employment of this powerful agent 
 ought to be regarded as an additional means to 
 promote the generation of the principle. A 
 valuable discovery of my talented friend, Mr 
 Kemp, allowed me to make a trial without 
 the least inconvenience. The discovery to which 
 I allude is the possibility of keeping up a conti- 
 nuous stream of galvanism without the accom- 
 paniment of the shock. Unless befriended by 
 such means, it is almost impossible to apply a 
 strong galvanic power to purposes of this kind. Mr 
 Kemp kindly assisted me in the first experiment. 
 Two troughs, each of 50 two-and-a-half inch 
 plates, were used on the occasion. After these 
 were charged and connected, the positive wire 
 
54 THE LAWS OF ORGANIC 
 
 was introduced into an aperture beneath the in- 
 teguments of the spine, and the negative was 
 passed in a circular manner round the neck, pre- 
 viously denuded to ensure the transmission of 
 the galvanism. 
 
 EXPERIMENT VIII. 
 
 Temperature of the room 47 ; of the rabbit 106 ; 
 colour, black and white ; age three months. Without deca- 
 pitation or destruction of the spinal cord. Inflated with 
 cold air, and galvanism employed for the space of an hour. 
 TimeMinutes. Thermo, in the Rectum. 
 
 5 - 104 
 
 10 - 102 
 
 15 - 101 
 
 20 - 99i 
 
 25 - 98| 
 
 30 - 97 
 
 35 - 95 
 
 40 - 95 
 
 45 W,| 94 
 
 50 93 
 
 55 * 92 
 
 60 90^ 
 
 Temperature of the following, lOGa ; colour, black ; in- 
 flated as the above, without the application of galvanism ; 
 age three months. 
 
 Time Minutes. Thermo, in the llectum. 
 
 5 SI 103f 
 
 10 - 103 
 
 15 - 102 
 
 20 - 100* 
 
 25 - 99 
 
 30 - 97| 
 35 95 
 
 40 - 95 
 
 45 - 94 
 
 50 - 931 
 
 55 - ' 92 
 
 60 - 91 
 
AND ANIMAL LIFE. 55 
 
 Galvanism appears to have had no influence 
 whatever in the present experiment ; both rab- 
 bits having lost precisely the same number of 
 degrees. 
 
 EXPERIMENT IX. 
 
 Temperature of the room 46 ; of the rabbit 103| ; co- 
 lour, grey and white. Inflated with cold air. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 102! 
 
 10 - 101 
 
 15 - 99| 
 
 20 - 98| 
 
 25 - 96 
 
 so :.- 95 
 
 35 f -- 94 
 
 40 - 93 
 
 . "'".' 45 ~ , 91 \ 
 
 50 - 90J 
 
 55 - 89| 
 
 60 89 
 
 Temperature of the following 103J ; colour, white 
 and black. Inflated with cold air, and galvanism em- 
 ployed. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 5 - 102 9 
 
 10 - 101 
 
 15 99 
 
 25 - 
 30 95 
 
 35 93| 
 
 40 , 031 
 45 91 
 
 50 90 
 
 55 - 89 
 
 60 - 88 
 
56 THE LAWS OP ORGANIC 
 
 In this Experiment, as in VIII. galvanism 
 does not appear to have produced any marked 
 effect. The rabbit to which it was applied lost 
 H more than the one in which it was not used, 
 It is necessary to state, that only half of the gal- 
 vanic power of the preceding experiment was 
 employed at the same moment, viz. one trough 
 of 50 plates. This alteration was made from the 
 fear that it might before have acted too ener- 
 getically on the nervous system. 
 
 Among the preceding experiments there is 
 one in which warm air was employed for infla- 
 tion. This circumstance will appear strange, after 
 having alluded to the necessity of imitating the 
 process of nature by such means. But having prov- 
 ed, by a variety of experiments, that the warm 
 air, in every case except one, maintained the tem- 
 perature of the animal from two to three degrees 
 above that of every other, how modified soever 
 the means might be in regard to the latter, I 
 substituted cold air in the place of warm, as it 
 rendered the experiment more easy to the ope- 
 rator, and removed every objection that might 
 afterwards have been brought against the re- 
 sults. 
 
 The following experiments are the only two 
 I shall present in which warm air was used. In 
 the first, I was assisted by my friends Mr 
 CHESTER and Mr HOLROYD. This experiment 
 
AND ANIMAL LIFE. 57 
 
 is the one which forms the exception to the 
 above general rule. 
 
 EXPERIMENT X. 
 
 Temperature of the room 54 ; of the rabbit 101 J. 
 
 Time Minutes. Thermo, in the Rectum. Warm air. 
 
 15 99 '- 87 3 
 
 20 - 97* r 80 
 
 25 */ 97 * 89 
 
 30 - 96| - 85 
 
 35 - 95| - 87 
 
 40 - 95 92 
 
 45 - 94 - 91 
 
 50 - 92f , 47 
 
 55 - 91J - 84 
 
 60 91i *"* 80 
 
 Temperature of the following rabbit 104J. Inflated 
 with cold air. Both full grown. 
 
 Time Minutes. Thermo, in the Rectnm. 
 
 15 - 100 
 
 20 - 100 
 
 25 - 99* 
 
 SO - 98* 
 
 35 - 97i 
 
 40 - 96} 
 
 
 
 45 - 
 
 50 95 
 
 55 - 94i 
 
 60 93J 
 
 In this experiment, the rabbit inflated with cold air lost 
 
 3-4ths of a degree less than the above, a difference too 
 trifling to note. 
 
58 THE LAWS OF ORGANIC 
 
 EXPERIMENT XI. 
 
 The result of this experiment may be regarded as af- 
 fording an impartial view of the influence of warm air in 
 inflation. Temperature of the room 46 ; of the pigeon 
 110. In this experiment I was assisted by my friends 
 Messrs HOLROYD and DDNNETT. 
 
 Time Minutes. Thermo, in the Rectum. Warm air. 
 
 10 . -~ 108 - 70 
 
 15 - 105 - 70 
 
 20 103 - 71 
 
 25 - 102 70 
 
 30 - 101 - 71 
 
 35 - 100 -. . 70 
 
 40 - 981 70 
 
 45 98 68 
 
 50 ,- 96i 67 
 
 55 **-** 95f ' l m 68 
 
 60 - 94* 67 
 
 Temperature of the pigeon lllj* Inflated with cold 
 air. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 10 ' . , 109 
 
 15 - 107$ 
 
 20 - 105* 
 
 25 , 1031 
 
 30 - 102 
 
 35 - lOOi 
 
 40 - 98| 
 
 45 - j, 98 
 
 50 -. 95| 
 
 55 : - ; ; 93f 
 
 60 92 
 
AND ANIMAL LIFE. 59 
 
 Temperature of the pigeon lllf Neither inflated with 
 warm nor with cold air. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 10 - 109^ 
 
 15 - 106$ 
 
 20 - 104| 
 
 25 - 103 
 
 30 - 101 
 
 35 - 100 
 
 40 - 98 
 
 45 - 97i 
 
 50 - 95^ 
 
 55 -..-' 94 
 
 60 - 93 
 
 L. From the results of the preceding and si- 
 milar experiments, I was persuaded that the re- 
 moval of the brain or spinal cord had no influ- 
 ence whatever on the apparent developement of 
 animal heat, nor on the degree and velocity of 
 cooling. Still, I could not flatter myself that any 
 of the measures I designed to imitate the natu- 
 ral function of respiration, proved even the slight- 
 est increase of temperature. As I did not consi- 
 der the experiments already detailed sufficient- 
 ly decisive on this point, I proposed to arrest 
 the circulation of blood in the lungs by tying 
 the heart at its base. The animal being made 
 insensible by a blow upon the occiput, the chest 
 was immediately opened, and the object being 
 accomplished, the divided parietes were again 
 closed, and the inflation of cold air commenced 
 as in other instances. The following experi- 
 
60 THE LAWS OF ORGANIC 
 
 merits, to elucidate this subject, are not selected, 
 but presented in the order in which they were 
 performed : 
 
 EXPERIMENT XII. 
 
 Temperature of the rabbit 105*; colour white ; the heart 
 tied at the base ; two months old ; inflated with cold air. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 10 - 99* 
 
 15 - 98<- 
 
 20 - 96* 
 
 25 - 94j 
 
 30 - 93i 
 
 35 - 92| 
 
 40 - 90 
 
 45 - 88J 
 
 50 > *x 87* 
 
 55 - 86i 
 
 60 - 85* 
 
 Temperature of the rabbit 104J , colour grey and 
 white ; inflated with cold air. 
 
 Time Minutes. Thermo, in the Rectum. 
 
 10 ^V 99 
 
 15 - 98 
 
 20 - 96 
 
 25 - 94* 
 
 30 - 93 
 
 35 - 91J 
 
 40 - 90* 
 
 45 - 89| 
 
 50 - 88 
 
 55 - 87 
 
 60 - 85 
 
AND ANIMAL LIFE. 61 
 
 In this experiment, the rabbit in which the 
 heart was tied lost only half a degree more than 
 the other, which was inflated, without having 
 undergone any previous operation. 
 
 EXPERIMENT XIII. 
 
 Temperature of the room 48 ; of the rabbit 106| ; 
 colour white and grey ; full grown. Inflated with cold air. 
 
 Time. Thermo, in the Rectum. Thermo, in the Abdomen. 
 15' - 102 '- 104 
 
 20 ,-:, 101 ferii 103 
 
 25-100 - 102 
 
 30 99 - 102 
 
 35 - 98* - 101 
 
 40 - 97 - 100 
 
 45 > 96* - 99* 
 
 50 - 96 - 99 
 
 55 - 95i - 98 
 
 60 94* 97* 
 
 Temperature of the rabbit 106 ; colour grey and white ; 
 heart tied. Inflated with cold air. 
 
 Time. Thermo, in the Rectum. Thermo, in the Abdomen. 
 
 15' ~ 101 - 104 
 
 20 - 100 - 103 
 
 25 - 99* - 102| 
 
 30 - 98* - 102 
 
 35 ~ 67* - 1014 
 
 40-97 - 101 1 
 
 45 I'- 96^ - 101 
 
 50-96 - 100 
 
 55-95 - 99 
 
 60 94 - 
 
62 THE LAWS OF ORGANIC 
 
 In this example we perceive that the thermo- 
 meters in the rectum indicate precisely the same 
 loss of temperature, while those of the abdomen 
 vary li ; but this difference is in favour of the 
 rabbit whose general circulation was stopped. 
 The following experiment is the last I shall ad- 
 duce. 
 
 EXPERIMENT XIV. 
 
 Temperature of the room 45 : of the rabbit 105f ; co- 
 lour white and grey ; full grown ; heart tied. Inflated with 
 cold air. 
 
 Time- Thermo, in the Rectum. Abdomen. Chest. 
 
 15' - 100 - 102 - 103 
 
 20 - 100 , 102^ u . 103 
 
 25 - 99 102 % 102| 
 
 30 - 98| . 102 - 100 
 
 35 - 98 - 102 - 99| 
 
 40 - 97| - 101 - 98| 
 
 45 ;;> 97i - 101 - 98 
 
 50 - 97 - 101 - 98 
 
 55 - 96J - 100 - 96$ 
 
 60 96 100 96 
 
 Temperature of the rabbit 106. Inflated with cold air. 
 Time. Thermo, in the Rectum. Abdomen. Chest. 
 
 15' - 102! - !05 - 104 
 
 20 - 102 - 104 - 102 
 
 25 - 101 - 103| - lOOf 
 
 30 - 100 - 103 - 994 
 
 35 - 99 - 1024 - 98 
 
 40 99 102 . 97 
 
 45 98 101 * - 96 J 
 
 50 - 97 - 101 - 96 
 
 55 - 96* - 100 - 95 
 
 60 - 96 
 
AMD ANIMAL LIFE. 63 
 
 The results of this experiment differ little from 
 those already detailed ; and from these it appears 
 that animal heat is but slightly, if at all, disenga- 
 ged in the lungs by any artificial means we pos- 
 sess : but from this statement we are not to con- 
 clude that the lungs, in the natural condition of 
 life, are not the seat of any disengagement. I 
 have endeavoured to show, in this and the pre- 
 ceding chapter, that the temperature of an ani- 
 mal is increased or diminished according to the 
 character of respiration or mode of circulation ; 
 and I shall now attempt to explain why infla- 
 tion, however well conducted, does not materially 
 augment the temperature of the body, nor pre- 
 vent it from cooling in the same ratio as in an- 
 other unassisted by inflation. 
 
 LI. Respiration may be considered partly an 
 instinctive and partly a voluntary function, 
 whose influence is to regulate the circulation of 
 the blood, and therefore the generation of ani- 
 mal heat. If its action be disordered during 
 life, by the preponderance of inspirations, for 
 a short time, the temperature of the body di- 
 minishes almost as much as in the rabbit we in- 
 flate. The asthmatic patient, of whom Dr BREE 
 speaks, had a temperature as low as 82 in the 
 paroxysm. I have observed, in Chap. I. xix. and 
 xx. that the air inspired is not immediately ex- 
 pelled by expiration, but that a portion is emit- 
 ted probably the whole which is deteriorated, r 
 
64 THE LAWS OF ORGANIC 
 
 while a much greater quantity of air at all 
 times exists in the lungs ; and from this it is to 
 be inferred, that the successive chemical changes 
 are slow, and of a delicate description. If we 
 send in a quantity of air greater than what is 
 consistent with the laws which nature has esta- 
 blished, we destroy the concord connecting the 
 various agents ; and this abundance, instead of 
 promoting the different decompositions, tends to 
 destroy the conditions on which these depend. 
 
 LI I. During the process of inflation, the heart 
 continues to beat ; but this is no proof that the 
 circulation is in its normal state, or that the 
 lungs perform their usual office ; for these phe- 
 nomena occur in the human subject when the 
 temperature of the system has fallen consider- 
 ably. In fine, the heart occasionally palpitates 
 when the lungs are oppressed with blood ; and 
 this symptom is regarded as an increased action 
 of the organ, yet it is often accompanied by a 
 diminution of temperature. It is therefore evi- 
 dent, that the contractions of the heart are far 
 from being criteria of proper chemical changes 
 operating on the lungs. 
 
 LI II. The colour of the blood is often addu- 
 ced as showing that the venous is converted into 
 arterial as in health ; but this change of colour 
 takes place in those cases it} which respiration is 
 deranged and the temperature diminished. 
 
AND ANIMAL LIFE. 65 
 
 LIV. The alterations which the blood under- 
 goes in the lungs are probably various ; that of 
 colour is apparent : but this may be only one* and 
 the least of a series, connected with the produc- 
 tion of animal heat ; or, for any thing that we 
 know, may be an effect altogether independent 
 of those principles which maintain the tempera- 
 ture of the constitution. When venous blood, 
 without the body, is exposed to the action of 
 atmospheric air, it assumes the florid colour of 
 the arterial ; but we are not aware that this is 
 accompanied by the generation of heat. 
 
 LV. It is stated by LEGALLOIS, that he could 
 cool an animal to such a degree, during life, by 
 inflation, as to kill it ; and I have not the least 
 doubt that the temperature is, at all times, by 
 such means, materially affected. If we cannot 
 succeed in the application of this process when 
 the animal is alive, and when it in part seconds 
 our intentions, how can we expect to be more 
 fortunate when the animal is mutilated. The 
 combination of gases, and the formation of salts 
 and other substances, are regulated by definite 
 laws ; and it is well known, that if proper pro- 
 portions are wanting, or if those circumstances 
 are absent which are necessary to promote che- 
 mical action, no change whatever takes place. 
 But shall we suppose that the powers of life are 
 governed by no principle, or, in more correct 
 terms, that the action of those agents which sup- 
 E 
 
66 THE LAWS OF ORGANIC 
 
 port these, is the effect of chance ; if otherwise, 
 let it not be imagined that an imperfect imita- 
 tion of the function of respiration will furnish 
 results sufficiently accurate to allow us to speak 
 with certainty of its office. 
 
 LVI. The cause of animal temperature is at- 
 tributed by WILSON PHILIP to a secreting pro- 
 cess, similar to that which occasions the variety 
 of secretions in the system by the action of the 
 nervous fluid upon the blood. This opinion is 
 supposed to be demonstrated by direct experi- 
 ment ; and certainly a great number of facts are 
 brought forward which seem favourable to the 
 view, if such be superficially observed. He has 
 endeavoured to show the close analogy existing 
 between galvanism and the nervous fluid, by 
 numerous experiments on rabbits ; and finding 
 that the effects are the same, without consider- 
 ing the complexity of the animal economy, or 
 without looking beyond the mere application of 
 means and the production of obvious results, 
 he concludes that these two agents are precisely 
 of the same nature. The discovery of this seem- 
 ing analogy has formed an era in physiological 
 science ; and if it had been true, it would have 
 been a very close approximation to the develope- 
 ment of the most mysterious operations of the 
 system ; but I do not hesitate to say, that while 
 his experiments are to be regarded as furnishing 
 
AND ANIMAL LIFE. 67 
 
 facts, his reasoning is to be estimated as merely 
 ingenious and hypothetical. 
 
 LVII. Conceiving his opinions on this sub- 
 ject to be incorrect, I shall spare no pains, in the 
 subsequent chapter, to expose errors which are 
 capable of retarding the proper cultivation of 
 medicine for centuries, as presenting to the phy- 
 siologist established points or data to direct his 
 pursuits, on which, perhaps, he may erect prin- 
 ciples not less extensive and important than the 
 present, and thereby would continue to heap er- 
 ror on error, till at last the whole system would 
 fall, from the magnitude of its inconsistencies. 
 To do justice to the subject, it is necessary to be 
 minute and patient in the investigation of its 
 merits ; and, therefore, I shall follow as closely 
 as possible the observations and experiments of 
 this talented physiologist, for whom, as an indi- 
 vidual, I entertain the highest respect. The 
 cause of animal heat will be better understood 
 by the treatment of the following chapter, as I 
 shall have an opportunity of illustrating the im- 
 portance of respiration and circulation in regard 
 to organic functions. 
 
 E 2 
 
68 THE LAWS OF ORGANIC 
 
 CHAP. III. 
 
 Secreting surfaces are not dependent on nervous 
 communication between their own individual parts 
 and the origin of the nerves, nor does galvanism 
 re-establish or excite their particular functions 
 by maintaining such a relation. 
 
 LVIII. A function may be regarded as the 
 consequence of the inherent properties of an or- 
 gan, as the power of gravitation is attributed to 
 laws impressed on inert matter ; and as the lat- 
 ter is regulated by particular principles, so is 
 the former by the size and activity of those sys- 
 tems essential to its exercise ; but the analogy 
 cannot be continued far, from a difference in the 
 principles by which they are governed. 
 
 LIX. We observe that the kidneys are sup- 
 plied with a great quantity of arterial blood, and 
 we still further remark that the urine secreted 
 bears a proportion to this. The relations and or- 
 ganization of the secreting organs would lead one 
 to suppose that the fluid secreted is to be ascribed 
 to an extraordinary mechanism by which the pro- 
 perties of the blood are changed and appropriat- 
 ed, in one situation evolving mucus, in another 
 bile, in a third gastric juice. These products are 
 modified by two causes, disease or derangement 
 in an organ in which the operations are seated, 
 
AND ANIMAL LIFE. 69 
 
 disease or derangement of the sanguineous fluid 
 on which the adaptation has to act. 
 
 LX. The inflammation of the kidneys is an 
 illustration of the first cause. In this condition 
 its function is almost entirely suppressed ; the 
 quantity of urine which is formed is small, and 
 its discharge is accompanied by great pain. Is the 
 explanation of the phenomena to be found in 
 supposing the nerves, or in supposing the delicate 
 and beautiful structure of the parts concerned in 
 the secretion, to be diseased ? What proofs have 
 we that the nerves constitute the mechanism 
 subservient to the function? 
 
 In hysteria the urine is pale and copious ; 
 at the termination of febrile diseases it is 
 sometimes high coloured, and deposits a thick 
 sediment : In a fit of indigestion how often 
 is it turbid or of an unusual appearance ? Are 
 these alterations the effects of a nervous affec- 
 tion, or do they depend on changes induced in 
 the quality of the blood and in its mode of cir- 
 culation ? The two latter conditions are obvious- 
 ly disturbed ; but we have no evidence whatever 
 that the nerves are equally essential to secretion, 
 or equally disturbed by circumstances. 
 
 LXI. In acute cases of dropsy, depletion at 
 times removes quickly the accumulated fluid ; 
 and although it is almost impossible to ascertain 
 precisely the conditions of the sanguiferous sys- 
 tem which predispose to the effusion, or the 
 
70 THE LAWS OF ORGANIC 
 
 exact nature of those which tend to diminish it, 
 yet we are sensible that the changes from health 
 to disease, in the present instance, are connected 
 with striking modifications in the circulation of 
 the blood, arising generally from the action of 
 cold, either external or internal, after previous 
 exercise : and we still further remark, that the 
 severity of the symptoms, in every stage of the 
 affection, is characterised by increased force and 
 motion of the blood, the presence of the buffy 
 coat, the increase of temperature, and various 
 other derangements belonging to organic life. 
 If we were to state fully the beneficial changes 
 induced in the same system by bleeding, it would 
 be still more manifest that these depend exclu- 
 sively, for any thing that we know to the con- 
 trary, on the quality of the blood and the mode 
 of circulation. Secretion and absorption in this 
 example bear evident relations to general causes, 
 and to causes which are appreciable. 
 
 LXII. The function of digestion has been as- 
 cribed by WILSON PHILIP to the influence of 
 the nerves of the stomach on the materials of 
 the capillary vessels ; and, in support of his 
 opinion, he asserts that the secretion of gastric 
 juice is stopped as soon as the eighth pair of 
 nerves are divided, and that this process is re-es- 
 tablished as soon as galvanism is transmitted to 
 the organ of digestion. If the appetite be any 
 criterion of the facility with which gastric juice 
 
AND ANIMAL LIFE. 71 
 
 is secreted, or of the quantity which is already 
 poured out, it will not be difficult to arrive at 
 certain general laws which regulate the pheno- 
 mena. Every kind of exercise is a stimulus to 
 the blood ; it quickens its motion and improves 
 its properties, and these effects speedily excite 
 those parts of the system appropriated to secre- 
 tion. The abdominal viscera, without excep- 
 tion, receive the invigorating impulse, indicated 
 by the desire of food and the greater power of 
 assimilation ; the colour of the countenance and 
 the temperature of the body, and every natural 
 evacuation, is similarly benefited. But if the 
 body, instead of enjoying gentle exercise, be in- 
 active or subjected to constraint, the above 
 functions become irregular or imperfect ; or if 
 an individual be suffering from depressing pas- 
 sions of the mind, the appetite becomes almost 
 immediately fastidious or feeble ; and a variety 
 of other symptoms are present, which show that 
 the defect in the desire of food and the energy 
 of digestion is merely one of a series of conse- 
 quences flowing from the want of oxygenated 
 blood and a regular distribution of it. We have 
 no proof that the nerves in the kidneys secrete, 
 and we have as little evidence that the same 
 agents have that important office in the stomach ; 
 but if we suppose with WILSON PHILIP that 
 these act on the properties of the blood, evolv- 
 ing, in a manner unknown to us, the specific 
 
72 THE LAWS OF ORGANIC 
 
 fluid, the concession is as dangerous to his reason- 
 ing and conclusions as the former unconditional 
 statement ; as the quantity and quality of the blood, 
 in all his experiments in which galvanism was 
 not employed, and in which digestion was ar- 
 rested, were deficient in their most essential con- 
 ditions. 
 
 LXIII. We may state as a principle, that 
 whatever improves the impoverished properties of 
 the blood) or equalizes its distribution, augments 
 the secretion of gastric juice ; and that whatever 
 occasions an opposite state of the sanguineous fluid, 
 retards or destroys the Junction. 
 
 LXI V. It is not always easy to ascertain when 
 a function is capable of being performed, or, 
 in other words, what degree of general abberra- 
 tion of the system an organ will bear before it 
 is deprived of its faculty or office. The conti- 
 nuance and the force of circulation enable us in 
 some measure, at times, with precision to calcu- 
 late the extent of derangement compatible with 
 the exercise of functional power ; but the best 
 guide we possess is the temperature of the body. 
 Whenever this is much diminished, or when it 
 falls rapidly, we may rest assured, that digestion 
 will be impeded or destroyed for the time, be- 
 cause the temperature is never low, for even a 
 moderate period, without changing the properties 
 of the blood, and its usual mode of circulation. 
 Having made these observations, we are prepar- 
 
AND ANIMAL LIFE. 73 
 
 ed to appreciate the force and correctness of 
 what follows, commencing with the inferences 
 which WILSON PHILIP supposes to be legiti- 
 mately drawn from his ingenious and well con- 
 ducted experiments ; and if these be taken in the 
 order presented to the reader, we shall have a 
 better opportunity of judging of the soundness 
 of his views ; and of the value of his experiments. 
 LXV. His first and second inferences, are, " That 
 the function of secretion is destroyed by dividing 
 the nerves of the secreting organs" 
 
 " That it may be restored after it is thus destroy- 
 ed, by the galvanic influence. 9 '* 
 
 His Experiments, 44 and 45, are adduced to 
 prove the first inference. In 44, the eighth pair 
 of nerves were divided in one rabbit, in the other 
 they were laid bare, and, after being raised on a 
 probe were replaced uninjured. Both were al- 
 lowed to eat parsley after the operation. In 
 twenty hours from the division of the nerves, 
 the rabbit which had undergone this operation 
 died, and the one in which the nerves were only 
 laid bare, was immediately killed to allow the 
 experimenter to compare the two. In the latter 
 the food was digested as usual, but in the former 
 the food was found wholly unchanged by the 
 digestive process. Experiment 45 was perform* 
 ed to ascertain whether the distended stomach, 
 which was always a consequence in the rabbit 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 247. 
 
74 THE LAWS OF ORGANIC 
 
 whose nerves were divided, was to be attributed 
 to the quantity of food which the animal de- 
 voured after the operation ; and to prove this 
 point, the rabbit was not allowed to eat after the 
 division of the nerves. The stomach was still 
 distended. 
 
 JLXVI. In these two experiments he does not 
 particularize the symptoms ; but he observes, 
 " These experiments seem to leave no room to 
 doubt, that the office of the stomach is suspended 
 by dividing the eighth pair of nerves. A similar 
 observation applies to the lungs. In all the in- 
 stances in which these nerves were divided, great 
 dyspnoea we have seen come on, and the air cells 
 and tubes were found clogged with frothy mucus"* 
 If an individual suffered from tic doloureux, 
 and allowed the surgeon to divide the nerve of 
 sensation belonging to the face, he would after- 
 wards find that the sensibility of the part was 
 destroyed ; and from this operation he would be 
 permitted to conclude that this nerve gave feel- 
 ing to the face ; but WILSON PHILIP, in draw- 
 ing a similar deduction from direct experiment, 
 has apparently forgot two important considera- 
 tions : First, he ought to have ascertained that di- 
 gestion depends on nervous influence ; Secondly, to 
 have explained the nature of the relation existing 
 between the lungs and stomach in regard to their 
 functions. 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 125. 
 
AMD ANIMAL LIFE. 75 
 
 LXVII. He grants that the lungs are always 
 disordered, or rather that their office is destroyed, 
 by dividing the eighth pair. Since digestion, in 
 every instance, is modified by the action of the 
 lungs, at one time excited, at another depressed, 
 by the quality of the blood, can we for a mo- 
 ment suppose that the secretion of the gastric 
 juice will take place when the lungs have entire- 
 ly lost the power of supplying to the stomach, 
 and every other part of the body, a fluid possess- 
 ing its natural properties ? If we believe, with 
 this physiologist, that the nervous energy acts on 
 the blood transmitted to the stomach, it cannot 
 be imagined that the quality and motion of the 
 sanguineous fluid are of trifling consequence to 
 this agent. Does it possess the faculty of im- 
 proving the deteriorated properties of the blood, 
 of controlling its circulation, and, at the same 
 time, the power of converting it to the necessary 
 wants of the stomach? If such endowments 
 characterized its exercise, the function of the 
 lungs would almost be unessential to the sys- 
 tem. 
 
 LXVIII. It is stated, that the stomach and 
 oesophagus are generally found distended in 
 those rabbits in which the eighth pair of nerves 
 have been divided ; and he says " that this arises 
 from the fruitless efforts to vomit." He does 
 not explain how vomiting distends the stomach, 
 nor can I conceive the possibility, for it is prov- 
 
76 THE LAWS OF ORGANIC 
 
 ed that this organ is only slightly active in there- 
 jection of its contents. If this act were accom- 
 plished by the stomach itself, we might then con- 
 sider it probable that its muscular fibres, by repeat- 
 ed and excessive action, were debilitated, thereby 
 allowing of easy enlargement. The intestines 
 do not become distended in consequence of co_ 
 pious evacuations, but have their capacity very 
 much augmented by accumulated faeces or a col- 
 lection of air. The bladder, if ever found in a simi- 
 lar condition, has not become so from the approxi- 
 mation of its parietes from a pressure from with- 
 out, which occurs in vomiting, owing to the action 
 of the abdominal muscles, but from the influence 
 of a distending force from within. The cause 
 of this phenomenon is to be ascribed to the 
 disengagement of aeriform fluids, which gen- 
 erally happens when digestion is imperfect, 
 or when it is almost destroyed. The food 
 which the stomach receives is not acted upon in 
 the ordinary way, but the action of the gastric 
 juice in the organ is sufficiently powerful to make 
 an attempt at decomposition ; and this imperfect 
 action is attended by an evolution of aeriform 
 fluids. From the developement of this view, it 
 is clear that the stomach, like the bladder and in- 
 testines, is distended from a power exercising a 
 pressure from within, outwards, not from efforts 
 of vomiting, which are accompanied by opposite 
 physical circumstances. 
 
AND ANIMAL LIFE. 77 
 
 LXIX. We now come to the consideration 
 of the second inference, " that it (secretion) 
 may be restored, after it is thus destroyed, by the 
 galvanic influence? Experiments 46, 47, 48, 
 and 49, were performed for the purpose of 
 shewing that the influence of galvanism was 
 equivalent to that of the nerves. In the first, 
 46, in which the eighth pair of nerves were 
 divided and galvanism applied, neither dyspnoea 
 nor vomiting occurred : these invariably happen- 
 ed in every instance in which the lungs were 
 found congested with mucus, and covered over 
 with black patches ; consequently, their absence 
 shews that the circulation of the blood in the 
 pulmonary tissue was little altered ; and, more- 
 over, that its properties were but slightly modi- 
 fied. Such conditions being maintained, diges- 
 tion ought to proceed in the usual way ; and this 
 was found to be the case. The animal lived six 
 hours, and on examining the lungs the following 
 were the appearances : " The membrane of the 
 trachea was of a natural colour, and there was no 
 fluid in it. The ramifications of the bronchia in 
 the left lung were quite free from frothy mu- 
 cus. There was some fluid in the right lung, 
 though it did not appear much gorged ; there 
 was one dark spot on it. The lungs collapsed 
 imperfectly on opening the chest."* 
 Case 47. is very interesting, as it more strik- 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 125. 
 
78 THE LAWS OF ORGANIC 
 
 ingly illustrates my opinion than almost any 
 other which he adduces. Two full grown rab- 
 bits ate plentifully of parsley half an hour be- 
 fore the division of the eighth pair of nerves. 
 As soon as this operation was performed on one, 
 galvanism was applied, and continued to be so, 
 with varying degrees of intensity, for seven- 
 teen hours, at which time the rabbit died ; 
 the other, which had not been in any man- 
 ner interfered with, was then killed, and the 
 two were compared. He says, " The only 
 differences between the contents of the two 
 stomachs were the following : The food, which 
 the healthy rabbit had taken during the expe- 
 riment, was found in the cardiac portion of the 
 stomach, and digestion was going on rapidly in it ; 
 while that which the other had taken at the same 
 time was stilt in the oesophagus, and consequently 
 unchanged." It appears that the food which had 
 been taken previously to the experiment exhi- 
 bited in both an equal extent of the digestive 
 process ; and this is consistent with the state of 
 respiration during that time. After galvanism 
 had been employed twelve hours, he says, " The 
 animal seemed very composed, and breathed with 
 considerable freedom, the trough having acted 
 regularly for some hours." * Two hours after this 
 period the animal made an attempt to vomit, 
 and from this time the breathing became labo- 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 130. 
 
AND ANIMAL LIFE. 79 
 
 rious, and the severity of this symptom con- 
 tinued to increase till death. 
 
 While the lungs were enabled to act with 
 regularity, the stomach was scarcely, if at all, 
 impeded in its functions ; and this accounts for 
 the similarity in the results presented by the 
 food which had been takenbefore the operation, 
 and the irregularity or imperfection in the re- 
 spiration after the animal had been enfeebled 
 or oppressed by the operation. .Application of 
 galvanism, and the constraint of its position, 
 accounts also for the food being in the oesopha- 
 gus, and consequently unchanged, while that 
 which the other had taken was in the cardia, 
 and in part digested : so that the latter part of 
 this experiment differs little from others which 
 he offers to our notice, in which the nerves were 
 divided without being followed by the employ- 
 ment of galvanism. In accordance with this 
 opinion is the condition of the lungs as de- 
 scribed by WILSON PHILIP : " The lungs did 
 not collapse on opening the thorax, the air-cells 
 being full of a frothy and bloody serum. The 
 lungs were externally of an uniform dark-red co- 
 lour. The heart was a little increased in size, 
 and highly vascular." * 
 
 LXX. Experiment 49. on two dogs, presents no- 
 thing of importance, except that the one in which 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 132. 
 
80 THE LAWS OF ORGANIC 
 
 the eighth pair of nerves were divided, and in 
 which case galvanism was not used ,had great dysp~ 
 noea and made violent efforts to vomit in ten minutes 
 after the operation ; and in four hours, at which 
 time it was killed, " it was so weak that it could 
 not stand or move itself from the place where it 
 lay on its side." * And he farther observes, 
 " Is it possible to explain the results of these 
 experiments without admitting the identity of 
 the nervous influence and galvanism ? We must 
 either admit this, or that there is another power 
 capable of performing the most characteristic 
 and complicated functions of the nervous sys- 
 tem." f Having already made many observa- 
 tions on the character and results of these expe- 
 riments, it is scarcely necessary to discuss at 
 length the evident incorrectness of the infer- 
 ences which he deduces. 
 
 LXXI. Without supposing any identity be- 
 tween nervous and galvanic influence, the re- 
 sults are easily explained ; nor are we necessi- 
 tated, if we deny this identity, to admit, that 
 there is another power, " capable of performing 
 the most characteristic and complicated func- 
 tions of the nervous system." The views al- 
 ready developed, in conjunction with others to 
 be stated, will preserve us from this disagree- 
 able dilemma. 
 
 * Dr WILSON PHILIP on the Vital Functions, p, 156. 
 f Ibid, p. 138. 
 
AND ANIMAL LIFE. 81 
 
 LXXII. Galvanism is one of the most power- 
 ful stimulants we possess : it is capable of dis^ 
 cussing indolent tumours, of exciting the action 
 of the heart, and of improving the sluggish 
 state of the circulation. I am acquainted with 
 a gentleman who has employed galvanism in 
 two syphilitic buboes of the groin. One was 
 about the size of a hen's egg, and this, after 
 half an hour's application of a small pile 
 of forty two-inch plates, was diminished one^ 
 half; in the other, which was less, very slight 
 alteration immediately took place in its size or 
 appearance, but in this case resolution quickly 
 followed its employment. 
 
 LXXIII, The action of galvanism, in WILSON 
 PHILIP'S experiments, is similar to the operation 
 of the same power on any external tumour. 
 When transmitted to the lungs and stomach by 
 the ends of the divided nerves, it causes the 
 blood to circulate with greater facility and regu- 
 larity. In proof of this I may observe, that, when 
 its influence is discontinued for a very short 
 period, congestion immediately takes place in 
 the lungs, indicated by laborious breathing and 
 vomiting, but these symptoms as soon disappear 
 when it is reapplied; and, still further, it is ac- 
 knowledged by this able physiologist, that great 
 vascularity was generally found in those cases in 
 which galvanic influence had been employed. 
 
 If, then, this agent diminishes congestion, an4 
 
 F 
 
82 THE LAWS OF ORGANIC 
 
 promotes a more equable circulation in the lungs, 
 the blood will be better oxygenated according to 
 principles previously stated, and, therefore, as the 
 state of the stomach depends on these conditions, 
 its function will be accelerated according to the 
 correctness with which they are performed. Gal- 
 vanism will also act upon the stomach in the same 
 manner that it does upon the lungs ; but the effects 
 will here be confined to an improvement in the 
 distribution of the blood, while, in the other 
 case, it tends to improve the properties of this 
 fluid by removing all disabilities to its circula- 
 tion, and to the chemical influence of the in- 
 spired air. 
 
 If I were required to bring forward any proofs 
 in support of the influence of galvanism, 1 would 
 adduce the application of this agent to practice, 
 and the results which followed its action, as 
 stated by WILSON PHILIP himself. He says, 
 " That both the oppressed breathing and the 
 collection of phlegm caused by the division of 
 the eighth pair of nerves, may be prevented by 
 sending a stream of galvanism through the 
 lungs :"* And still further, " When there is a con- 
 siderable tendency to inflammation in habitual 
 asthma, the repeated application of galvanism 
 sometimes increases it so much, that the use of 
 this influence no longer gives relief till the in- 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 315. 
 
AND ANIMAL LIFE. 83 
 
 flammatory tendency is subdued by local blood- 
 letting." * It was found most beneficial in 
 those cases " which were least complicated with 
 other diseases, the chief complaint being a sense 
 of tightness across the region of the stomach, im~ 
 peding the breathing." 
 
 Are the oppressed breathing and collection of 
 phlegm prevented by galvanism acting in a pe- 
 culiar manner upon the nerves, or in removing 
 the physical causes which produce these symptoms ? 
 Do oppressed breathing and collection of phlegm 
 arise from an affection of the nerves, or from a 
 condition of the system incompatible with the free 
 circulation and oxygenation of the blood? The 
 reason that galvanism is injurious in those cases 
 of habitual asthma characterised by a tendency 
 to inflammation, is, that inflammation is itself 
 an over-excited state of the capillary vessels of 
 the affected part ; and if we apply this agent, it 
 excites still more, according to its universal in- 
 fluence, and therefore will augment the disease, 
 It is beneficial in cases of congestion, because it 
 stimulates the vessels engorged, and enables 
 them to overcome the burden by which they 
 are oppressed. 
 
 LXXIV. This explanation does not prove the 
 identity of the nervous and galvanic power, be- 
 cause the office of the eighth pair of nerves is 
 
 * Ibid. 525. 
 F 2 
 
8i THE LAWS OF ORGANIC 
 
 not to operate upon the blood in the same way 
 as the aura which is furnished by the pile, but to 
 regulate the respiratory functions, whose busi- 
 ness it is to exercise a more extended influence 
 upon the qualifies of the sanguineous fluid and 
 its mode of circulation ; and as long as these cir- 
 cumstances are attended to, whether by the nor- 
 mal action of the nerves, or the stimulus of gal- 
 vanism, the stomach will continue to secrete gas- 
 tric juice; nor does the explanation compel us 
 to look out for some other mysterious agent 
 whereby w r e shall be enabled to give reasons, 
 why these apparently complicated functions are 
 performed during the absence of their proper in- 
 struments. We shall now pass to another infe- 
 rence, No. 24. ; and after critically examining its 
 merits, we shall be better prepared to judge of 
 the correctness of those principles promulgated 
 by this physiologist, and the reader will then 
 perceive more clearly the value of others which 
 are substituted in their place : 
 
 te That lessening the extent of the nervous si/s- 
 tem, by destroying' the influence of any considerable 
 part either of the brain or spinal marrow, deranges 
 the secreting power" * 
 
 LXXV. WILSON PHILIP having proved that 
 digestion is destroyed when the eighth pair of 
 nerves are divided, was desirous of ascertaining 
 
 * Dr WILSON PHILIP on the Vital Functions, 247. 
 
AND ANIMAL LIFE. 85 
 
 Whether the same effect would follow the partial 
 destruction of the spine, as he believed the sto- 
 mach to receive nerves from this as well as from 
 the brain. To place the question beyond doubt 
 the following experiments were performed, 58, 
 59, 60, 61, 62. As 58. contains few particulars, 
 we shall pass to the next. 
 
 In a full groAvn rabbit a small wire was intro- 
 duced into the spine at the fourth lumbar verte- 
 bra, by which the spinal marrow was destroyed 
 as far as the lowest dorsal vertebra. " Respira- 
 tion was a little disordered. In a short time af- 
 ter the operation, the animal appeared lively, and 
 ate some parsley. The respiration continued to 
 be slightly affected. Some hours after the ope- 
 ration, Mr Hastings, who watched the animal, 
 observed it to be very cold, and it shivered, al- 
 though it was Itept in the same temperature with 
 other rabbits, who shewed no signs of being 
 cold. The rabbit used in the last experiment, 
 58, also seemed cold, but not in the same degree. 
 The respiration now seemed much disordered, and 
 the animal refused parsley. It died in 27 hours 
 after the operation."* After death the follow- 
 ing appearances presented themselves : " The 
 stomach was not much distended. The parsley 
 near the cardiac orifice was not at all changed, 
 and that near the pyloric orifice very slightly. 
 The membrane of the trachea and bronchia was 
 
 * Ibid. p. 172. 
 
86 THE LAWS OF ORGANIC 
 
 more vascular than natural. The bronchial cells 
 were slightly loaded with frothy mucus, and 
 there were the same red patches in the lungs as 
 after dividing the eighth pair of nerves." From 
 bringing forward the symptoms as described by 
 WILSON PHILIP, it is scarcely necessary to make 
 any observations upon them : they differ little 
 from those which have been already detailed, 
 and the results are of the same kind. 
 
 LXXVI. Disordered respiration is one of the 
 first symptoms which he mentions, and this con- 
 tinued for many hours. The animal was lastly 
 observed to be very cold and shivered, which sign 
 has been stated in LXIV. of thepresent Chapter to 
 be the most sure indication of a condition of the 
 system incompatible with the essential functions 
 of life. The cause of the cold which it experi- 
 enced is found in the description which is given, 
 " the bronchial cells were slightly loaded with frothy 
 and bloody mucus." Experiment 60. will illus- 
 trate more accurately the precise states of the 
 temperature. In this experiment he wished to 
 try the effects of the destruction of a smaller por- 
 tion of the spinal marrow, and, for this purpose, 
 introduced a small wire into the spinal canal, at 
 the first lumbar vertebra, " and that part of the 
 spinal marrow which lies below this vertebra was 
 destroyed." The state of the respiration is not 
 mentioned, and from this, one is led to suppose 
 that there was nothing peculiar about it. " On 
 
AND ANIMAL LIFE. 87 
 
 examining it after death, the stomach was found 
 no larger than natural ; the parsley retained its 
 colour, smell, and fibrous texture, although such 
 a change had taken place in it as demonstrated a 
 very slight degree of the digestive process." 
 
 It is to be regretted that few particulars are 
 given concerning this rabbit. We are told that 
 in 35 hours after the operation the animal died ; 
 but the cause of this is not stated. The most 
 important contribution in the experiments at 
 which we have glanced is a table, in the present 
 one, of the temperature of the animal at different 
 times. From inspecting this, and attending to 
 the observations which accompany it, I cannot 
 but flatter myself that the views which I have 
 endeavoured to establish in this and the preced- 
 ing chapters, receive a more correct corroboration 
 than they possibly can from reasoning founded on 
 general facts. Its importance precludes the ne- 
 cessity of apologizing for its insertion. 
 
 " The bulb of Fahrenheit^ thermometer introduced in- 
 to the mouth, and kept there for two minutes previous to 
 the experiment, stood at 98. 
 
 Immediately after the operation, Therm. - 98* 
 In twelve minutes after it, - 92 
 
 In half an hour after it, - 92 
 
 In two hours and a half after it, 98 
 
 In five hours and three quarters after it, - 98 
 In seven hours and a quarter after it, 98 
 
 In nine hours after it, - 96 
 
 In ten hours after it, - 95 
 
88 THE LAWS OF ORGANIC 
 
 The animal during all this time appeared lively, and ate 
 parsley. 
 
 In eleven after it, - - 96 > 
 
 In twelve hours, - 97 
 
 Night coming on, the temperature was not measured for' 
 thirteen hours. In the morning the rabbit appeared lively, 
 and ate readily. 
 
 In twenty five hours after the operation, - 88 
 
 In twenty -seven hours after it, 84 
 
 In twenty -nine hours after it, - 88 
 
 In thirty hours after it, - 84 
 
 In thirty-one hours after it, 84 
 
 In thirty- three hours after it, '* - 80 
 
 The animal still continued to eat. In thirty-four hour? 
 after the operation the temperature was 75." 
 
 " This animal did not appear nearly so cold as 
 that in the preceding experiment, in which a 
 larger and more important part of the spinal 
 marrow was destroyed." 
 
 It is difficult to conceive how so acute a phy- 
 siologist as WILSON PHILIP could watch the di- 
 minution of temperature, the laborious breathing, 
 nay, even the shiverings of the animal, and yet 
 keep his attention fixed exclusively upon the sto- 
 mach and the nerves. This fact ought to make us 
 extremely lenient towards those less gifted, and 
 possessing fewer opportunities of observation. 
 When the temperature of the human constitu- 
 tion is raised or depressed a few degrees, the se- 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 176. 
 
AND ANIMAL LIFE. 89 
 
 cretory organs are invariably deranged, at times 
 almost suppressed, and although there may be a 
 difference in the delicacy of organic functions 
 in the higher and lower gradations of the animal 
 creation, yet, when we perceive the temperature 
 of a being, perhaps not less sensibly constituted 
 than ourselves, from 15 to 23 degrees beneath its 
 natural standard, have we a right, as observers of 
 cause and effect, to anticipate ordinary conse- 
 quences ? In the whole class of hibernating 
 animals, whose peculiarity it is to dose away a 
 third or fourth part of their existence at a pe- 
 riod of the year when their necessities could not 
 be supplied, the feelings which prompt them to 
 look out for food weaken with the diminution 
 of their temperature ; and as these feelings, in 
 health, are proportionate to the activity of inter- 
 nal functions, it is manifest that the influence of 
 cold, whether arising from external or internal 
 conditions, has a regularity in its action, and a 
 uniformity in its effects. The nature of my ex- 
 periments compelled me to keep a great number 
 of rabbits, and the necessity of passing many 
 hours a-day among them, readily disposed me to 
 investigate their habits, and to consider the agen- 
 cy of general causes upon their economy or sys- 
 tem, such as heat, cold, and perturbations of the 
 mind. Whenever the heat was increased by a 
 change in the seasons, or by additional warmth 
 in the room, the animals became more lively, 
 
90 THE LAWS OP ORGANIC 
 
 their appearance in the space of a week or a fort- 
 night more vigorous and sleek but, as soon as 
 the thermometer, in the situation in which they 
 were placed, was as low as 35 or 40 degrees, they 
 presented marked alterations. They crept along 
 as if afraid to expose a large surface of the body 
 to the cold, the sleekness vanished, and the 
 spine soon shewed an unusual prominence, and, 
 when these signs were evident a nightly morta- 
 lity lessened the stock. For some time I attri- 
 buted their haggard and consumptive aspect 
 to disease ; but after reflecting on the influence 
 of cold in modifying the qualities of the blood 
 and its distribution, I was naturally led to 
 regard the assimilative powers of the system 
 as affected by these changes ; and, believing 
 this opinion to be correct, I endeavoured to 
 obviate former consequences by the application 
 of principles deduced from the consideration of 
 their cause. When the days in winter were par- 
 ticularly severe, I placed the young and sickly 
 in a large box kept in the room with the others ; 
 and, by pursuing this plan, I preserved their 
 number and increased their vigour. It is scarce- 
 ly possible to convey an idea of the difference I 
 perceived, in point of liveliness and health, be- 
 tween those subject to a temperature of 75 in a 
 confined place, and those exposed to 35 or 40 
 in a small room. 
 
 I have not made any experiments on the most 
 
AND ANIMAL LIFE, 91 
 
 sickly rabbits, for the purpose of ascertaining the 
 variations of temperature from the state of health ; 
 but among the great number which I have exa- 
 mined, in which some were strong, and others 
 weakly, I have seldom found a difference beyond 
 5 or 6 ; but if this diminution of temperature 
 produces such marked results, can we expect a 
 rabbit to digest its food when constrained and 
 tortured by the experimenter, with laborious and 
 irregular breathing, and a loss of 15 or 20 of 
 animal heat ? If this fact can be established, the 
 secretion of gastric juice is regulated by a partial 
 or individual law a law which is independent 
 of those great principles of the system, and of 
 every modification which these suffer from inter- 
 nal or external general causes. 
 
 The last inference and experiment which I 
 shall at present notice, are the following " That 
 dividing the spinal marrow does not derange the 
 secreting power." To prove this, the spinal mar- 
 row was divided about the middle. " The rab- 
 bit seemed lively after the operation, and conti- 
 nued to eat frequently till within six hours of its 
 death. It died in twenty-seven hours and a half 
 after the division of the spinal marrow. It had 
 not vomited, and had little or no dyspnoea"* In 
 this experiment the digestive power was little, 
 if at all, affected ; and this is just what we should 
 anticipate from the symptoms which he describes, 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 180. 
 
92 THE LAWS OF ORGANIC 
 
 as these show that the respiratory function was 
 scarcely at all troubled. He remarks, " It had 
 not vomited, and had had little or no dyspnoea. The 
 lungs collapsed on opening the thorax, but contain- 
 ed only a little frothy mucus:' If the reader will 
 compare this description with those previously 
 given, he will acknowledge the present experi- 
 ment to be corroborative of the opinion continu- 
 ally expressed concerning the cause of the cessa- 
 tion of digestion. WILSON PHILIP, in speaking 
 of the dark red patches, which always characte- 
 rised the lungs of those rabbits in which the 
 eighth pair of nerves had been divided, observes, 
 that he cannot compare these patches to any 
 thing except what " now and then appears in 
 the lungs of the entire animal after it has lain 
 dead for many hours. In the living animal it 
 was always proportioned to the degree in which 
 the secreting power of the lungs was deranged, 
 appearing to the greatest degree when the conges- 
 tion of the lungs was greatest ; and not appearing 
 at all, although the eighth pair of nerves had 
 been divided, when the breathing was rendered 
 free, and the congestion prevented, by galva- 
 nism."* 
 
 LXXVII. Many fallacies in reasoning are con- 
 cealed by an ingenious or sparing application of 
 principles. The view presented seems correct, 
 because one phase is alone offered, and this of a 
 
 * Dr WILSON PHILIP on the Vital Functions, p. 216. 
 
AND ANIMAL LIFE. 93 
 
 specious description ; but when the application 
 of these principles becomes general, or when it 
 is pushed to the extreme, the variety and promi- 
 nence of objects immediately expose their in- 
 efficiency or incorrectness ; and 1 regret to say, 
 that the principles which we have examined in 
 this chapter, are an illustration of the opinion. 
 
 LXXVIII. Secretion, agreeably to the doctrine 
 of WILSON PHILIP, depends on the operation of 
 the nervous power. " To this (he says) it may 
 be objected, that plants and the less perfect ani- 
 mals have no nervous system. Would it not be 
 more correct to say, that the operation of their 
 nervous system is more confined ? Wherever se- 
 cretion is performed, the nervous influence, or a 
 power resembling it, must exist."* 
 
 That the phenomena belonging to secretion 
 are attributable to nervous influence, or a power 
 resembling it, is a gratuitous assumption. It has 
 never been proved that plants are endowed with 
 nerves ; and yet we perceive that they are cap- 
 able of affecting the air in much the same man- 
 ner as animals ; they have an ascending and de- 
 scending circulation ; they have radicles which 
 select and absorb what is beneficial to their 
 growth ; and the leaves which they possess ope- 
 rate as lungs on the materials conveyed ; and these, 
 after proper elaboration, are appropriated to the 
 various systems of the vegetable, which, in their 
 
 Ibid. p. 258. 
 
94 THE LAWS OF ORGANIC 
 
 turn, are exercised for the growth and support of 
 organic life. 
 
 LXXIX. In those beings which constitute the 
 links between animal and vegetable existence, 
 no nervous system has been detected ; and yet, 
 from the more complex actions which these ex- 
 hibit, it is reasonable to suppose, if such, or si- 
 milar actions, in a more perfect organization, are 
 invariably connected with or produced by nerves, 
 that a nervous system ought to exist. The ab^ 
 sence of such parts ought to teach the physiolo- 
 gist to investigate minutely the systems of those 
 individuals who exhibit only the first rudiments 
 of vegetable and animal life ; and if these have an 
 operation or design analogous to the systems 
 of those whose functions are more extensive, 
 whose relations are more numerous, and whose 
 susceptibilities are greater, he must not measure 
 the laws of the former by his indefinite ideas or 
 principles derived from the latter. If he does, 
 the consequence will be, that the systems of 
 the former will remain unknown, and his know- 
 ledge of those of the latter will be confused or 
 uncertain. 
 
 Abbe HAUY, by taking a crystal, and chipping 
 it, was enabled to discriminate the form of its 
 original nucleus or constitution ; but to detect 
 the important laws of the animal creation, we 
 must not commence by removing the many ad- 
 ditions which have been bestowed and multipli- 
 
AND ANIMAL LIFE. 95 
 
 ed for the adaptations, purposes, and circum- 
 stances of life, but must commence where the 
 crystallographist terminates; and, by attending 
 to this plan, we shall unravel the principles of more 
 perfect systems, which are concealed by parts of 
 secondary formation or importance, scarcely at 
 all essential to the exercise of these principles. 
 
 LXXX. As it may justly be asserted that our 
 senses do not allow us to penetrate deeply into 
 the structure of organized beings, and, therefore, 
 we have no right to deny what we cannot de- 
 monstrate, we will leave plants and imperfect 
 animals, and examine the merits of the doctrine 
 in a manner altogether unexceptionable. 
 
 LX.XXI. A few cases are on record in which 
 foetuses were born without brain or spinal mar- 
 row ; and yet these possessed external endow- 
 ments characteristic of the activity of internal 
 functions ; indeed there was no observable dif- 
 ference between such and others in whom these 
 organs are entire. 
 
 LXXXII. The difficulty which this case pre- 
 sents being insurmountable according to the 
 principles laid down by this physiologist, he 
 says, " No writer, as far as I know, has attempt- 
 ed to explain the difficulty." He confesses that 
 his experiments do not explain it ; but he pro- 
 poses the following view : " If the nervous sys- 
 tem be galvanism, there may be some apparatus 
 in the uterine system for collecting and applying 
 
96 THE LAWS OF ORGANIC 
 
 this agent, which is every where diffused, till the 
 brain and spinal marrow can perform their func- 
 tions, and which may continue to supply their 
 place where they never exist."* Throughout 
 this chapter I have endeavoured to show that it 
 is to alterations in the mode of circulation, or in 
 the qualities of the blood, that the different phe- 
 nomena of the digestive process must be attribut- 
 ed ; and, still farther, that all secretions depend on 
 the sanguiferous system for the extent and acti- 
 vity of their functions : and this reasoning, al- 
 though opposed to the generally received princi- 
 ples, was found to be supported by the disorders 
 induced in the respiration and circulation, and in 
 the evident disease or derangement of the lungs, 
 in all the experiments brought forward. 
 
 LXXX1II. The division which BICHAT has 
 supported of animal and organic life does not apply 
 strictly to the foetus. It does not require a sys- 
 tem of nerves to elevate or depress the ribs, to give 
 motion and sensibility to the body, so that it may 
 be locomotive or taught by its sensations to pre- 
 serve itself; and as the senses are shut from the ex- 
 ternal world, the brain is unessential to its present 
 situation. It, therefore, possesses chiefly organic 
 life ; and at this period, although complex and 
 varied in its organization, it is almost as uncom- 
 pounded as a vegetable, and regulated by nearly 
 similar laws. The difference between the foetus 
 * Dr WILSON PHILIP on the Vital Functions, p. 241. 
 
AND ANIMAL LIFE. 97 
 
 and new-born infant is great. The latter is bring- 
 ing into play, by the exercise of its limbs, and 
 the stimulus of external objects, the endowments 
 of the nervous system, while the former has no ne- 
 cessity for them. But there is no difference what- 
 ever between the foetus and the infant in regard 
 to those systems by which an animal is nourish- 
 ed. One is supplied with arterial blood from its 
 mother, and this is distributed to every part of 
 the body ; the vital principles of which it is com- 
 posed are appropriated to the increase of the em- 
 bryo parts precisely in the same manner as when 
 these parts are subsequently developed and main- 
 tained by blood elaborated by its own organs. 
 The nervous system is as little related in after 
 life as at that time to those peculiar adaptations 
 by which one general fluid is converted into the 
 varieties which the constitution exhibits. It will 
 produce modifications, because it supplies sensi- 
 bility and motion, whose influence is extensive 
 and multiplex. 
 
 LXXXIV. It is therefore obvious, that the dif- 
 ficulty, of which WILSON PHILIP speaks, is a diffi- 
 culty only according to his own principles. The 
 solution which is here given is not derived from 
 hypothetical sources, but is furnished by the same 
 reasoning and observations which have enabled 
 us to expose evident inaccuracies in the views 
 which he has developed, as explanatory of the 
 process of digestion and the generation of animal 
 heat. G 
 
98 THE LAWS OF ORGANIC 
 
 CHAP. IV. 
 
 The ^Distribution of the Blood at different Ages and 
 Seasons. 
 
 LXXXV. WE have been long accustomed to 
 regard the circulation of the blood as composed 
 of an arterial and of a venous system, continually 
 in action ; but our attention has never yet been 
 sufficiently awakened to investigate the import- 
 ant alterations of which these systems are sus- 
 ceptible. The lungs and the heart commence 
 their functions at birth, and as long as life con- 
 tinues they perform the designs of Nature ; but 
 these designs and effects are variable, because the 
 necessities of the system change with the evolu- 
 tion of new, or the feebleness and imperfection of 
 old organs. The lungs unceasingly act upon the 
 blood, and the heart every moment conspires to 
 propel it ; but the former do not always pos- 
 sess the same capability, nor does the latter ex- 
 hibit the same energy through the different stages 
 of existence. If then the qualities of the blood 
 are modified by the different conditions of organ- 
 ization, and if its propulsion and circulation are 
 also subject to the same, is it philosophical to 
 suppose that its distribution will be equable or 
 uniform ? 
 
AND ANIMAL LIFE. 99 
 
 LXXXVI. In physics an effect is proportion- 
 ate to its cause, and the same holds good in the 
 animal frame in regard to all actions that are re- 
 ferrible to this department of science. If a ball 
 be thrown from the hand with great force, it will 
 overcome many obstacles which would retard the 
 course of another propelled with less energy ; but 
 suppose this ball to be thrown through a given 
 space where there are different objects presenting 
 different degrees of attraction or controlling powers, 
 and then we have an idea of the office of the 
 heart and the influence of certain organs in regu- 
 lating or restraining the diffusion of the sangui- 
 neous fluid. 
 
 LXXXVIL Physiologists and Anatomists 
 have long been occupied with the minute struc- 
 ture of the heart and lungs, endeavouring to un- 
 fold their ultimate tissues, to describe the courses 
 or uses of vessels, or the number of nerves which 
 enter into their composition ; and these investi- 
 gations have been productive of many theories 
 and fanciful opinions, which, if true, would have 
 led to no application, but have given rise to one 
 consequence, which has perhaps tended more 
 than all others to mystify the operations of Na- 
 ture, I allude to the study of minute objects. 
 While the mind and the eye have been equally 
 on the stretch to understand and perceive the na- 
 ture of ultimate principles, they have almost en- 
 tirely forgot to observe and examine phenomena 
 
 G2 
 
100 THE LAWS OF ORGANIC 
 
 which are more obvious in their character, and 
 more easily traced. In the attempt to explain 
 the difficulties of the present subject, which, as 
 yet, has never been investigated, I may probably 
 fail in convincing all of the correctness of the 
 views ; but it cannot be denied that the applica- 
 tion is practical. 
 
 LXXXVIII. In the first months of infantile 
 life, the respirations are extremely numerous, pre- 
 senting from 30 to 50 inspirations in a minute ; 
 the heart is also proportionately quick and fre- 
 quent in its pulsation ; and the heat of the body 
 is generally above the standard of the adult. 
 
 LXXXIX. The nourishment of the infant is 
 derived from the breasts of the mother, and this 
 is of a rich and nutritious quality, well adapted 
 to support and extend the powers of life, without 
 requiring much elaboration on the part of its 
 organs to fit it for the purposes of nature. The 
 digestive process, which brings into action the 
 greater part of the abdominal viscera, is, therefore, 
 on the present occasion, not so energetically exer- 
 cised as to make great demands upon the blood. 
 
 And if it be acknowledged that the assimilat- 
 ing organs are less powerfully exercised than 
 in after life, the brain, and those parts of the 
 system subsequently developed for the procrea- 
 tion of the species, are to be considered as influ- 
 encing even less the mode of circulation or the ex- 
 penditure of the blood. Although the former 
 
AND ANIMAL LIFE. 101 
 
 is more perfectly formed at this period than the 
 latter, because more early brought into requisi- 
 tion, yet it is manifest, that, for some time after 
 birth, its action is too feeble to constitute an 
 expensive function of the system. 
 
 XC. It may probably be advanced against 
 the present argument, that the rapid progress of 
 the infant, evinced in the expansion of the body, 
 demonstrates that the functions appropriated 
 to organic life are more active than those of the 
 adult. This idea seems plausible at the first 
 glance ; but if it be remembered that the child 
 is subject to little or no exertion ; that its waking 
 and sleeping moments are unruffled by real or 
 imaginary evils ; that its digestive powers are 
 not deranged by the improprieties of habit, or 
 the influence of moral causes ; and, lastly, that 
 its existence may be said to be distributed into 
 three parts, two of which are devoted to sleep, 
 or a state equivalent to it, and the other to the 
 breast, it will then appear obvious, that this 
 effect does not require superior internal energy 
 on the part of the assimilating organs to give an 
 efficient reason for its occurrence. 
 
 XCL The embonpoint of the system in adults 
 depends less on the quantity or quality of 
 food than is generally imagined. Rest, peace of 
 mind, and a moderate indulgence of our passions, 
 are the principal agents which contribute to pro- 
 duce this result. Indeed the more nearly we 
 
102 THE LAWS OF ORGANIC 
 
 approximate to the life of the infant, the more 
 closely will our frame resemble the form and 
 softness of the infantile system. 
 
 XCIL The frequent respiration of the in- 
 fant explains the quick and numerous contrac- 
 tions of the heart ; and the existence of these 
 conditions, the internal organs being compara- 
 tively inactive, proves that the blood must be 
 more generally and equally distributed to every 
 part of the system. At this age, the circulation, 
 in contradistinction to what subsequently occurs, 
 may be called external ; and, from views which 1 
 intend in the next chapter to unfold, it will be 
 obvious, that this character of the circulation be- 
 longs to the young of every kind ; and, still 
 further, the knowledge of this peculiarity will 
 teach us to estimate the influence of external 
 causes in augmenting or diminishing the gene- 
 ration of animal heat. 
 
 XCIII. As soon as the infant ceases to be 
 dependent on the mother for its support, the 
 digestive functions acquire a greater energy ; 
 and the consequence of this change is, that the 
 stomach, liver, and the whole of the intestines, 
 as well as the excretory organs, make a continual 
 and more extensive demand upon the properties 
 of the blood, and necessarily must modify the 
 previous circulation of this fluid, as these inter- 
 nal actions must be regarded in the light of 
 attractive or controlling powers. In accordance 
 
AND ANIMAL LIFE. 103 
 
 with what is here advanced, it is observed, that 
 the respiration is less frequent, and the contrac- 
 tions of the heart less numerous, as we proceed 
 from infancy to maturity ; and the power of 
 bearing cold is augmented in extent propor- 
 tionate to these changes, not because the power 
 of generating heat is increased, as supposed by 
 Dr EDWARDS of Paris, but because the agency 
 of external causes have not the same states of the 
 circulatory system to influence, 
 
 XCIV. In tracing the infant a little* fur- 
 ther in its progress; we perceive the gradual 
 development of animal life, and the more vigor- 
 ous exercise of those parts belonging to the 
 organic. The mind is not only susceptible to 
 impressions, but is anxious to cultivate a know-* 
 ledge of the various objects by which it is sur- 
 rounded ; and the different sports of this age are 
 calculated to give strength and agility to the 
 body, acuteness to the senses, and vigour to the 
 assimilating functions. 
 
 XCV. In harmony with what I stated in 
 xc. and xci. the child loses, as it approaches 
 the teens, that chubby fulness which charac- 
 terised its earlier years, shewing that this con- 
 dition was not to be referred to the activity 
 of the digestive process, but to the sluggishness 
 of mental and physical powers which are sub- 
 sequently brought into action. Without dwell- 
 ing any longer on gradations of the system, that 
 
104 THE LAWS OF ORGANIC 
 
 will not be fully appreciated by all, we will at 
 once commence to treat of a period of life which 
 developes the distinctive characters of sex. 
 
 XCVI. I have already pointed out in 
 what manner the internal or vital organs of the 
 system influence the circulation of the blood, 
 viz. by their increased importance and energy ; 
 and when these have, for some time, given a 
 different inclination to the distribution of this 
 fluid, the various organs appropriated to the 
 animal propensities appear as additional stimuli 
 or powers to complete that inclination. 
 
 XCVII. The development of these parts, 
 in relation to the blood which must supply them, 
 cannot be considered in the light of a simple in- 
 crease of matter requiring nerves and blood- 
 vessels for their nourishment, but must be re- 
 garded as bringing into play new and essential 
 functions, endowed with principles independent 
 of the general laws of the system, except in so 
 far as these contribute to their wants. 
 
 XCVIII. All secretions of the system are 
 accomplished by certain organs or adaptations, in a 
 way unknown to us, but at all times at the ex- 
 pence of the sanguineous fluid, and they always 
 bear a ratio to the quantity they receive in the 
 state of health. It is therefore evident, that, if 
 we augment the secretions, and particularly such 
 as are not intended for the support of the consti- 
 tution, we must diminish the proportions previ- 
 
AND ANIMAL LIFE. 105 
 
 ously distributed to the different organs, and these 
 proportions will be disturbed according to the 
 exercise or energy of the individual functions in 
 question. 
 
 XCIX. The organs that are late of being deve- 
 loped, when perfectly formed, never cease to make 
 regular demands upon the blood; indeed their of- 
 fice is as constant as that of digestion, till the decay 
 of the natural powers of life, although the pur- 
 pose for which they were intended be not con- 
 summated. If there be any difference between 
 them and other organs, it is that they are sub- 
 ject to occasional and periodical changes, which 
 tend more than any thing I have yet mentioned 
 to give an internal distribution to the blood. 
 
 C. The natural excitation of an internal 
 viscus produces the same local alterations that 
 the morbidly-excited action of any part of the 
 system occasions in the condition of its organiza- 
 tion ; we have in both increased action and a 
 highly vascular appearance ; the striking dissi- 
 milarity between them is in the consequences 
 which succeed. The disorders of the one subside 
 with the cause which gave them rise, but those of 
 the other are followed by febrile symptoms, a 
 derangement of other viscera, and sometimes with 
 disease of its own structure. From this general 
 view of the changes which are peculiar to the 
 animal economy at a certain period of life, it must 
 be obvious to the reflecting mind, that these 
 
106 THE LAWS OF ORGANIC 
 
 changes will lessen the distribution of blood upon 
 the surface of the body, because the internal ne- 
 cessities are great, and therefore we shall have, 
 from this time till the destruction of [organic ex- 
 istence, a state of circulation which may be 
 designated, in contra-distinction to the former, 
 internal. 
 
 CI. At this period of life, approaching to 
 its acme, the respiration has become slow, the 
 contractions of the heart less frequent by almost 
 one half, the animal temperature on the whole 
 less, and the appearance of the body is at variance 
 with those indications which the infantile frame 
 exhibited. We have now the thoughtful, pale, 
 or sallow countenance : if not constitutionally in- 
 corporated, it occurs too frequently not to be 
 remarked, and it is accompanied by too many 
 internal derangements not to be felt, or traced to 
 its appropriate source. But we have not only 
 derangements, but diseases that demonstrate more 
 clearly the correctness of the division of circula- 
 tion at these different states of life, into external 
 and internal. But, before we treat of these, we 
 may advert to the exercise of the mental facul- 
 ties, and the influence which they possess in con- 
 trolling the sanguiferous system. 
 
 CII. The sports, pursuits, or feelings of the 
 child, may be regarded as a general class of exci- 
 tants : they are either attended by muscular ex- 
 ertion, which is favourable to the oxygenation of 
 
AND ANIMAL LIFE. 10? 
 
 the blood arid its general diffusion, or they are 
 characterized by the buoyant or highly stimulat- 
 ing sensations of the mind, which accelerate the 
 function of respiration, or at least tend to main- 
 tain it in an equable and vigorous condition. 
 The child is subject to griefs, but the expression 
 of these is not indicated by thoughtful tacitur- 
 nity, by retirement from ordinary amusements, 
 or by those deep inspirations which deteriorate the 
 properties of the vital fluid at a later period of 
 life, but are indicated by those very acts which 
 tend, even more than its usual sports and feel- 
 ings, to diffuse new life and energy throughout 
 its system, and to maintain that external circula- 
 tion of which we have spoken. 
 
 CIII. The influence of the mind in the child 
 is almost invariably beneficial to its constitutional 
 necessities, while the agency or exercise of this 
 principle is too often injurious in its effects at a 
 later period. The cultivation of intellect, inde- 
 pendently of the mortifications and disappoint, 
 ments almost inseparable from it, is pursued at 
 the expense of many moments that would be bet- 
 ter devoted to sleep or amusement ; but even 
 if we suppose the mind to be passive from the 
 indolence of its possessor, it is still necessarily 
 exposed to a variety of sensations that are disa- 
 greeable or painful, and the universal tendency 
 of these is to bring the blood from the surface of 
 
108 THE LAWS OF ORGANIC 
 
 the body, to surcharge the internal organs, and 
 thus to impede the proper changes of the blood 
 and its dependent functions. Whenever the mind 
 acts to this extent, a morbid congestion or disease 
 of internal parts occurs ; but if the cause which 
 operates be much milder in its consequences, it 
 is still liable to influence the natural internal 
 determination or circulation of blood ; I say na- 
 tural, because I have already shown, that, as 
 we recede from infancy to manhood, the digestive 
 and excretory functions augment, and others which 
 are of Importance to the animal economy are deve- 
 loped and brought prominently forward, the indi- 
 vidual or collective support of which is derived from 
 the blood ; and therefore this change must modify 
 the previous distribution, by creating new internal 
 wants, and presenting new objects as forces of at- 
 traction or powers of control. 
 
 CIV. If the above view be correct, like all 
 principles which are true it must be capable of 
 application ; and if it be proved that the various 
 diseases to which the different ages are exposed 
 have no relation with the peculiarity of the cir- 
 culation, it will then show that my observations 
 and opinion are inaccurate ; but if it be acknow- 
 ledged that the nature or character of the disease 
 depends upon, or is influenced by this state, an 
 opposite conclusion must be drawn. 
 
 CV. From fourteen to eighteen years of age 
 youth is liable to be affected with epistaxis 
 
AND ANIMAL LIFE. 109 
 
 and at the latter end of this period haemoptysis 
 is not at all uncommon. The former is the con- 
 sequence of a still remaining vascularity of those 
 parts of the body which are most external, and 
 is occasioned by the first disturbance which takes 
 place in the system from a change in the mode 
 of circulation, as indicated by a fulness of the 
 head, and its dependent symptoms, such as dizzi- 
 ness, imperfect vision, troublesome or frightful 
 dreams ; and is also frequently accompanied with 
 irritation of the trachea and bronchia, as proved 
 by an occasional cough. 
 
 CVI. Epistaxis is generally produced by ex- 
 ercise, coughing, speaking, violent passion, and 
 other similar causes. The system being ex- 
 cited by these, a quantity of blood greater than 
 what is natural is determined to the surface of 
 the body, and moreover must be evacuated for the 
 safety or well-being of the animal economy ; and 
 as there is no other mucous membrane of the body 
 equally vascular, and bearing the same relation to 
 this extended surface, the blood flows from the deli- 
 cate net-like membrane of the nostrils. 
 
 CVII. It is not my intention to enforce the 
 correctness of this opinion by enumerating the 
 different kinds of practice found most beneficial 
 in its cure. This will occupy our consideration in 
 a subsequent treatise ; but I may observe, that 
 the means employed, such as bleeding, application 
 of cold and internal refrigerants, are precisely 
 
110 THE LAWS OF ORGANIC 
 
 such as are calculated to destroy the condition 
 of the circulation on which the hemorrhage de- 
 pends. 
 
 CVIII. From sixteen to twenty-five, haemop- 
 tysis is the most frequent ; and it is at this pe- 
 riod that the regular internal circulation begins to 
 establish itself ; and when the frame is so con- 
 stituted as not to admit, without disturbance, this 
 alteration, or when an individual is highly ple- 
 thoric, this phenomenon occurs. It may proba- 
 bly be asked, why does not the system relieve 
 itself as it did in the former instance ? the answer 
 to this is simple, the natural vascularity of the 
 surface of the body no longer exists : it is trans- 
 ferred more particularly to the internal organs ; 
 and whenever this normal modification is excited by 
 any of the causes which promoted the former disease, 
 the demand is made upon the lungs, as being the 
 most vascular, the most delicate, and, from their 
 situation, bearing the nearest relation to those parts 
 which are oppressed, or rather to that state of the 
 circulation which is to predominate till the decline 
 oftife. 
 
 CIX. The sensible and delicately formed frame 
 of the female is protected, to a very great extent, 
 from such disorders. Nature has been extremely 
 provident in preserving this part of the creation 
 from derangements to which her constitution 
 would be unequal. When we are suffering from 
 changes in the mode of circulation, which the 
 
AND ANIMAL LIFE. Ill 
 
 strength of our constitution quickly overcomes, 
 the various organs peculiar to her sex are deve- 
 loped ; and from the organization, and extreme 
 vascularity of these at certain periods, the op- 
 pression of the internal circulation is relieved by 
 an excited action of these organs, often long be- 
 fore their operation is required for the ultimate 
 ends of Nature. We thus perceive, that the vi- 
 gour of the one and the delicacy of the other are 
 secured by different designs : the former by the 
 natural robustness of the frame, and by the sports 
 and pursuits proper to that sex, which tend 
 particularly to maintain a moderately external 
 and uniform condition of the circulation ; and 
 the latter, by the influence of functions that might 
 be called premature in their formation, if we con- 
 sidered only the other purposes which these are 
 intended to fulfil. 
 
 CX. The acute and chronic diseases of both 
 sexes from sixteen to twenty-five, and the vari- 
 ous slight derangements to which the system is 
 exposed, may be alluded to as presenting addi- 
 tional proofs in corroboration of this view. In- 
 flammation of the lungs, or thoracic viscera, is 
 not at all unusual ; but this may be determined 
 at every age of life, and therefore may be said 
 to arise rather from the agency of occasional 
 causes than from any constitutional predisposi- 
 tion. But it is between the above-mentioned 
 periods that consumption is the most common 
 
112 THE LAWS OF ORGANIC 
 
 and fatal ; and unless there were some general 
 character of the system favourable to the pro- 
 duction of the disease, we cannot conceive it pos- 
 sible that one-fourth of the population of Europe 
 should annually die of phthisis, as is stated by Dr 
 YOUNG. The exciting causes in civilized life are 
 numerous ; but unless there were a predisposi- 
 tion on the part of the system to the development 
 of such a malady, these causes would not act so 
 extensively as to occasion the most general and 
 destructive chronic disease to which humanity is 
 subject. The general and local means that have 
 in all ages been found the most beneficial in re- 
 tarding its progress, or the most powerful in ef- 
 fecting a cure, have produced their effects be- 
 cause they have universally been such as tended 
 to equalize the circulation of the blood. Gentle 
 exercise of the body, removal to a more tempe- 
 rate climate, sudorifics, emetics, the warm bath, 
 and warm-aired rooms, friction, and the applica- 
 tion of stimuli to the chest, have been recom- 
 mended, and are allowed to be the most effectual 
 in controlling or removing the affection. The 
 action of these is to overcome the morbid inter- 
 nal distribution of the blood, and, by diffusing 
 it more generally throughout the system, enable 
 the lungs to regain the vigorous exercise of their 
 function. 
 
 CXI. The greater number of the disorders of 
 the female are to be attributed to irregularities 
 
AND ANIMAL LIFE, 113 
 
 in the uterine functions, all of which have the ten- 
 dency to increase the natural internal circulation 
 or determination of blood, giving rise to disorgani- 
 zations of the lungs, weakness of digestion, de- 
 ranged secretions of the abdominal viscera, pal- 
 pitation of the heart, and disturbance of the 
 mental powers. It is not necessary to insist 
 further on the correctness of this opinion, by 
 adducing other illustrations : the minute and 
 efficient investigation will be found, not in any 
 single chapter or view, but in examining the 
 general principles which are proposed, in the 
 variety of aspects which different diseases, seasons, 
 and circumstances present. 
 
 CXIII.If we consider the nature of the diseases 
 which occur after the prime of life, which arise 
 simply from the extension of the same principles 
 that we have traced from youth to maturity, we 
 shall be agreeably surprised to find, that Dr CUL- 
 LEN referred the greater number of these diseases 
 to a venous plethora, depending, as he supposed, 
 on a difference in the proportional density of the 
 coats of the arteries and veins. He imagined 
 that in early life the coats of the veins have a 
 proportional density greater than those of the ar- 
 teries, on which account the plethoric state of the 
 latter is to be regarded as the cause of many con- 
 stitutional derangements and diseases ; but at a 
 subsequent period the density of the coats of the 
 arteries becomes superior to that of the veins, and 
 
 H 
 
114 THE LAWS OF ORGANIC 
 
 we have then a class of diseases called passive 
 Hcemorrhagies. 
 
 CXIV. The effects of this venous plethora of Dr 
 CULLEN are precisely the same that we should 
 anticipate to happen from a knowledge of the 
 general changes in the circulation, as stated in 
 this chapter ; and it is for the reflecting reader to 
 judge, whether the present coincidence ought to 
 be regarded as confirming the views which I 
 have attempted to establish. 
 
 CXV. In old age the motions of the heart are 
 less forcible ; the capillary system of the lungs 
 less vascular ;* and the ability or disposition to 
 exertion is diminished. It is therefore manifest 
 that the blood is propelled with less energy by the 
 influence of its moving powers throughout the 
 system. The properties of the vital fluid are 
 also less stimulating ; and these conditions, com- 
 bined with the comparative inactivity of the 
 body, are well calculated to augment the natural 
 internal determination of the sanguineous fluid. 
 But we are not to suppose that the system in the 
 decline of life contains the same quantity of blood 
 which it did in its prime ; the more confined 
 operation of those organs necessary to digest and 
 
 * En examinant les cellules du poumon, j'ai etc frappe de la 
 variation de grandeur qu'elles eprouvent par les progres de 
 1'age 5 leur nombre est en raison inverse des annees. II resulte 
 de ce fait que notre poumon doit acquerir, a measure que nous 
 vieillissons, une legerete specifique tres grande. Journal de 
 Physiologic Experimentale. Par F. MAGENDIE. 4th Number. 
 October, 1821. /?, 80. 
 
AND ANIMAL LIFE. 115 
 
 assimilate has gradually been diminishing the 
 proportion, to allow the lungs and heart to act 
 with moderate correctness. 
 
 CXVI. From the preceding views we may draw 
 the following conclusions : 
 
 1 . That the blood in all young animals is generally diffused 
 
 through the system, on account of the internal ne- 
 cessities making little demand upon this fluid ; and 
 that the character of this distribution is changed in 
 proportion to the development of these necessities. 
 
 2. That, at the maturity of the animal frame, the internal 
 
 organs are more vigorous than at any other period of 
 life ; and that, as the natural or diseased action of 
 these is augmented, if unaccompanied by fever or ex- 
 ercise, the blood in all cases is determined to them 
 in greater quantity than natural, either maintaining 
 the regular internal circulation, or extending this to a 
 state of aberration. 
 
 3. That, at the decline of the powers of life, the blood is 
 
 more internal in its circulation than at any other 
 period, from the concurrent influence of the pre- 
 vious gradual changes tending to promote this effect, 
 and from the imperfection of those functions essential 
 to renew its qualities and facilitate its motion. 
 
 CXVI I. From these deductions others are to 
 be drawn, the consideration of which will occupy 
 much of our attention. Those which we shall at 
 present consider are the following : 
 
 1. That, if the blood be more equally diffused in infancy 
 throughout the system, it is obvious that a much 
 H 2 
 
116 THE LAWS OF ORGANIC 
 
 greater proportional quantity will be distributed upon 
 the surface of the body at this period of life, and con- 
 sequently a greater quantity will be exposed to the 
 action of heat or cold. 
 
 $. That exercise, and stimuli of every description will pro- 
 duce a factitious condition of the system, in character 
 somewhat similar to that which is natural to the child. 
 
 3. That the general application of heat and cold will be 
 injurious or beneficial according to the distribution 
 of the blood upon the surface of the body and the 
 degree of energy possessed by the internal organs. 
 
 CXV1II. Having premised these general prin- 
 ciples, we shall be enabled to understand the influ- 
 ence of seasons in modifying the distribution of 
 the blood. 
 
 The temperature of summer enlivens the ani- 
 mal and vegetable world, because the organic 
 life of both is regulated by the same physical 
 laws, and heat is as much a stimulus to the gener- 
 ation of motion in the one as in the other, and 
 from motion and warmth spring every change that 
 is necessary to preserve existence or maintain its 
 attributes. 
 
 CXIX. The hibernating animals, and such as 
 retain during the severity of winter the general 
 powers of life, are enabled, by the greater warmth 
 of spring, to resume their different functions. 
 The former are again animated, and the latter, 
 in addition to their present faculties, display, 
 like the plant, an exuberance of life. 
 
AND ANIMAL LIFE. 117 
 
 CXX. The influence of warmth in animals ope- 
 rates upon the surface of the body and the or- 
 gans which are fitted to improve the qualities of 
 the blood. By exciting the surface, the action 
 of the capillaries is universally stimulated ; and 
 the consequence of this is, that the internal or- 
 gans participate in the change, as they are neces- 
 sarily relieved of a portion of blood, from its more 
 equal diffusion, and are rendered more capable of 
 oxygenating, transmitting, and assimilating that 
 which they receive. By acting upon the lungs, a 
 direct stimulus is applied to their capillary ves- 
 sels, which are intimately concerned in effecting 
 the various changes of the blood, and directing the 
 mode of its distribution ; and in so far as these are 
 accomplished, the effects arising from the external 
 cause will be more or less permanently or generally 
 established. If these alterations have taken place, 
 it must be allowed that the nervous system will 
 soon evince a corresponding condition, as the re- 
 sult of these alterations ; and we observe, that 
 whatever depends on motion or sensation, becomes 
 unusually energetic. 
 
 CXXI. Suppose a plant and an animal to have 
 been brought prematurely forward, and after- 
 wards to be exposed to a degree of cold rather 
 severe for the season, they are both influenced 
 in the same way by the same exciting and proxi- 
 mate causes. The surface of both is highly vas- 
 cular ; and as a greater proportional quantity of 
 
118 THE LAWS OF ORGANIC 
 
 fluid is subjected to the action of cold, a greater 
 quantity will be successively acted upon until 
 the minute vessels are constricted by this agent ; 
 and when this happens, the plant droops, and 
 the bird forgets its song. Every phenomenon 
 of organic and animal life is regulated by, or de- 
 pends upon, the nature and motion of the circu- 
 lating fluid peculiar to the individual being. 
 
 CXXII. From this view it appears that summer 
 has the tendency to diffuse the blood in greater 
 quantity over the surface of the body ; and this 
 being the case, an individual will at this time be 
 more liable to internal disorders and inflamma- 
 tions than in the middle of winter, from the occa- 
 sional application of the opposite temperature. 
 It is an ascertained and acknowledged fact, that, 
 in autumn, inflammations of the thoracic viscera, 
 fevers, and dysenteric affections, are more com- 
 mon than at any other season. 
 
 CXXIII. Previous to autumn, the system has 
 experienced a general stimulus : accelerated cir- 
 culation and augmented heat are its consequen- 
 ces ; and as these conditions have existed for a 
 long time, they have, in some measure, become 
 established, and, therefore, cannot be expected to 
 return immediately to another state which is to 
 adapt the animal economy to different circumstan- 
 ces. It sometimes happens that autumn does not 
 approach in a benignant or gentle manner, but, on 
 the contrary, is accompanied by cold and damp 
 
AND ANIMAL LIFE. 119 
 
 nights, unusually severe ; and, whenever this occurs 
 the circulation is taken by surprise, * the blood is 
 suddenly determined to the internal organs, and 
 that which is the most susceptible to the impres- 
 sion becomes the seat of disease. In this way 
 arise the frequent coughs, inflammations of the 
 lungs or bowels, dysenteric symptoms, and fe- 
 vers incident to that season. 
 
 CXXIV. When the constitution has been some 
 time accustomed to the wet and cold days of 
 winter, it is capable of resisting the influence of 
 these with great security. If the system had not 
 undergone a change in the mode of its circula- 
 tion, it is impossible to conceive by what means 
 it could withstand the operation of those causes 
 to which it is exposed, since we observe so much 
 internal disease occasioned by similar, but much 
 weaker agents, in the more temperate seasons. 
 
 CXXV. Dr CURRIE, in treating of the sub- 
 ject of cold affusion in fevers, is correct in the 
 observations which he makes regarding the condi- 
 tions of the system which ought at all times to 
 regulate its employment ; but he does not appear 
 fully acquainted with the principles on which the 
 truth of his observations rests. He remarks, that 
 it may be resorted to with safety and benefit 
 when the temperature of the body is above the 
 
 * Nam fere (autumno) meridianis temporibus calor ; noctur- 
 nis atque matutinis, simulque etiam vespertinis, frigus est, 
 corpus ergo, et aestate, et subinde meridianis caloribus relaxa- 
 tum, subito frigore excipitur.'' CELSUS, Lib. II. Cap, I. 
 
120 THE LAWS OF ORGANIC 
 
 standard, and when the circulation is vigorous, 
 if these symptoms have not been preceded by 
 profuse perspiration or great fatigue. 
 
 CXXVI. The augmented temperature and cir- 
 culation are proofs that the thoracic organs are 
 unusually or morbidly active ; and the great 
 quantity of blood which is distributed upon the 
 surface of the body is sustained there by its 
 highly stimulating properties and the force with 
 which it is propelled. When an individual, with 
 a constitution thus circumstanced, submits to the 
 application of cold, it produces a good effect, as 
 it diminishes the heat of the system and the 
 strength of arterial action, without possessing 
 sufficient influence to oppress the energies of the 
 vital powers. But when the body has been much 
 fatigued, or if it has perspired freely, the appli- 
 cation of the same means is injurious. After 
 fatigue and perspiration the blood is transmitted 
 with less vigour and less stimulating properties 
 to the surface, on account of the diminished ac- 
 tion of the lungs and heart ; and, therefore, if 
 cold be recommended in this state of the system, 
 it will disappoint the expectations of the physi- 
 cian, because it will determine the blood inter- 
 nally, and control still more the weakened function 
 of the lungs and heart, so that the oxygenation and 
 the propulsion of the Hood will be much impeded. 
 
AND ANIMAL LIFE. 121 
 
 CHAP. V, 
 
 Temperature at Different Ages. 
 
 CXXV1I. THE present subject is one of great 
 interest and importance. The principles by which 
 we shall be guided in the investigation are con- 
 nected with those which have been already stated, 
 and will strengthen materially the reasoning pre- 
 viously employed. 
 
 CXXVIII. The temperature of the body at 
 different ages has occupied very much the atten- 
 tion of Dr EDWAUDS of Paris. Indeed, the ex- 
 periments which he performed to elucidate this 
 subject, and the consideration and application of 
 the laws which he deduced from them, compose 
 at least one-third of his work, which is un- 
 doubtedly the best in any language for the mul- 
 tiplicity, variety, and accuracy of experiments ; 
 but these, unless they lead to general laws, or 
 unless they are brought forward to support such, 
 are of little consequence, except in so far as they 
 enable others to think. 
 
 CXXIX. In the chapter on secretion, I have 
 shown how WILSON PHILIP was mistaken in his 
 opinions concerning the dependence of digestion 
 on the eighth pair of nerves, from judging by ef- 
 fects, without taking into account, in any single 
 instance, the general disturbance induced in the 
 
122 THE LAWS OF ORGANIC 
 
 system by such an operation ; and I shall now 
 endeavour to show, that one great error which 
 pervades the work of Dr EDWARDS, concerning 
 animal temperature, is referrible to a similar 
 cause. This gentleman states, that the faculty 
 of producing heat is invariably less in young ani- 
 mals than in adults; and the chief proof which he 
 gives is, that if young and old animals be exposed 
 to the same degree of cold, the temperature of the 
 former almost immediately falls, and continues to 
 do so unless they be removed to a warmer medium, 
 while that of the latter is little if at all affect- 
 ed by the refrigerating influence. This constant 
 result made him conclude, that young animals 
 do not generate an equal quantity of heat, be- 
 cause he supposes, if this were the case, they 
 would both bear with the same facility the ex- 
 posure to cold. From the development of other 
 views, it will be , clear, that they may generate 
 the same proportionate quantity of heat, and yet 
 may be unable to bear the same extent of cold. 
 
 CXXX. Dr EDWARDS took the temperature 
 of 20 adults, and found the medium to be 36. 12 
 centigrade thermometer; and from 10 infants 
 whose temperature was taken in the same way, 
 the medium was found to be 34. 7. In these ex- 
 periments the thermometer was placed in the arm- 
 pit. There are many objections to this mode of 
 ascertaining the degree of animal heat. The part 
 is particularly subject to perspiration, which may 
 modify very much the results ; or if the arm has 
 
AND ANIMAL LIFE. 123 
 
 been removed from the contact of the body it 
 will be cooler than usual, or if it has been long 
 applied to this it will be warmer at one time than 
 another. These circumstances are of sufficient 
 importance to occasion great variations in the in- 
 dications of the thermometer, and consequent 
 fallacies in the reasoning. The plan which I fol- 
 lowed appears to me more correct, but it is cer- 
 tainly very tedious. Mr MOIR, surgeon-accou- 
 cheur to the Lying-in-hospital, Edinburgh, had 
 the kindness to allow me the opportunity of tak- 
 ing the temperature of infants. The temperature 
 of the body was at all times estimated by the in- 
 dications which the thermometer gave in the 
 mouth when the infant was asleep. To make 
 the instrument as delicate as possible, it was dip- 
 ped for a moment before it was employed into a 
 cup of warm water, from 5 to 10 degrees above 
 the animal heat. The bulb being thus slightly 
 warmed, did not awake the infant by its applica- 
 tion, and was made much more sensible than the 
 most delicate thermometer could otherwise have 
 been. The same method was, in the greater 
 number of instances, attended to in taking the 
 temperature of adults. The child would some- 
 times be disturbed, but very rarely, by the intro- 
 duction of the thermometer. Whenever this was 
 the case, the attempt was postponed till the next 
 visit. I have also noted the age of the infant, the 
 number of its respirations, and the state of the 
 constitution. 
 
124 THE LAWS OF ORGANIC 
 
 Days Old. Temp, of the Body. Respiration'per Min. Remarks. 
 
 14 - 99 - 28 '- Weak. 
 
 12 - 101| : 54 - Strong. 
 
 8 - 99 - 30 Ditto. 
 
 7 - 96 - 46 Healthy, 
 
 5 98 - 46 - 7 Ditto. 
 
 8 - 99 - 38 Ditto. 
 
 3 - 94| , 52 Delicate. 
 
 12 - 99 48 -, Healthy. 
 11 - 98 32 '<>*'&> Delicate. 
 
 2 - 100 - 52 Strong. 
 
 4 - 96|. - 48 Weakly. 
 
 2 - 97^ - 48 Healthy. 
 1 - 99 - 32 Ditto. 
 
 9 99 - 44 Ditto. 
 
 7 - 97J - 25 Delicate. 
 
 3 - 97 - 50 Rather delicate. 
 
 1 - 98 - 48 
 
 13 - 99| - 36 - Very stout. 
 
 6 .101 - 30 - Ditto. 
 
 11 - 103| - 42 - Healthy.* 
 
 2 - 100 - 40 Ditto. 
 2 - 99| - 44 Ditto. 
 
 13 - 101 , 46 Stout. 
 
 9 < 100J 44 Very vigorous. 
 
 8 - 99 - 44 Healthy. 
 
 4 99 - 39 Ditto. 
 
 12 - 98| 44 Delicate. 
 8 - 100 48 Healthy. 
 
 10 Months 101 32 Very vigorous, 
 
 8 - 99 - 40 Healthy. 
 1 - 98 
 
 5 - 101 - 48 Healthy. 
 12 - 99 ~ 44 Ditto. 
 
 11 - 102 - 36 r Sickly. 
 
 9 - 95 - 75 f 
 
 18 99i - Healthy 
 
 8 - 100 - Ditto. 
 
 11 - 99 - 32 - Ditto. 
 
 1 , 98| , 55 Ditto, 
 
 8 - 98| - 48 Ditto, 
 Medium Temperature 99. 
 
 * The mother of this child sat close to the fire, but I cannot say whether 
 this was the reason that the temperature was so very high. I tried it twice 
 to be sure of the accuracy of the results. 
 
 f This child seemed remarkably stout, but it was evidently unwell. Its 
 respiration was short and imperfect. 
 
AND ANIMAL LIFE. 125 
 
 The following Table gives the Temperature of the same 
 number of Adults. 
 
 Temp, of the Body, Habits. 
 
 98 - Active. 
 
 95 - Sedentary. 
 98 - Active. 
 97| - Ditto. 
 
 98 - Sedentary. 
 
 97 - Active. 
 100 - Ditto. 
 
 97i - Sedentary. 
 
 99| - Ditto. 
 
 95| - Active. 
 
 99 - Ditto, 
 97 - Ditto. 
 96| Ditto. 
 
 98 - Ditto. 
 95 - Ditto. 
 
 98 - ' Ditto. 
 
 97 - Ditto. 
 97* - Ditto. 
 96| - Ditto. 
 
 96 - Ditto. 
 96 - Ditto. 
 98* - Ditto. 
 97* - Ditto. 
 
 99 - Ditto 
 
 96 - Ditto 
 
 - Ditto. 
 
 - Ditto. 
 
 - Ditto. 
 99 - Ditto. 
 
 98 - Sedentary. 
 
 99 - Ditto. 
 96| Ditto. 
 97* - Ditto. 
 
 97 Ditto. 
 99* - Ditto 
 99| Active. 
 
 98 Ditto. 
 99* Ditto. 
 99 - Ditto. 
 97 Ditto. 
 
 Medium Temperature 97|. 
 
126 THE LAWS OF ORGANIC 
 
 CXXXI. From these tables it is evident that 
 young animals do not indicate a less degree of 
 temperature than adults, if they are examined 
 under circumstances favourable to the sensibility 
 of their frame, or in situations not liable to great 
 changes. It is unnecessary to bring forward the 
 particular details of Dr EDWARDS to shew that 
 young animals bear cold with less facility than 
 adults ; the fact is undoubted, but is not to be 
 explained by supposing the source of generating 
 heat less in the former than in the latter. 
 
 CXXXII. The lungs are to be regarded as 
 the cause of animal temperature. We observe 
 that this is modified very much by the altera- 
 tions which the lungs undergo ; at one time it is 
 much increased, at another equally diminished, by 
 disease or general affections. The manner in 
 which the greater number of these causes oper- 
 ate has been explained in the previous chapters, 
 particularly in the first, in which I endeavoured 
 to shew that animal heat is in the inverse ratio to 
 the quantity of blood exposed to the action of the in- 
 spired air ; and in the preceding chapter on the 
 distribution of the blood at different ages, I have 
 also pointed out the great changes of which this 
 is susceptible, from the increased activity or more 
 complete development of internal organs. 
 
 CXXXIII. The blood in a young animal 
 being more generally diffused throughout the 
 system, the surface of the body, at this time of 
 
AND ANIMAL LIFE. 127 
 
 life, possesses a greater proportional quantity than 
 at a subsequent period. If this be allowed, it is 
 manifest that cold will simultaneously act on a 
 much greater quantity of blood in the child than 
 in the adult ; and as this mode of circulation is na- 
 tural, not determined here by an augmented action 
 of the heart and lungs as in fever, it is perfectly 
 consistent to suppose that a young animal will be 
 cooled, while an old one is not affected, by a mo- 
 derate degree of cold. The child may be said to 
 expose an extended surface of blood to the influence 
 of the external air, while the adult, on the other 
 hand, has the surface of the external circulation re- 
 latively diminished by the more vigorous operation 
 of the different internal organs. 
 
 CXXXIV. The cold to which a young animal 
 is subjected tends almost immediately to constrict 
 the external capillary vessels ; the consequence 
 of which is, that the surface of the body becomes 
 pale, and the animal intimates, by cries or other 
 symptoms, that unpleasant sensations are excited; 
 and, unless we remove the individual to a warmer 
 medium, fatal effects speedily follow. If we ex- 
 amine the indications of the thermometer as these 
 changes proceed, we remark that they are cor- 
 respondingly affected. The blood is driven upon 
 the thoracic and abdominal organs, and destroys, 
 in a short time, the harmonious balance existing 
 between the internal and external circulation of 
 blood. The lungs receiving more than they usu- 
 
128 THE LAWS OF ORGANIC 
 
 ally possess, the additional quantity necessarily 
 impedes the oxygenation and circulation of the 
 blood ; and, in proportion as these essential con- 
 ditions are disturbed, we shall find that the facul- 
 ty of generating animal heat is diminished, because 
 this is more powerfully influenced by the more ge~ 
 neral distribution of the blood in early life, and not 
 that it was originally less, as contended for by Dr 
 EDWARDS. 
 
 CXXXV. To prove the correctness of these 
 principles, we shall examine the various causes 
 which, agreeably to Dr EDWARDS' opinion, mo- 
 dify the generation of animal heat. It is stated 
 by him, that the temperature of animals is capa- 
 ble of being most diminished by the artificial ap- 
 plication of cold in summer, because the power 
 of producing heat is less at this season. 
 
 CXXXVI. Summer produces a character of 
 circulation essentially similar to that peculiar to 
 infancy and childhood. The capillary vessels are 
 not constricted, as in winter, thereby determin- 
 ing the blood within, but are excited to greater 
 action from the application of heat ; therefore the 
 blood is more equally diffused throughout the sys- 
 tem, offering, as in infancy, an increased surface 
 of blood to the action of cold so applied. 
 
 CXXXVII. An animal, in accordance with 
 this explanation, will suffer sooner from the in- 
 fluence of artificial cold in summer than in win- 
 ter ; and this is fully verified by the experiments 
 
AND ANIMAL LIFE. 129 
 
 of Dr EDWARDS, although he assigns lessened 
 production of heat as the cause. The principle 
 I propose immediately becomes of practical uti- 
 lity, whereas those views which have hitherto 
 been given as explanatory of the same phenome- 
 na have indeed little reference to the different 
 states of the system in health or disease. We 
 now understand that young animals have an 
 equal, if not superior faculty of producing heat 
 to adults, and yet, at the same time, have not the 
 power of bearing the same severity of cold. The 
 true reason of this being known, we shall be en- 
 abled to regulate the application of heat and cold 
 to the body, from a knowledge of the principal 
 conditions of the system on which they have to 
 act ; and we shall also be enabled to judge accur- 
 ately of the beneficial or injurious influence of 
 these, from a knowledge of the dependence of the 
 digestive and assimilating functions on the tem- 
 perature of the blood and the mode of its distri- 
 bution. 
 
 CXXXVIII. During the winter of 1828-29, 
 the cold in some nights was extremely severe. The 
 thermometer, in the room in which I kept the 
 rabbits for experiments, was often as low as 37 ; 
 in an apartment adjoining to this water was fro- 
 zen to a considerable thickness. During the 
 continuance of this weather I lost a great num- 
 ber of young rabbits, and the old occasionally 
 died ; and all, except the most vigorous, were far 
 
 I 
 
130 THE LAWS OF ORGANIC 
 
 from having a healthy appearance. I frequently 
 took the temperature of rabbits under a variety 
 of circumstances, and I generally found that the 
 young and the delicate evinced a low degree of 
 heat during the prevalence of cold, while the old 
 exhibited few changes, exposed to the same agent. 
 The difference in the results were attributed 
 to alterations of the circulation ; and believing 
 these to be the cause, I endeavoured, by the fol- 
 lowing experiments, to show that a medium tem- 
 perature, by allowing the blood to diffuse itself 
 more generally upon the surface of the body, 
 would certainly increase the faculty of generating 
 heat, as it relieves the internal organs on which 
 this depends. 
 
 The temperature of twelve rabbits was taken that were 
 equally exposed to cold, 43 ; and the same three days after 
 were kept in a room at 67 for two hours. 
 
 Temp, of 
 
 C I 
 
 
 Room, 43. 
 
 o our. j 
 
 ppea 
 
 2 Months old, 
 
 Black, 
 
 Healthy. 
 
 Ditto, 
 
 Black &. white, 
 
 Ditto, 
 
 Ditto, 
 
 Black, 
 
 Very vigorous, 
 
 Ditto, 
 
 Ditto, 
 
 Small, 
 
 Ditto, 
 
 Ditto, 
 
 Healthy, 
 
 3 Months old, 
 
 Grey, 
 
 Vigorous, 
 
 Old rabbits, 
 
 Black, 
 
 Ditto, 
 
 Ditto, 
 
 Grey and white, 
 
 Ditto, 
 
 Ditto, 
 
 Grey, 
 
 Ditto, 
 
 Ditto, 
 
 Black, 
 
 Very vigorous, 
 
 Ditto, 
 
 White & yellow, 
 
 Vigorous, 
 
 Ditto, 
 
 Yellow, 
 
 Healthy, 
 
 99 102 
 
 99 103 
 
 102 103 
 98 103 
 98 102 
 
 102^ 103 
 
 104 104 
 
 103 
 
 108 
 
 103 105 
 
 103 104 
 
 100 103 
 
AND ANIMAL LIFE. 131 
 
 In the following experiments, instead of bring- 
 ing the rabbits from the room in which they 
 were kept, I confined them in a box, in the same 
 situation, for two hours ; and the results were as 
 follow : 
 
 Temperature of air in room 43. 
 
 Temp. Rabbits Temp. Rabbits 
 
 
 Colour. 
 
 Appearance. 
 
 in Room. 
 
 in Box. 
 
 3 Months old, 
 
 Black &. white, 
 
 Healthy, 
 
 101 
 
 101 
 
 Ditto, 
 
 Grey & white, 
 
 Ditto, 
 
 101 
 
 102$ 
 
 Ditto, 
 
 Black &. white, 
 
 Ditto, 
 
 102 
 
 102 
 
 Ditto, 
 
 Grey 8c white, 
 
 Ditto. 
 
 101 
 
 103 
 
 Ditto, 
 
 Ditto, 
 
 Strong, 
 
 103 
 
 104 
 
 Old Rabbits, 
 
 Grey & white, 
 
 Healthy, 
 
 102 
 
 102 
 
 Ditto, 
 
 Ditto, 
 
 Ditto, 
 
 103| 
 
 103| 
 
 Ditto, 
 
 Ditto, 
 
 Ditto, 
 
 103 
 
 105 
 
 Ditto, 
 
 Grey, 
 
 Fine bock, 
 
 103 
 
 104 
 
 Ditto, 
 
 White. 
 
 White, 
 
 103 
 
 102 
 
 The temperature of the box, in both instances, 
 was 67. In the first experiment, the rabbits 
 that were two months old indicated a rise of four 
 and five degrees in the short space of two hours ; 
 but in the second, in which rabbits of three 
 months old were employed, we observe that the 
 influence of the increased temperature produced 
 less decided effects, because they possess, at this 
 age, a constitution approaching to that of adults. 
 
 CXXXIX, It is stated by Dr EDWARDS, that 
 young rabbits of twelve or fifteen days old, " se 
 soutienne a peu-pres egale a celle des adultes, 
 au-dessus d'une temperature exterieure moy- 
 
 i 2 
 
THE LAWS OF ORGANIC 
 
 enne."* It is evident, from the preceding tables, 
 that rabbits of two and three months old do not 
 bear equally well the severities of winter. I have 
 not only ascertained this fact by direct experiment, 
 but I have observed its correctness, from remark- 
 ing a variety of phenomena connected with these 
 animals. If it be allowed to Dr EDWARDS, that 
 young animals, from birth to the age of fifteen 
 or thirty days, do not possess the faculty of ge- 
 nerating animal heat to a degree equal to adults, 
 how will he consistently explain the difference 
 which we observe between rabbits of three months 
 old and others full grown, on being exposed to 
 cold ? If, at three months, the faculty of generat- 
 ing heat is as perfect as at nine, what is the na- 
 ture of those circumstances which modify the ca- 
 pability of the animal for bearing diminished tem- 
 perature ? These are questions of the greatest im- 
 portance ; but they are not answered by Dr ED- 
 WARDS' views. The explanation is found in the 
 present principles. As we ascend from birth to the 
 full development of the physical powers of the 
 system, the circulation is less generally diffused, 
 or, in other words, the greater proportional quan- 
 tity is given to the internal organs for their support 
 and development. It is, therefore, obvious that 
 an animal will bear cold with a facility, cceteris 
 par 2 to, proportion ate to the extent of this change. 
 CXL. Having shown that the phenomena 
 which animals present in summer, in regard to 
 
 * Dr EDWARDS, p. 1S6, 
 
AND ANIMAL LIFE. 133 
 
 cooling, are easily explained by the present prin- 
 ciple, we shall now pass to several others brought 
 forward by Dr EDWARDS, not in support of his 
 own opinion, but as facts. He states that exte- 
 rior heat supplies the deficiency in the faculty of 
 producing* 
 
 When we apply warmth to the surface of the 
 body, without in the least modifying the tempe- 
 rature of the air we inspire, we augment the ge- 
 neration of animal heat. This effect is not easily 
 perceived when the system is naturally excited, 
 because the difference we can produce in the 
 mode of circulation is too slight to influence, in 
 an appreciable manner, the generation of this 
 principle : but if this be employed when the 
 powers of life are much oppressed by a great de- 
 termination of blood to the internal cavities, 
 the beneficial influence of this agent is strikingly 
 displayed. Physiologists and physicians have 
 long known that such means diminish internal 
 congestion ; but they must have supposed that 
 this was confined chiefly to the abdominal vis- 
 cera, as they appear unacquainted with the ge- 
 neral principles and their application, fully treat- 
 ed of in various parts of this work. Friction, ap- 
 plied to the body, produces similar consequences 
 to those of heat ; and this shows that the action 
 of heat affects the internal production principally 
 by bringing to the surface an additional quantity 
 
 * Dr Ei> WARDS, p. 480. op. citat. 
 
134 THE LAWS OF ORGANIC 
 
 of blood, and thereby lessening the proportion 
 exposed to the air in the lungs, according to the 
 views developed in the first chapter. 
 
 CXLI. The diminution of the temperature of 
 animals is less injurious in very early than in ad- 
 vanced life, because it is found that at the former 
 period they sooner regain their accustomed stand- 
 ard of heat. In speaking of this, Dr EDWARDS ob- 
 serves, "Nous voyons que c'est a mesure que la fa- 
 culte de developper la chaleur s'accroit que la fa- 
 culte de supporter Tabaissement de la temperature 
 du corps diminue."* After these observations, he 
 alludes to the necessity of such a law with respect 
 to those animals which are forced to leave their 
 young in search of food. The necessity of such a 
 provision in the constitution of the young is evi- 
 dent ; but the simple statement of this is no ap- 
 proach towards an explanation of the principles on 
 which it depends. The faculty of bearing a dimi- 
 nution of temperature is not regulated by the con- 
 dition lie states, viz. the power of generating heat. 
 I have already shown, in the previous tables, that 
 infants, in general, have a superior temperature 
 to adults ; and that rabbits vary little, if at all, 
 at different ages, if exposed to a medium tempe- 
 rature. The truth of this I have proved by di- 
 rect experiment ; and therefore it is inadmissible 
 to suppose that young animals suffer less than 
 adults from the action of cold because they ge- 
 
 * Dr EDWARDS, p. 242. 
 
AND ANIMAL LIFE. 135 
 
 nerate less heat, and that the power of bearing 
 cold diminishes because the production of this 
 principle is increased. This must be allowed to 
 be the meaning of Dr EDWARDS, if we agree 
 with him that young animals have an inferior 
 power of evolving caloric. 
 
 CXLII. When a young animal is subjected to 
 cold, it is quickly affected ; the blood is speedily de- 
 termined to the internal organs, and the body shows 
 a great diminution of temperature : but the very 
 conditions which promote this sudden change are 
 those which are favourable to the re-establishment 
 of the normal functions. The surface of the body 
 at this period is naturally vascular, and on this ac- 
 count is more sensible to the application of heat ; 
 and it is this character of the circulation which ex- 
 plains the phenomena connected with the present 
 subject. 
 
 CXLI1I. When the temperature of an adult 
 is much reduced, the system recovers with dif- 
 ficulty the possession of its ordinary powers. 
 The vigorous frame of a full grown animal is not 
 readily controlled or influenced by cold : it con- 
 sequently follows, that if it be oppressed by this 
 agent, its degree must have been severe, or its em- 
 ployment long continued circumstances which 
 we are not compelled to take into consideration 
 in reflecting on the changes which one of tender 
 years presents. 
 
136 THE LAWS OF ORGANIC 
 
 CXLIV. The system of the adult having 
 been thus powerfully acted upon, and the surface 
 of the body being less vascular at this period of 
 life, it cannot be expected that external warmth 
 will immediately solicit the return of the san- 
 guineous fluid ; the degree and continuance of 
 its application must be proportionate to the con- 
 ditions of the cause to produce a beneficial re- 
 sult. 
 
 CXLV. It is demonstrated by experiment, that 
 when an animal has been cooled several times to 
 a point beneath the regular temperature of the 
 body, it becomes more difficult to re-establish 
 the usual degree of heat, and this is what we 
 should have anticipated from a knowledge of the 
 very principles propounded. If we suppose a 
 young animal to have been repeatedly, and at 
 short intervals, exposed to a severe refrigerating 
 influence, the blood is every time determined to 
 the internal organs, and the means which we 
 subsequently employ, to overcome the conse- 
 quences induced, imperfectly restore the func- 
 tions of the body ; and if these means be sus- 
 pended, and cold again be applied while the 
 system has but partially regained its energies, a 
 similar but more serious effect follows, as the 
 heart and the lungs are successively oppressed by 
 new difficulties before they had risen superior to 
 those occasioned in the first place. The repeated 
 application of cold places the constitution of a 
 
AND ANIMAL LIFE. 137 
 
 young animal precisely in the same situation as 
 that of the adult when distressed by the same 
 cause. 
 
 After this explanation, it is scarcely necessary 
 to say, that, if an animal of mature years be sub- 
 jected to the same conditions, it is more than 
 probable that we shall ultimately fail in our en- 
 deavour to restore the action of the vital organs. 
 
 CXLVI. It is remarked by Dr EDWARDS, that, 
 when an individual has been exposed to a degree 
 of cold disagreeable to the animal economy, the 
 faculty of generating heat is diminished for some 
 time, even after the system appears to have re- 
 gained its accustomed temperature. In illus- 
 tration of this opinion, he relates a case in which 
 a young man is stated to have fallen into the 
 Seine in endeavouring to walk upon the ice : 
 from his vigour and agility, he speedily extri- 
 cated himself from his perilous situation, and 
 although his health was not affected, he was an- 
 noyed for three days with a continual sensation 
 of cold. This physiologist gives no rationale of 
 the phenomenon, except, " La faculte de pro- 
 duire la chaleur n'a pas repris toute sa force ; 
 car on ne saurait, quelque temps apres, s'exposer 
 sans inconvenient a un degre de froid qu'on sup- 
 portait auparavant sans malaise." * In this in- 
 stance he states a fact which is evident to every 
 
 * Page 249. 
 
138 THE LAWS OF ORGANIC 
 
 observer, and remarks that the focus of heat lias 
 its faculty lessened, without informing us of the 
 precise nature and conditions of this power, 
 whose office it is to distribute warmth through- 
 out the system. , 
 
 In the case which he brings forward, we have 
 to consider the operation of two causes, the ap- 
 plication of cold, and the impression of fear upon 
 the mind ; the former is an external depressing- 
 power, the latter an internal The tendency of 
 both is to disorder the functions of the heart and 
 lungs, by deranging the equal distribution of the 
 blood submitted to their influence. After the 
 system appears to possess the. usual degree of 
 sensible heat, the ordinary state of the circulation 
 is not julhj developed ; and it is therefore at this 
 time, and from this cause, that the sensation of cold 
 is felt, and that the power of resisting this agent is 
 diminished. 
 
 CXLVII. In corroboration of these principles 
 it is found, if an animal has its temperature re- 
 duced by the application of cold, that the dimi- 
 nution is successive without any additional severity 
 being added to the uniform cause to account for 
 the gradual increase of the effects. 
 
 If we suppose the agency of cold to be esti- 
 mated by 20, and the immediate reduction of 
 the temperature by 30, in considering the in- 
 fluence of the first we shall be enabled to give 
 reasons for the increase of the latter. The im- 
 
AND ANIMAL LIFE. 139 
 
 mediate reduction cannot be denied to originate 
 from the determination of blood to the thoracic 
 and abdominal organs, and as the power which 
 occasioned this alteration is still applied to the 
 surface of the body, its depressing energy is still 
 great, because it has to act on the capillary vessels, 
 already enfeebled by their previous loss, but more 
 enfeebled by the deteriorated action of the heart 
 and lungs, whose office it is to supply them with 
 blood calculated from its properties to stimulate 
 the external circulation, and thereby to render 
 it superior to the influence of the cold ; but this 
 state of the economy being absent, the refrige- 
 rating power continues to operate, and as this 
 proceeds, unless reaction takes place, the effects 
 progressively increase to 40, 50, or 60. 
 
 CXLVIII. The explanation of this and the 
 preceding phenomena does not require the con- 
 sideration of that unknown and much magnified 
 power, the vital principle. The path we have 
 pursued has been simple and straight-forward, 
 and the elucidation of the principles, if allowed 
 to be correct, is immediately brought to bear on 
 the purposes of life, while those views that have 
 been hitherto entertained on this subject have 
 little or no application to recommend them. 
 
 CXLIX. From the preceding observations 
 it is evident, that the plan which Dr EDWARDS 
 has employed to estimate the faculty which an 
 animal possesses, at different ages, of generating 
 
140 THE LAWS OF ORGANIC 
 
 heat, is inaccurate ; and if this fact be considered 
 established, it necessary follows, that the whole 
 of his reasoning, connected with the present 
 subject, is fallacious or imperfect. I hope it has 
 been sufficiently proved, that the temperature of 
 two individuals may be the same in degree, and 
 the source to which this is attributed similar in 
 both, and yet one may be almost frozen to death 
 while the other is comparatively little affected ; 
 and, still further, that two individuals, as in the 
 present instance, will recover, by the application 
 of warmth, with different degrees of facility, 
 without being compelled to suppose, with this 
 physiologist, that the conditions which regulate 
 this phenomenon are derived from the laws of 
 the generation of animal heat. 
 
 CL. If the system of the infant and adult 
 were precisely the same in regard to circulation, 
 sensibility, and the chief of the organic functions, 
 it would be consistent to employ the means 
 which he has employed, and correct to draw the 
 conclusions which he has drawn from them; but 
 it is impossible to allow this mode of proceed- 
 ing, since the systems on which he experiments 
 are as opposite as the results which they give. 
 The number of respirations, and the frequency 
 of pulsations in a given time, the power and 
 character of digestion, and the state of the inter- 
 nal organs, are too important to be overlooked in 
 calculating the influence of an external agent. 
 
AND ANIMAL LIFE. 141 
 
 CLI. In advanced life the constitution is high- 
 ly sensible to cold, but this susceptibility is not 
 referrible to a state of the circulation analogous 
 to that which predominates in the infant, but 
 depends on other principles. At this period the 
 lungs and the heart do not exhibit that energy 
 which characterized their action at the com- 
 mencement of manhood ; the blood is trans- 
 mitted sparingly, and with little force, to the 
 surface of the body ; and from this cause the 
 capillary vessels possess little stimulus to resist 
 the influence of cold, and, therefore, if this be 
 applied, it is quickly accompanied with disagree- 
 able sensations. 
 
 CLII. From the preceding observations we 
 may draw the following conclusions : 
 
 1. That young animals possess an equal, if not superior, 
 
 faculty to adults for the generation of animal heat. 
 
 2. That the facility with which an animal bears exposure 
 
 to cold, is regulated by the distribution of the blood 
 at different periods of life. 
 
 3. That individuals of the same class, and of the same age, 
 
 differ in their power of resisting cold according 
 to the character of the circulation and the force with 
 which the blood is propelled by the heart. 
 
 4. That the ease with which animals are recovered after 
 
 exposure to cold is modified by the previous condi- 
 tion of the circulation, and consequently is not regu- 
 lated by their different powers of generating heat. 
 
 5. That the more sudden diminution of the temperature 
 
 in summer, on the application of cold, is not explain- 
 
THE LAWS OF ORGANIC 
 
 ed on the supposition that less heat is generated at 
 this season than in winter,, but is explained in taking 
 into account the general and more equable distribu- 
 tion of the blood. 
 
 6. That the beneficial or injurious effect of cold will at all 
 
 times be regulated by the principles here stated, 
 
 7. That the power of generating animal heat is in no case 
 
 to be estimated by the application of cold to the body, 
 nor by the consumption of oxygen ; a difference in 
 the constitution, inappreciable to our senses, will ren- 
 der the former mode incorrect, and the magnitude 
 and activity of the lungs are too intimately connect- 
 ed with other functions of the system, or with the 
 variety of states influencing these, to allow the physi- 
 ologist to deduce legitimate conclusions from such 
 premises. The thermometer is the only means we 
 possess to ascertain this point. 
 
AND ANIMAL LIFE. 143 
 
 CHAP. VI. 
 
 The manner in which the System is adapted to the 
 influence of Cold. 
 
 CLIII. THE facility with which we support 
 the varieties of seasons, or the extremes of dif- 
 ferent media, has, from the earliest records of 
 observations, been continually adverted to, and 
 has also been productive of many opinions. To 
 ascertain the laws which regulate the capabilities 
 of the system in withstanding the operation of 
 cold, is even yet a subject of great interest 
 and importance. Although modern science has 
 thrown considerable light on the influence of 
 certain agents, which more or less contribute to 
 explain the difficulties, yet it must be acknow- 
 ledged, that we have not hitherto possessed satis- 
 factory principles which apply to general effects 
 or ascend to general causes. 
 
 CLIV. In treating of the powers of the system 
 in resisting the agency of cold, it is scarcely 
 necessary to state, that the present chapter is a 
 continuation of the principles previously brought 
 forward in the two preceding, viz. " On the dis- 
 tribution of the blood at different ages," and " On 
 the temperature of the body at different ages." 
 Whatever facts may on the present occasion be 
 
144 THE LAWS OF ORGANIC 
 
 adduced, can be considered only as further illus- 
 trations of the correctness of what we have al- 
 ready discussed. 
 
 CLV. The wisdom of Providence is shown in 
 the structure of organic matter, and in the deli- 
 cate adaptations appropriated to its support and 
 development ; but, in forming these, it has had 
 regard to the general changes of the universe, 
 which exhibit, in a striking manner, the wise 
 designs of its pervading spirit. The seasons of 
 the year follow each other in regular succession, 
 for the well-being, not only of the vegetable, but 
 also of the animal creation. If the order were 
 reversed, the animal and vegetable constitution 
 remaining as at present, neither the one nor the 
 other could exist. The gradual steps, by which 
 organized matter accommodates itself to the in- 
 fluence of external causes, would be disturbed, 
 and a repetition of this disordered action would 
 speedily annihilate the functions of organic and 
 animal life. 
 
 CLVI. During the warm months of summer, 
 the circulating fluids of animal and vegetable 
 matter, as previously stated, are more generally 
 distributed throughout its capillary vessels; in 
 the former it has been considered as constituting 
 a state of circulation designated external., in con- 
 tra-distinction to that which is observed in the 
 severity of winter. The powers of life would be 
 as much endangered by a sudden transition from 
 
AND ANIMAL LIFE. 1451 
 
 summer to winter, as from winter to summer, 
 on account of the unprepared state of the circa* 
 lation to adapt itself to such alterations. To ob- 
 viate such evil consequences, spring and autumn 
 are given. The mild and enlivening influence of 
 spring may be said to give motion, and, at the 
 same time, security to the different fluids to dif- 
 fuse themselves, by which means animated Na- 
 ture is almost imperceptibly adapted to bear the 
 more stimulating power of summer ; and when 
 this season has performed its revolution, the ex- 
 ternal capillary circulation is modified by the in- 
 fluence of autumn, and is thus prepared by the 
 most gentle degrees to sustain the keen air of 
 winter. 
 
 CLVII. If proofs were required to strengthen 
 this opinion, it would not be difficult to adduce 
 facts that strongly corroborate its validity. We 
 observe, in a variety of instances, when the tran- 
 sitions of seasons are abrupt, a train of conse- 
 quences that beautifully harmonizes with the 
 principles propounded. It sometimes happens, 
 while the external character of the circulation is 
 maintained by the warm days of autumn, that 
 the cold bleak winds of this season suddenly set 
 in ; and when this occurs the circulation is taken 
 ~by surprise, the blood is quickly determined to 
 the internal organs,/re?7z the enlarged surface which 
 it offers to the influence of cold, giving rise to the 
 various forms of catarrh, inflammation of 
 
 K 
 
146 THE LAWS OF ORGANIC 
 
 bronchia and lungs, and particularly to dysen- 
 teric symptoms. These diseases, at this period 
 of the year, are so prevalent that they are 
 occasionally supposed to be contagious, an 
 idea by no means correct. That many indi- 
 viduals are affected with the same complaints 
 at this period cannot be called in question, but 
 the number is no proof whatever that these are 
 propagated by contagion. The universality of 
 the diseases is against the supposition, and con- 
 tributes much to show their non-contagious 
 nature. The causes which produce these affec- 
 tions are general, and the systems on which they 
 have to act are in similar circumstances. If one 
 individual be subject to dysentery or catarrh, 
 from the condition of the circulation constituting 
 a greater degree of susceptibility, it is reasonable 
 to suppose that a thousand may be similarly si- 
 tuated : they possess the same liability, except in 
 so far as this liability is modified by a difference 
 of dress, mode of living or pursuits, or original 
 constitution. The minute investigation of the sub- 
 ject does not strictly belong to this chapter, and 
 therefore we must be satisfied at present with its 
 general illustration. 
 
 CLVIII. If the unexpected cold of winter 
 produces unfavourable results upon the system, 
 we perceive that the unusually warm days of 
 spring also occasion analogous effects. The sun, 
 that gives premature development to vegeta- 
 
AND ANIMAL LIFE. 147 
 
 tion, tends also to promote an excitation of the 
 animal frame, and both equally suffer from the 
 same cause. The circulation of the sap in plants 
 acquires greater motion, and more invigorating 
 properties from the application of the sun's rays : 
 these conditions form what is called its vitality, 
 the energy of which is displayed in the evolution 
 of the bud, leaf, and flower ; but it is probable 
 that these are put forth at a time when the con- 
 tinuance of the weather is little to be depended 
 upon ; and if to a few warm days succeed nights 
 more severe than is compatible with their pro- 
 gress, we observe that they soon languish and die. 
 
 To say that they suffer from their extreme 
 sensibility, is no explanation of the laws which 
 regulate their economy. The capillary system 
 of plants changes with the seasons, as well as that 
 of animals. The minute vessels of its organiza- 
 tion are charged with a peculiar fluid, and the 
 qualities of this contribute to create others still 
 less cognizable by microscopic means, presenting 
 an enlarged surface of circulation to the influence 
 of cold. The leaves of plants may be considered 
 to compose their surface, and, from the number 
 of these in spring, we may estimate the proba- 
 bilities of danger. 
 
 The dread of the agriculturist is the too early 
 appearance of vegetation. His fears are not ex- 
 cited by the mere symptom of germination, but 
 
148 THE LAWS OF ORGANIC 
 
 by the liberal expansion of leaves ; and how often 
 with anxiety does he look forward to the fall of 
 snow to protect the tender plant. His observa- 
 tions, although unenlightened by a knowledge 
 of those principles on which the effects depend, 
 are valuable, as they are in accordance with views 
 proposed to explain the nature of those principles. 
 
 CLIX. If we take a view of the animal eco- 
 nomy at this period, in which vegetation dis- 
 plays its precocity, we shall observe that its more 
 perfect systems are equally exposed to, and in- 
 jured by the sudden change from heat to cold. 
 The warmth of spring is a stimulus to the sur- 
 face of the body and the functions of the lungs. 
 The blood, that was previously concentrated to 
 the more vigorous capillary vessels, becomes now 
 diffused among the most minute, making the 
 extremities and external parts of the body near- 
 ly as warm as the internal, which is never the 
 case during the severity of winter. 
 
 The distribution of the blood having under- 
 gone this alteration preparatory to the fervid and 
 uniform days of summer, is checked by the cold 
 nights of spring ; from which cause, catarrhs, in- 
 flammations, and fevers are produced as in au- 
 tumn. The only difference between these two 
 seasons is, that autumn acts upon the system by 
 repressing too violently the conditions of the cir- 
 culation derived from summer, while spring, 
 having changed too early thje circulation charac- 
 
AND ANIMAL LIFE. 149 
 
 teristic of winter, disturbs it by re-establishing 
 abruptly its former state. 
 
 In both instances the physical conditions of the 
 system are the same, an enlarged surface of blood 
 zs subjected to the agency of cold, without the capa- 
 bility of the one being proportioned to the circum- 
 stances of the other. 
 
 CLX. The knowledge of the opposite states of 
 the sanguiferous system, at various seasons, ex- 
 plains, in a satisfactory manner, the powers of vi- 
 tality in resisting the effects of cold. We are not 
 necessitated to have recourse to the supposed ex- 
 istence of an ideal principle, and, by endowing this 
 with convenient properties, to give the semblance 
 of an explanation of the phenomena of organic life. 
 Nor are we compelled to grant to Dr EDWARDS 
 that the greater or less consumption of oxygen, 
 at the various seasons, is the cause why the frame 
 conforms to external circumstances. This opi- 
 nion, and many others connected with it, have 
 been shewn to be incorrect in the preceding chap- 
 ter. We perceive the vegetable and animal to pos- 
 sess corresponding general characters of circulation 
 at different seasons of the year ; and we also re- 
 mark, that these characters are influenced by ex- 
 ternal causes in the same way. 
 
 CLXI. As we proceed from south to north, 
 the constitution of man changes with the chang- 
 ing climates ; his susceptibility of cold is 
 
150 THE LAWS OF ORGANIC 
 
 nishedby natural adaptations of the system, such 
 as the more confined distribution of the blood, ma- 
 terially assisted by the manners, dress, and mode 
 of living peculiar to the latitude of the country. 
 
 CLXII. In the most northern climates, the 
 inhabitants do not enjoy the same extensive va- 
 riety of seasons that others in more favourable 
 situations possess. Spring and autumn are not 
 the half of their year, the former, to habituate, 
 by imperceptible degrees and long duration, the 
 constitution to bear the oppressive heat of sum- 
 mer, the latter, by a similar wise design, to 
 temper the approach of winter. The animal and 
 vegetable life of these regions is enlivened but 
 for a short time by the rays of summer, and ex- 
 hibits little of the energies of the same invigora- 
 ted by a genial clime, in the development of 
 muscular power, or in the expansion of the intel- 
 lectual faculties, or in the profusion of flowers 
 and fruits. If it were possible for nature to be 
 partial in her gifts, the miserable inhabitants of 
 these climates might be adduced as an illus- 
 tration ; but if she has deprived them of the ele- 
 vated charms of social life, the pleasures of re- 
 finement, or the luxuries of taste, she has given 
 them fewer necessities, and these of a kind more 
 readily supplied. 
 
 CLXIII. Nature has not only been provident 
 in harmonizing the mind of man to his situation, 
 but has also been careful to provide him with an 
 
AND ANIMAL LIFE. 151 
 
 abundance of whatever is required to protect the 
 body from the inclemency of cold, and to support 
 the vigour of the constitution from its influence. 
 The food of northern inhabitants is substantial 
 and nutritious ; it is generally of an animal na- 
 ture ; the clothes in which they are dressed are 
 the skins of different kinds of animals, or, if the 
 labour of art be employed, they are such as are 
 well adapted to defend the surface of the body. 
 The internal organs being rather invigorated than 
 stimulated by the mode of living, and the surface 
 of the body having a moderate temperature, pre- 
 served by additional or warm clo firing, the vital 
 functions are enabled to continue their operations 
 with slight modifications to the system. 
 
 CLXIV. The winter in Paris is frequently 
 found less easy to bear with comfort than the 
 same in countries farther north, where the ther- 
 mometer indicates a lower degree of temperature. 
 The explanation of this phenomenon depends 
 npon three general causes : 1st, The circulation is 
 more exposed to the agency of cold, in this and in 
 similar regions, from the greater heat of autumn, or 
 its longer continuance : %d, The clothing is light, 
 and furnishes an insufficient protection against the 
 severity of cold ; and, lastly, the Jood which is 
 taken is more stimulating than invigorating: all 
 which circumstances are at variance with those 
 which preserve the constitution in more tempe- 
 
152 THE LAWS OF ORGANIC 
 
 rate climates from the evil consequences and 
 painful sensations of cold. 
 
 CLXV. From the present view, it is not diffi- 
 cult to explain the more frequent occurrence of 
 phthisis in countries that seem calculated to de- 
 stroy the tendency to such an affection ; but the 
 circumstances which seem to give security to the 
 system against such a disease are the very cir- 
 cumstances which promote it. 
 
 CLXVI. Much has been written on the action 
 of cold ; and it has been warmly contested, whe- 
 ther it is to be considered as a stimulant or as a 
 sedative? It is manifest, from the development 
 of the principles concerning the distribution of 
 the blood at different ages and seasons, that cold, 
 though primarily sedative, will produce a seda- 
 tive or stimulant effect according to the charac- 
 ter of this distribution and the energy of the thoracic 
 
 organs. 
 
 CLXVII. The spasm of Dr CULLEN is the key- 
 stone of his doctrine of fevers. It was ably sup- 
 ported by himself, and attained great celebrity, 
 and is even yet brought forward by his enthusi- 
 astic adherents, as possessing the same important 
 rank in febrile diseases as first distinctly stated 
 by him. How " a spasm of the extreme vessels 
 proves an irritation to the heart and arteries," 
 neither he nor his followers have explained in 
 intelligible language. If we were to allow the 
 
ANt) ANIMAL LIFE* 153 
 
 existence of such a state of the vessels, we should 
 be necessitated to grant that vegetables have also 
 their spasms, for I have shown them to exhibit 
 the same general laws of organization, and to be 
 affected by the same general causes as the animal 
 economy. But instead of entertaining for a 
 moment such an idea* let the philosophical mind 
 examine the evident operations of physical agents, 
 and it will find that the assumption of this is 
 equally as gratuitous as the vis medicatrix of the 
 same author. 
 
 CLX VIII. The external application of cold, and 
 certain states of internal disease, determine the 
 blood upon the internal viscera, and thereby deprive 
 the capillary vessels of their usual fulness ; but the 
 constriction which succeeds is not the cause of in- 
 ternal congestion or of fever > but is the simple effect 
 of a depressing power, and in no stage of the 
 disease is it to be regarded in the light of a cause. 
 CLXIX. We have, as yet, considered only 
 the influence of a moderate degree of cold, and 
 the principles by which the system conforms to 
 these changes ; but we must now examine the 
 influence of an extreme degree, and endeavour to 
 explain the concomitant phenomena* When an 
 individual is exposed to intense cold, certain un- 
 pleasant sensations arise, such as pain or coldness 
 of the extremities, and oppression of the chest ; 
 Difficulty of breathing, insensibility of the feet* 
 
154 THE LAWS OF ORGANIC 
 
 and a strong disposition to sleep, are a few of the 
 prominent symptoms which are present. 
 
 CLXX. From the almost universal occur- 
 rence of the propensity to sleep, it has been ima- 
 gined by most physiologists, but with little 
 truth, that the nervous system is individually and 
 directly acted upon by the refrigerating agent. It 
 produces the same effects as a powerful narcotic ; 
 and the following explanation will show why 
 these are not to be attributed to the nervous but 
 sanguiferous system. 
 
 CLXXI. I have already stated, that the ap- 
 plication of cold tends to determine the blood 
 upon the internal organs ; and if this be long 
 continued, or severe, the quantity which is sent 
 from the surface and extremities will be propor- 
 tionate to the causes which operate ; and, in all 
 cases in which sleep is induced, the action of these 
 causes has been incompatible with the proper per- 
 formance of organic functions. The numbness 
 of the extremities, the pale and collapsed state of 
 the body, prove that the internal organs must 
 have received more blood than natural; and, 
 from the principles developed in the first chap- 
 ter, it is obvious that every quantity above what 
 is natural, tends to diminish the stimulating pro- 
 perties of the blood and the force of its circulation. 
 
 CLXXII. The difficulty of breathing, and the 
 pain in the chest, support this opinion. From the 
 first disagreeable operation of cold to the com- 
 
AND ANIMAL LIFE. 155 
 
 mencement of the tendency to sleep, the respira- 
 tory functions have been disturbed. The proper- 
 ties of the blood gradually become deteriorated ; 
 and, as these alterations proceed, the heart in the 
 same ratio has its powers of propulsion diminish- 
 ed. From these conditions it necessarily follows, 
 that the arterial blood which is sent to the brain, 
 and other parts of the body, is deficient in its 
 ordinary stimulating qualities. The action of the 
 heart being enfeebled, it is less capable of trans- 
 mitting the blood to the surface of the body, to 
 counteract the injurious effects of cold. From 
 this view, it is manifest that the lungs are, in 
 the first place, affected by the disorder of the ex- 
 ternal circulation ; and this continues to increase 
 according to the severity or duration of the cold, 
 and is also augmented by the inability of the 
 heart to relieve the congested lungs. The quali- 
 ties of the blood having become less stimulating, 
 they are less calculated to excite the action of 
 the sensorial faculties ; and, indeed, every part 
 of the nervous system has the necessary relations 
 existing between it and the sanguiferous deran- 
 ged, relations which regard the properties of this 
 fluid and its quantity in partial circulation. Dr 
 BEAUPRE, in his Historical and Medical Sketch 
 of the Russian Campaign, gives an interesting 
 description of the symptoms characteristic of the 
 influence of cold. 
 
156 THE LAWS OF ORGANIC 
 
 CLXXIII. Individuals exposed to cold are 
 very frequently induced to take a liberal quan- 
 tity of spirits, to protect them, as they imagine, 
 from the depressing effects of this agent ; but it 
 very frequently occurs, that even a slight excess 
 of these ultimately augments, rather than dimi- 
 nishes, its influence. 
 
 CLXXIV. No satisfactory explanation has 
 yet been given of these phenomena : but the fol- 
 lowing, founded on the principles which have 
 preceded, will probably make an approximation 
 towards a rationale. Spirits, of what kind so- 
 ever, excite the action of the heart, and whenever 
 this takes place, the respirations must become 
 either deeper or more frequent, in order to main- 
 tain the essential relations subsisting between 
 the lungs and this organ. The results of these 
 changes are, an agreeable internal feeling of 
 warmth, and diminished sensibility to cold ; the 
 blood, that had before become rather internal 
 than external in its circulation, is now, from the 
 functions of the thoracic viscera being excited, 
 propelled with energy to the surface of the body, 
 and is more equally diffused throughout the 
 capillary vessels, presenting a distribution simi- 
 lar to that which predominates in the child, and 
 in all animal nature, during the heat of summer. 
 
 CLXXV. In the two preceding chapters it 
 was fully stated, how the system of the child, 
 
AND ANIMAL LIFE. 157 
 
 and that of the adult in summer, are more sus- 
 ceptible to cold ; and as I have now attempted to 
 shew that the circulation induced by spirits is 
 precisely of the same character, if the reasoning and 
 illustrations in the former instance are allowed to 
 be correct, it is impossible to deny that the con- 
 clusions to which we arrive in the present are 
 also sound and legitimately drawn. 
 
 CLXXVI. Although the general phenomena 
 in these instances are of the same kind, yet there 
 are certain differences between the state of the 
 system occasioned by spirits and that peculiar 
 to childhood and summer, too important to be 
 passed over. 
 
 The external circulation in summer, and in 
 early life, arises from a permanent and general 
 cause, or of certain organic conditions of the 
 frame, while that which is produced by stimu- 
 lants is from a partial and evanescent cause. As 
 long as the blood is determined to the surface 
 from the regular and increased action of the 
 heart, the system does not materially suffer ; but 
 as this action, if the effect of spirits, very quickly 
 subsides, the vascularity of the capillary vessels 
 is not maintained by the uniform transmission of 
 blood, and consequently the greater surface of 
 blood exposed to the action of cold is left to 
 contend against its influence, without possessing, 
 as before, increased momentum, and highly stimu^ 
 lating properties. This view, conjointly with 
 
158 THE LAWS OF ORGANIC 
 
 others that have been stated, appears sufficient 
 to account for the diminished capability of the 
 constitution to withstand an exposure to cold. 
 
 CLXXVIL There are certain states of the mind 
 which tend powerfully to counteract the effects 
 of cold. Agreeable sensations, or the strong ex- 
 citing passions of the mind, act exclusively upon 
 the nerves appropriated to respiration ; and, by 
 improving the frequency of this function, or by 
 changing the two actions of which it is compos- 
 ed, the blood is invariably better oxygenated, and 
 distributed throughout the system with greater 
 regularity and force. It therefore follows, that 
 the debilitating effects of cold are counteracted as 
 long as the action of the heart is increased by 
 these means, and as long as it continues to circu- 
 late blood possessing such qualities. 
 
 In a violent paroxysm of insanity, the body is 
 little affected by external agents. In attending 
 the interesting lectures of M. ESQUIROL, at the 
 hospital Saltpetriere, Paris, I had frequent op- 
 portunities of observing the powers which the 
 body seems to acquire, during mental aberration, 
 of resisting those agents which, in the natural 
 state of the mind, never fail to be accompanied 
 by painful feelings or evident effects. There are, 
 indeed, several cases on record, in which indivi- 
 duals are stated to have escaped from confinement 
 when affected with insanity, during the greatest 
 severity of winter, without the protection of even 
 
AND ANIMAL LIFE. 
 
 their ordinary dress, and who were afterwards 
 taken, and found to have been exposed for many 
 hours to the bitter wind of the season, without 
 suffering from the exposure. The explanation 
 of this and similar phenomena will not be diffi- 
 cult, if we consider that, in a violent fit of insa- 
 nity, the disposition of the patient promotes mus- 
 cular exertion of almost every kind. Incessant 
 speaking, constant pacing to and fro, and repeat- 
 ed attempts to break all restraints, are a few of 
 those efficient causes that excite the action of the 
 lungs and heart, and which are every way calcula- 
 ted to sustain the augmented stimulus of the blood 
 and its general distribution. The insensibility of 
 the mind to disagreeable impressions is probably 
 another important cause, tending to protect the 
 system from the effects of cold. Respiration is 
 much disordered by two grand classes of sensa- 
 tions, the exciting and depressing. The influence 
 of the former is illustrated by the paroxysm it- 
 self; but when an individual, whose intellectual 
 faculties are undisturbed, is subjected to a pain- 
 ful degree of cold, the various organic derange- 
 ments awaken certain sensations in the mind of 
 a depressing description, and these react upon the 
 function of respiration, destroying its regularity 
 by sighs and deep inspirations, and induce altera- 
 tions in the properties of the blood and the mode 
 of its circulation. But, in a fit of insanity, im- 
 pressions of this kind are not communicated to 
 
160 THE LAWS OF ORGANIC 
 
 the sensorium, or rendered acutely sensible to the 
 individual. The absence of such a slate of the 
 mind allows the insane person to indulge his out- 
 raged feelings without these being controlled by 
 the susceptibility of the body to the agency of 
 external causes, 
 
AND ANIMAL LIFE. 161 
 
 CHAP. VII. 
 
 On the Torpidity of Hibernating Animals. 
 
 CLXXVIII. THE subject of torpidity has oc- 
 cupied, like that of the preceding chapter, the ta- 
 lents of the physiologist and naturalist, and, like 
 the same, is enveloped in much mystery. The 
 greatness of an effect too often blinds the mind 
 in attempting to ascertain its cause, by mingling 
 in the enquiry a degree of wonder or admiration ; 
 and I am disposed to think that the subject of 
 torpidity has been investigated by some with a 
 feeling of this kind. The regularity with which 
 animals have retired to their convenient resorts, 
 the duration of their repose, and the comparative 
 vigour with which they have returned to active 
 life, are certainly occurrences that cannot be re- 
 garded, by the reflecting mind, without a de- 
 gree of wonder and admiration. 
 
 It is not my intention to give a complete his- 
 tory of the different opinions which have been 
 expressed on this subject, nor to treat it so fully 
 as the reader will find it discussed in Dr FLE- 
 MING'S excellent work on Zoology. * I am anx- 
 ious to examine a few of its most interesting and 
 
 * Vol. ii. page 45. 
 
162 THE LAWS OF ORGANIC 
 
 important phenomena, and for this purpose shall 
 consider the three following subjects : 
 
 1 . The nature and influence of those changes which pre- 
 
 dispose to, or precede torpidity. 
 
 2. The state of the system during the repose. 
 
 3. The nature and influence of those changes which pre- 
 
 dispose to, or precede the return to active life. 
 
 CLXXIX. The period at which hibernating 
 animals undergo this extraordinary change is va- 
 rious in the different species, and even in those 
 of the same species. The greater number exhi- 
 bit a decline of the active powers of life, and re- 
 tire to their winter retreats in September and 
 October. At the latter end of autumn the 
 temperature of the atmosphere is much dimi- 
 nished, and at this season of the year cold and 
 bleak winds frequently occur, which tend still 
 more to affect the animal economy, 
 
 CLXXX. I have endeavoured to shew that the 
 circulation of blood at different ages possesses differ- 
 ent characters, and, still further, that thegeneration 
 of animal heat in man is regulated by its various 
 conditions, and not by any power of the lungs in- 
 dependent of these conditions, or any power of the 
 nervous system, as universally supposed. Since the 
 correctness of this opinion cannot be doubted, we 
 have facts on the one hand, and probability on 
 the other, from analogy, to enforce the belief, 
 
AND ANIMAL LIFE. 163 
 
 that those animals, among the warm-blooded, 
 whose temperature is low, or whose susceptibility 
 to cold is great, from the peculiarity in the dis- 
 tribution of the blood, will have the heat of the 
 system so much reduced, as to enfeeble or almost 
 destroy, for the time, the organic functions. By 
 lessening the temperature of an animal, we im- 
 pair, or stop altogether, the digestive process ; 
 and, by the cessation of this, the numerous recre- 
 mentitious changes are affected to a correspond- 
 ing extent. But life can continue for a long time 
 without the ordinary assistance of these functions. 
 It exists when these are active, because there is an 
 expenditure in the system equivalent to the con- 
 tributions. If these were diminished, the excre- 
 mentitious powers remaining the same, the con- 
 stitution would soon perish. Therefore, life is 
 maintained in a vigorous state by a balance of the 
 corporeal faculties, whose office it is to assimilate 
 what is nutritious to the system, or remove what 
 is no longer required. As cold has the tendency to 
 diminish the generation of animal heat, it circum- 
 scribes immediately the desire of food and the power 
 of digestion, and, independently of the direct influ- 
 ence which the latter exercises on other parts of 
 the body, the capability or disposition to move 
 is diminished in the same ratio by the agency of 
 the same cause. In this view we have lessened 
 the contributions and their expenditure ; but as long 
 as a uniformity of action subsists between them, 
 
164 THE LAWS OF ORGANIC 
 
 we have no reason to suppose that life will be de- 
 stroyed, it will be prolonged according to the di- 
 minution of those powers which produce and 
 support it. 
 
 CLXXXI. Cold having occasioned a certain 
 sluggish state of the system, the animal instinc- 
 tively retires from its severity, and fixes its abode 
 for the winter in barns, caves, or holes in the 
 ground. Before it takes up its retreat, the respi- 
 ration, and the production of animal heat, have ex- 
 perienced great alterations; and these changes in its 
 secluded situation progressively increase with the 
 intensity of the cold, till at last the former becomes 
 almost imperceptible, or is performed at great 
 intervals, and the latter is affected to the same 
 extent. " Mr CORNISH applied a thermometer 
 to a torpid bat, and found that it indicated 36 ;" 
 and SPALLANZANI found the chest of a bat, in 
 similar circumstances, to have a temperature as 
 low as 47. We observe, in these instances, a 
 great diminution of temperature, and this never 
 occurs unless it has been preceded by a corres- 
 ponding derangement of the respiratory function. 
 
 At this period the senses are obliterated, the 
 various instincts no longer exist, nor do the ne- 
 cessities of nature any longer prompt the animal 
 to exertion ; its secretions have ceased, nor is there 
 any function in evident action that can materially 
 tend to waste the strength of the body. We per- 
 ceive the slow and almost imperceptible funo 
 
AND ANIMAL LIFE. 165 
 
 tion of respiration, and the weakened motions of 
 the heart ; but these are amply sufficient to sup- 
 ply the demands of the system. 
 
 CLXXXII. The nature and itifluence of those 
 changes which predispose to, or precede torpidity, 
 are manifestly the depressing effects of cold, di- 
 minished temperature, and almost total extinc- 
 tion of every assimilating faculty. But it is im- 
 possible to give limits to life ; it is not a simple 
 power, but an aggregate of powers, the extent 
 and energy of which may be lessened, in the 
 same manner as we modify chemical attraction, 
 by diluting the active materials that dispose 
 themselves to sudden or violent combination ; 
 but, in this case, the laws which regulate the 
 changes are unaltered, the slowness or extent of 
 the operation in the one does not destroy the cha- 
 racter of attraction, nor does the diminution of or- 
 ganic laws in the animal and vegetable creation 
 render the continuance of life impossible. Animal 
 existence and attraction exhibit every gradation of 
 force, from the zoophyte to man, from the tedious 
 formation of a crystal to instantaneous explosion ; 
 and when cold, by determining the blood upon 
 the internal viscera, lessens the generation of ani- 
 mal heat, in co-operation with its consequences, it 
 enfeebles, to the same extent, the activity of ani- 
 mal and organic life. 
 
 CLXXXIII. No part of Nature subject to the 
 laws of organization is indebted for its existence to 
 
166 THE LAWS OF ORGANIC 
 
 the excited activity of its functions,but to the ob- 
 servance of those intimate relations subsisting be- 
 tween the powers which add and those which sub- 
 tract. Whenever the former predominate over 
 the latter, life then displays its exuberance, the 
 plant throws out its leaves or expands its flowers, 
 and the energy of the animal frame is concen- 
 trated to strengthen old or develope new func- 
 tions, or to excite disease ; and when the latter 
 become superior to the former, the plant droops, 
 and the animal decays. But if these powers are 
 equally diminished, as vegetation is in winter, or 
 as happens to animals in a state of torpidity, it is 
 almost impossible to prescribe boundaries to their 
 duration. 
 
 CLXXXIV. Many theories have been pro- 
 posed to explain the cause of torpidity. MAN- 
 GILI imagined that the veins are larger, in pro_ 
 portion to the arteries, in hybernating than in 
 other animals. " He supposes, in consequence 
 of this arrangement, there is only as much 
 blood transmitted to the brain during sum- 
 mer as is necessary to excite that organ to 
 action. In winter, when the circulation is 
 slow, the small quantity of blood transmitted 
 to the brain is inadequate to produce the ef- 
 fect."* PALLAS observed the thymous gland 
 and two small glandular bodies under the throat 
 
 * The Philosophy of Zoology, by JOHN FLEMING, D. D, 
 Vol. II, p. 61. 
 
AND ANIMAL LIFE. 167 
 
 and upper part of the thorax unusually large, 
 florid, and vascular during torpidity. The opi- 
 nion I have brought forward to account for the 
 occurrence of the phenomenon, viz. that it de- 
 pends on the character of the external circulation, 
 the effects of which modify the production of 
 animal heat, whose influence is felt whether ex- 
 cited or depressed, by every organ of the body, is 
 consistent with a variety of facts and analogies, 
 and in harmony with every appearance which 
 these naturalists have adduced in support of their 
 own view. 
 
 CLXXXV. The enlarged glands, their florid 
 and vascular aspect, the seeming superiority of the 
 veins over the arteries, are the very consequences 
 we should expect from the altered distribution 
 of the blood. If these had not been present, 
 the explanation I have given would have been 
 founded on assumed premises, and unsupported 
 by legitimate deductions. As the severity of 
 the cold increases, the circulation is changed ; its 
 vigour and general diffusion become now feeble 
 and concentrated ; the blood, which previously 
 warmed the whole system, is now bestowed upon 
 the internal organs, debilitating their functions, 
 as is proved by the diminution of temperature, 
 and the weak and slow pulsations of the heart : 
 but the determination is not confined to these 
 vital organs, but spreads itself throughout the 
 internal parts, producing congestion, or, in other 
 
168 THE LAWS OF ORGANIC 
 
 words, enlarged glands, swollen veins, and a florid 
 and vascular appearance of almost every viscus. 
 The veins seem to be proportionally larger than 
 the arteries, because the blood can sojourn in 
 them with greater facility than in the arteries, 
 in which motion is communicated to the blood, 
 by the heart, at all times sufficiently strong to 
 make the accumulation less in the one than the 
 other ; and it was simply from this reason that 
 MANGILI observed the veins larger than the 
 arteries, and, from this and other causes explained, 
 that PALLAS had remarked the glandular bodies 
 of the throat more prominent and vascular than 
 usual. 
 
 CLXXXVI. The state of the system during 
 repose is evidently not mere slumber, as has 
 been supposed, for this does not retard the or- 
 ganic functions, but is an extinction of nine- 
 tenths of those powers that constitute its active 
 life, and the fraction which remains is not occu- 
 pied, as in health, in the assimilation of food, or 
 in attending to the multifarious secretory and 
 absorbent actions, but is sluggishly engaged in 
 the performance of respiration and circulation. 
 The former is employed in oxygenating the blood, 
 and in removing from the body certain excre- 
 mentitious matters, the product of the vital ac- 
 tion still going on ; and the latter is feebly con- 
 tracting in order to propel the slender stream of 
 blood to the various parts of the system. In fine, 
 
AND ANIMAL LIFE. 169 
 
 the office of both is to maintain as exact as possible 
 the balance between the powers which add and 
 those which subtract. From the weak propelling 
 force of the heart, and the agency of the exter- 
 nal cold, the energy of circulation and the quan- 
 tity of blood will necessarily diminish, as we re- 
 cede from the heart to the surface of the body. 
 If the wants of the system were not regulated 
 according to these conditions, the function of 
 respiration and the motion of the heart would be 
 inadequate to preserve in existence the collective 
 instruments of life. By circumscribing the extent 
 of circulation by means of ligatures, as was prov- 
 ed by LEGALLOIS, or by lessening the demands 
 of the constitution, as in torpidity, by the suc- 
 cessive reduction of the energy of circulation, and 
 the quantity of blood from the heart to the sur- 
 face of the body, we enable the heart to contract, 
 and the lungs to improve the qualities of the san- 
 guineous fluid. The experiments of LEGALLOIS 
 demonstrate the correctness of what is advanced. 
 " Si avant de detruire la moelle on fait des liga- 
 tures, soit a Paorte, soit a quelques gros troncs 
 arteriels, les resultats sont diflerens, et la des- 
 truction de la meme portion de moelle, qui, sans 
 ces ligatures, eut arrete subitement la circula- 
 tion, sera insuffisante pour produire cet effet. 
 En general, en resserant par des ligatures Teten- 
 due des parties auxquelles le cceur doit distribuer 
 le sang, on diminue la somme des forces dont cet 
 organe a bcsoin pour remplir sa function, et Ton 
 
170 THE LAWS OF ORGANIC 
 
 racourcit a mesure la longeur de la moelle indis- 
 pensable pour 1'entretien de la circulation."* 
 
 CLXXXVII. During the continuance of the 
 lethargy the animal loses much in weight. The 
 experiments of Dr MONRO on the hedge-hog, of 
 MANGILI on marmots, and those of Mr COR- 
 NISH on bats and dormice, are sufficient to con- 
 firm the truth of the statement. It is scarcely 
 possible to conceive that respiration should act, 
 even feebly, for several months, without affecting 
 the weight of the body to the extent observed. 
 It is remarked by MANGILI, that this circum- 
 stance becomes more obvious if the animal has 
 been roused several times from its torpid state ; 
 and this is what we ought to expect if we con- 
 sider that, every time the animal is revived, the 
 functions of the lungs and heart are quickened, 
 thus diffusing a greater stimulus throughout the sys- 
 tem, improving the action of the absorbents and se- 
 cernents, without any food being taken to supply 
 these additional demands. The animal returns to 
 its lethargic condition ; but it is probable that 
 several days transpire before the necessary or- 
 ganic relations are re-established, and, until this 
 takes place, the powers appropriated to subtract 
 exceed those which add, and thus it is easy to 
 account for the diminished weight from repeated 
 reviviscences. 
 
 * Experiences sur le Principe cle la Vie. Par M. LE- 
 GAL LOIS, M. D. p. 144. 
 
AND ANIMAL LIFE. 171 
 
 CLXXXVIII. As the nature and influence of 
 those changes which predispose to or precede tor- 
 pidity were found to be the application of cold 
 and the diminution of temperature, the nature and 
 influence of those changes which predispose to, or 
 precede the return to active life, will consequently 
 be found to consist in the application of warmth 
 and the increase of temperature. 
 
 CLXXXIX. It is not improbable that the 
 system thus emaciated by the evolution of unes- 
 sential matters from the lungs, may become more 
 susceptible to external agents, or uneasy sensa- 
 tions may be excited, the tendency of which is 
 to accelerate the respiration by the slight de- 
 grees of muscular exercise occasioned. But not 
 wishing to indulge in hypotheses, I shall leave 
 the consideration of this point to others. 
 
 CXC. In the months of March and April, 
 the greater number of hibernating animals revive ; 
 and it is at this season of the year that vegetation 
 shows symptoms of returning vigour, from the mil- 
 der state of the atmosphere and the influence of the 
 solar rays. It is imagined by some, that the barns, 
 caves, and holes in the ground, to which these 
 animals have retired, prevent them from feeling 
 the beneficial agency of spring. Dr FLEMING 
 says, (( It cannot be owing to any considerable 
 change of temperature ; for their situation pre- 
 vents them from experiencing such vicissitudes."* 
 
 * Vol. II. p, 69. 
 
172 THE LAWS OF ORGANIC 
 
 There is no place to which these animals retreat 
 that is exempt from the great vicissitudes of sea- 
 sons. If they burrow in the ground, the seve- 
 rity of the cold is softened by their numbers ; but 
 if the degree of cold becomes less intense by 10 
 or 20, the warm atmosphere which they have 
 created will become warmer by the circulation 
 of more temperate air. 
 
 CXCI. As the medium to which they are sub- 
 jected gradually improves in temperature, the 
 blood that was determined to the internal organs 
 is, by the most imperceptible steps, recalled to 
 the surface. The lungs are then enabled to pro- 
 duce a greater effect upon the diminished quantity 
 of the blood ; and as this is more stimulating to 
 the heart, it is propelled with greater force, and, 
 meeting with less resistance, on account of the 
 additional warmth from without, it is distributed 
 more equally throughout the system. While these 
 minute changes are going on, the generation of 
 animal heat is increased ; so that the situation to 
 which the animal is confined has its temperature 
 augmented. The external heat continues to act 
 upon the surface of the body and on the lungs, 
 respiration becomes more frequent and com^ 
 plete, the blood circulates with greater energy, 
 muscular exertion is excited, and these causes, 
 calculated to promote the same object, are progres- 
 sive in their influence ; and the various powers act 
 
AND ANIMAL LIFE. 173 
 
 and react the same series of changes for an inde- 
 finite period, with greater facility and perfection 
 each time, till at last the animal, stirred from 
 within, and stimulated from without, is awaken- 
 ed to the possession and enjoyment of its animal 
 and organic functions. 
 
174 THE LAWS OF ORGANIC 
 
 CHAP. VIII. 
 
 The means by which the System is enabled to bear 
 a Temperature much superior to that of the 
 Body. 
 
 CXCII. From the preceding chapters the reader 
 has probably anticipated the greater part of the 
 views connected with the elucidation of the pre- 
 sent ; and, from the facility with which many of 
 the principles can be applied, may think it unne- 
 cessary to enlarge further upon them : but, for 
 so doing, I hope the importance of the investiga- 
 tion will be a sufficient apology. Different che- 
 mists and physiologists have entertained diffe- 
 rent opinions regarding the powers of the system 
 in accommodating themselves to a high tempera- 
 ture. It is stated by CRAWFORD, that the blood 
 is less venalized in the capillary vessels when the 
 body is subjected to great heat ; and, therefore, 
 the changes which this undergoes in the lungs 
 are less extensive for want of the combination of 
 the oxygen of the air with the usual quantity of 
 inflammable matter contained in the venous blood. 
 Dr EDWARDS of Paris endeavours to show, that 
 less oxygen is consumed in summer than winter, 
 and that the temperature of the system is, on 
 that account, little higher than at the latter sea- 
 son. I have already shown that his experiments, 
 
AND ANIMAL LIFE. 175 
 
 although correct, do not in the least warrant the 
 conclusions that he has deduced from them, as 
 he has omitted to take into consideration the 
 various conditions of the system at the different 
 seasons and periods of life, which have been shown 
 to modify the results of his experiments. It has 
 been supposed by some, that the evaporation 
 which takes place at high temperatures is the 
 principal reason that the effects of heat are coun- 
 teracted ; by others, that the blood is cooled in 
 its circulation from being distributed to parts 
 possessing different degrees of heat. 
 
 CXCIII. It is impossible to deny the great in- 
 fluence which the two latter causes exert in re- 
 ducing the temperature of the body when sub- 
 jected to a heat a few degrees higher than what 
 is natural ; but I cannot consider them sufficient- 
 ly powerful to account for the possibility of bear- 
 ing the degree of heat to which FORDYCE, DE- 
 LAROCHE, and BERGER have been exposed. Be- 
 lieving these causes to be insufficient, and at the 
 same time being persuaded that the views of 
 CRAWFORD are altogether objectionable, I shall 
 attempt to give other reasons to explain the re- 
 sources of the animal economy. 
 
 CXCIV. When an individual is engaged in 
 violent exercise, the blood becomes more equally 
 distributed throughout the system, and the ten- 
 dency of this change is to relieve the lungs and 
 internal viscera of a quantity of sanguineous 
 
176 THE LAWS OF ORGANIC 
 
 fluid, thereby enabling the inspired air to oxy- 
 genate more completely the diminished propor- 
 tion which remains ; or, if he be exposed to ex- 
 ternal heat, precisely the same consequences fol- 
 low. The surface of the body is stimulated and 
 the blood flows to its minute vessels in greater 
 quantity and velocity than usual ; and in this way 
 the lungs and heart are quickly excited, the re- 
 sult of which is that they co-operate with the ex- 
 ternal heat in maintaining the diffused condition 
 of the circulation, and in promoting the same 
 physical phenomena. 
 
 CXCV. If the external heat be very great, 
 the same effects become more apparent ; because 
 the quantity of blood transmitted through the 
 lungs at any one moment diminishes in the in- 
 creasing ratio of the temperature. In xvm. 
 xix. and xx. I explained why animal heat is not 
 in the direct ratio to the quantity of oxygen inhaled, 
 but in the inverse ratio to the quantity of blood ex- 
 posed to this principle. In extending the same 
 view, we shall understand why the system is ca- 
 pable of resisting a temperature of from 240 to 
 260, which was experienced by BLAGDEN. 
 
 CXCV I. After an ordinary expiration, the 
 quantity of air remaining in the lungs is estimat- 
 ed at 280 or 290 cubic inches; but if the tempera- 
 ture of the body be increased from 5 to 10 more, 
 the air will be much rarefied, and, consequently, 
 the same quantity will not continue to act upon 
 
AND ANIMAL LIFE. 177 
 
 the blood. It will undergo this change before it 
 is inspired, which will lessen the quantity re- 
 ceived, and the internal warmth of the chest will 
 also tend to carry this change still farther. So we 
 observe that two causes are in operation, both of 
 which will diminish the usual proportion of air 
 acting on the blood ; and, moreover, this diminu* 
 tion will be in the direct ratio to the increase of tem- 
 perature, retarding its influence, not by the gener- 
 ation of cold, but by setting limits to the generation 
 of heat, 
 
 CXCVII. CRAWFORD endeavoured to shew, 
 by direct experiment, " that when an animal is 
 placed in a heated medium, the sanguineous 
 fluid during each revolution is less impregnated 
 with the inflammable principle; for the venous 
 blood, in these circumstances, becomes gradually 
 paler in its colour, till at length it acquires nearly 
 the appearance of the arterial? The experi- 
 ments which he instituted, for the purpose of 
 proving this point, are far from being satisfac~ 
 tory. 
 
 An animal was confined in a vessel containing 
 atmospheric air, which was at one time surround- 
 ed by water at 55, for 42 minutes, and at ano- 
 ther by water at 104, for the same period. At 
 the termination of the experiment, the air in the 
 former was found to be only one-fourth as pure 
 
 * CRAWFORD, Experiments and Observations upon Animal 
 Heat, &c, p. 387. 
 
 M 
 
178 THE LAWS OF OBGANIC 
 
 as atmopheric air, while that in the latter was 
 one-half. From these results he concluded, that 
 less oxygen is consumed in a heated state of the 
 system than when the medium is cold. 
 
 It is impossible to estimate the changes or con- 
 ditions of the blood by any degrees of alterations 
 which the inspired air undergoes. At one time, 
 when the blood is determined to the internal 
 viscera, by cold or disease, the proportion in the 
 lungs may be calculated at 30, while the natural 
 quantity may be only 10 ; and if this should 
 occur, the air will be vitiated to a greater extent 
 in the former than in the latter case, without the 
 same quantity of heat being produced. It must 
 be obvious to the reflecting mind, that, if the 
 quantity of blood in the lungs be increased three- 
 fold, without the surface which it offers to the 
 air being enlarged to the same degree, that more 
 oxygen may be consumed without the blood 
 having derived the ordinary advantages from the 
 contact. When the proportion of 10 presents its 
 surface of blood to the action of the air, it is proba- 
 ble that this is almost as extensive as that of 30 ; 
 the same capillary vessels are occupied by both ; 
 and if they become congested by the addition of 
 10 or 20, this very state of the vessels may pre- 
 vent the usual complete changes of the blood. 
 In support of this opinion I may observe, that 
 in every instance in which the quantity of san- 
 guineous fluid in the lungs is greater than what 
 
AND ANIMAL LIFE. 179 
 
 is natural, it is less perfectly arterialized ; and 
 whenever the contrary state is present, its qua- 
 lities are improved. 
 
 CXCVIII. CRAWFORD remarks, that, when an 
 animal has been exposed for some time to a high 
 temperature, the blood in the veins assumes the 
 colour of that which circulates in the arteries. He 
 explains this appearance, by stating, that " the 
 sanguineous fluid is less impregnated with the 
 inflammable principle," or, to employ terms more 
 intelligible to modern readers, that the blood has 
 not undergone its accustomed changes in the ca- 
 pillaries of the body, and therefore is less penalized. 
 When the system is subjected to great heat, less 
 blood at any one moment is transmitted through 
 the lungs, the consequence of which is, that it is 
 more perfectly arterialized, and, from the increas- 
 ed action of the heart, returns to the chest in 
 about one half of the usual time. It is therefore 
 manifest, that the blood is favourably circum^ 
 stanced for the operation of chemical changes ; 
 on the one hand its quantity is diminished, and on 
 the other the repetition of these changes is doub- 
 led. These reasons alone are sufficient to explain 
 the altered colour of the blood. 
 
 CXCIX. As CRAWFORD had found this ap- 
 pearance in every instance in which an animal 
 was submitted to warm air or water, he was de- 
 sirous of trying the effects of cold air or water. 
 For this purpose, a dog was immersed in water 
 M 2 
 
180 THE LAWS OF ORGANIC 
 
 at 45, and in a quarter of an hour blood was 
 drawn from the jugular vein, and was thought 
 " to be the darkest venous blood we had ever 
 seen."* This result was considered to support the 
 explanation, viz. that, when the temperature was 
 high, the changes of the blood in the minute ves- 
 sels were less perfect than usual ; but when the 
 temperature was low, these changes were sup- 
 posed to be more complete, accounting for the 
 very dark condition of the venous blood. The 
 dog immersed in water at 45 must have had its 
 heat materially diminished, although this import- 
 ant point was not alluded to. The blood, from 
 the medium in which the body was placed, would 
 be determined upon the internal organs, which 
 would tend to obstruct its proper oxygenation. It 
 cannot, therefore, be denied, that the difference 
 in colour between the arterial and venous fluid, 
 in every state of the system, is to be attributed to 
 its more or less perfect alterations in the lungs. 
 
 CC. If the dog whose blood was very dark 
 had had its temperature augmented, which it 
 ought to have had according to his doctrine, 
 there would then have been a plausibility in the 
 theory ; but it must have lost several degrees of 
 heat, for the blood, in no condition of the system, 
 assumes this aspect, unless the temperature be 
 diminished, and congestion in some part of the 
 body be present. To ascertain the temperature of 
 
 f CRAWFORD, p. 310, 
 
AND ANIMAL LIFE, 181 
 
 the body when immersed in cold water, the fol- 
 lowing experiments were performed. 
 
 EXPERIMENT I. 
 
 A fine adult rabbit, of the temperature of 104, was im- 
 mersed, with the exception of the head, in water of 50i. 
 In two or three minutes, the animal began to shiver ; in 
 five it was removed ; and its temperature was found to be 
 94. It was directly immersed in warm water of 106 for 
 the same space of time, during which it gained 4 degrees, 
 its temperature being 98. 
 
 EXPERIMENT II. 
 
 An adult rabbit, temperature 106, but not so robust as 
 the preceding, was immersed in water of 50 for five mi- 
 nutes, during which time its temperature was reduced to 
 96i: It was immediately placed in warm water of 110 for 
 the same time, at the end of which its heat had risen to 
 98^. We did not think it necessary to keep the rabbits 
 a longer time in the water. They both seemed much op- 
 pressed : and when we consider that one, in the short space 
 of five minutes, lost 10, and the other about 8, we have 
 changes sufficiently great to account for such symptoms. 
 
 CCI. Without the corroboration of the preceding 
 experiments, the description which CRAWFORD 
 himself gives of the appearance of one animal 
 subjected to a cold medium, and of another to a 
 warm one, is sufficient to prove the consistency 
 of the present opinion. The one exposed to cold 
 
182 THE LAWS OF ORGANIC 
 
 showed symptoms of great uneasiness : " the 
 eye in particular seemed to be much swollen, and 
 became dim and languid? 9 but the eye of the 
 other dog, exposed to warmth, retained its bright- 
 ness to the last.* Whenever the blood is pro- 
 perly, or unusually oxygenated, the expression 
 of the eye is such as he describes ; but when it is 
 deficient in its ordinary qualities, it then becomes 
 swollen, dim, and languid : it is swollen, because 
 its vessels are congested, and dim and languid 
 on account of this condition and the deteriorated 
 properties of the blood. 
 
 In all the rabbits to which I have given opi- 
 um, the eye exhibited the appearances 1 have 
 stated ; and in these the temperature was lessened 
 7 or 8, and the distribution of the blood was 
 shewn to have been unequal by the different ap- 
 pearances observed on dissection. 
 
 CCII. It is remarked by CRAWFORD, that " The 
 cold stage of fevers is preceded by languor, a 
 sense of debility, and a diminution in the action 
 of the heart and arteries. The respiration is 
 small, the pulse is weaker than natural, the 
 quantity of blood which passes through the lungs 
 in a given time is diminished, and hence less 
 phlogiston will be discharged from the Hood, and, 
 consequently, less heat will be separated from the 
 f 
 
 * CRAWFORD, p. 313- t Ibid. p. 394. 
 
AND ANIMAL LIFE. 183 
 
 In the cold stage of fevers the surface of the 
 body is collapsed and pale, and the blood is evi- 
 dently concentrated in the internal organs con- 
 tained in the three great cavities of the body. 
 The difficulty of breathing, and oppression in the 
 chest, shew that the lungs and heart are implica- 
 ted ; the pallid aspect of the face, the dulness of 
 the eye, and the pain of the head, or occasional 
 delirium, prove the brain to be affected, and the 
 enlarged liver and spleen demonstrate a similar 
 condition of the abdominal viscera. Since the 
 lungs have more blood than is natural, it is ma- 
 nifest that his idea of a diminished quantity pass- 
 ing through them has little relation to the quart* 
 tity on which the air has to act ; and as this is 
 augmented, the consequences are in harmony 
 with the principles stated in the first chapter, viz. 
 That animal heat is not in the direct ratio of the 
 quantity of oxygen inhaled, but in the inverse ratio 
 of the quantity of blood exposed to this principle. 
 
 CCIII. It is stated by CRAWFORD, that the ca- 
 pacity of the arterial blood for caloric is greater 
 than that of the venous ; and the opinion beauti- 
 fully illustrates his ideas of animal heat, as he 
 imagined this to be extricated in the minute ca- 
 pillary vessels of the system, and not in the lungs ; 
 and it also removes the difficulties which were 
 opposed to the views of Dr BLACK, which suppos- 
 ed the evolution of this principle to take place in 
 the lungs. This important point has been inves- 
 
184 THE LAWS OF ORGANIC 
 
 tigated by several distinguished physiologists 
 since the time of CRAWFORD, and it seems now to 
 be generally believed, that the arterial has a tem- 
 perature of one or two degrees superior to that of 
 the venous blood. This opinion militates very 
 much against the one brought forward by CRAW- 
 FORD, and may be said to destroy the consistency 
 of his theory. 
 
 CCIV. The body was supposed, by CRAWFORD, 
 to possess a uniformity of temperature at the va- 
 rious seasons of the year, and throughout the 
 whole system. The former condition was re- 
 garded as arising from the less perfect changes of 
 the vital fluid in the capillary vessels, in conse- 
 quence of which the quantity of inflammable 
 matter brought by the veins to the lungs was di- 
 minished ; and as he believed the evolution of 
 animal heat to be proportionate to the chemical 
 changes between the inspired air and this inflam- 
 mable matter, it followed, from his doctrine, that 
 less heat would be generated in summer, when the 
 necessities were less, and more in winter, when 
 they are greater. In cxcvni. and cxcix. I 
 have shewn the fallacy of those premises by which 
 he was led to draw this conclusion. The equality 
 of temperature throughout the system naturally 
 flowed from his principles, which supposed ani- 
 mal heat to be given out by the blood in imbib- 
 ing the phlogistic principle from the capillaries. 
 
AND ANIMAL LIFE. 185 
 
 If a thermometer be applied in winter to dif- 
 ferent parts of the body, it will indicate different 
 degrees of temperature ; and, generally speaking, 
 all much less than that of the internal cavities, as 
 proved by the instrument being placed beneath 
 the tongue. In summer there will be a greater 
 equality, because the sanguineous fluid is warmer 
 by one or two degrees ;* it also circulates with 
 greater velocity, and is more generally diffused ; 
 and, independently of these considerations, the 
 atmosphere is more temperate, tending rather to 
 court than repel its equable distribution. 
 
 CCV. When the body is the warmest, 
 the blood cannot be cooled to any great extent 
 in the course of its circulation \ and, therefore, 
 when the system has a demand for its various 
 resources to overcome the excessive heat to which 
 it is exposed, the distribution of the blood can- 
 not be regarded as a very efficient means, as sup- 
 posed by Dr MONRO, Secundus, of Edinburgh, 
 and Mr BELL of Manchester. 
 
 CCV I. The evaporation from the lungs and 
 surface of the body is the most powerful agent 
 that physiologists have alluded to, in controlling 
 the temperature of the system ; its beneficial 
 effects are experienced in inflammatory fevers, 
 and it is often promoted in diseases, in order to 
 equalize the circulation and reduce the tempera- 
 ture ; but its office is to remove the heat already 
 * Via. EDWARDS, p. 489. 
 
186 THE LAWS OF ORGANIC 
 
 existing, and not to set limits to its production ; it 
 is an effect which tends to preserve the constitution, 
 but is not the cause that regulates the generation 
 of animal heat. 
 
 CCVII. When an individual has been using 
 violent exercise for some time, perspiration flows 
 profusely from the body. Is this to diminish the 
 heat, or to retard its generation ? Or, if we sup- 
 pose the same to be exposed to a medium of 
 100, an evaporation from the surface takes place 
 proportionate to the external temperature; if 
 the medium become 150, evaporation continues 
 to correspond ; if that be raised to 200 or 250*, 
 the body is literally suffused with moisture. 
 Since, in the first instance, perspiration was the 
 consequence of increased heat, without having the 
 least influence on the source which produces it, 
 for it continues to flow as long as the muscular 
 exertion remains, and ceases as soon as this sub- 
 sides, or as soon as the system recovers its regu- 
 lar temperature, it cannot be regarded as a cause 
 that regulates the production of heat.* 
 
 CCVIII. The profuse quantity of perspira- 
 tion does not affect the reasoning, for this is 
 merely in accordance with the excessive heat of 
 the body. If we could, by exercise, produce as 
 great a temperature as is occasioned by the ex- 
 ternal medium, we should observe the same re- 
 sults ; but in this case we could not say that the 
 
 * Dr EDWARDS, pp. 254, 488. 
 
AND ANIMAL LIFE. 187 
 
 perspiration had protected the system from the 
 further production of heat : we might with truth 
 assert, that it had preserved it from its injurious 
 effects. If an individual be confined in a warm 
 moist atmosphere, or in heated water, he is very 
 soon oppressed, because perspiration is retarded 
 in the one case and prevented in the other, and 
 consequently the heat accumulates. 
 
 CCIX. There is a great difference between 
 the powers that relieve the system from the 
 effects of heat and those that circumscribe its 
 evolution. The former are simply the exten- 
 sion of the ordinary and obvious laws of the ani- 
 mal economy ; the latter are the result of a prin- 
 ciple less evident, and exercised only on extra- 
 ordinary occasions. The excessive heat of 240 
 or 260 would destroy the body, if the 260 in- 
 creased the generation of heat in the ratio of its 
 numerical progression ; but every degree, from 
 the temperature of the body to 260, modifies the 
 production of heat by augmenting the rarefaction 
 of the air within the chest, thus successively dimi- 
 nishing the quantity of oxygen submitted to the in- 
 fluence of the blood. 
 
 When an individual has been exposed to great 
 heat for some time, as in an oven for example, we 
 observe, that, on quitting this, his breathing is quick 
 and short, presenting symptoms somewhat simi- 
 lar to those occasioned by running, or excessive 
 exercise. When such arise from the latter causes, 
 
188 THE LAWS OF ORGANIC 
 
 they have been stated in xxi. as originating from 
 the diminished quantity of air within the chest ; 
 and it appears equally consistent to refer those 
 co-existent with great heat to the same physical 
 principle. If, therefore, the air is rarefied before 
 it is inspired, and if its general bulk be subse- 
 quently materially lessened; and if, in conjunction 
 with these two conditions, we consider, that the 
 quantify of air in the lungs indispensable to main- 
 tain the powers of life is very much rarefied by 
 an extensive and constant evolution of caloric, 
 we are enabled to appreciate the boundaries 
 which Nature has set to the generation of animal 
 heat. 
 
AND ANIMAL LIFE. 
 
 CHAP. IX. 
 
 The Influence of Disease on the Production of Heat. 
 
 CCX. To do justice to this subject would 
 require more time than I can at present devote 
 to it, and more correct and multiplied data than 
 the records of medical science furnish. The va- 
 rious states of the pulse, the appearance and quan- 
 tity of the excretions, the expression of the coun- 
 tenance, the colour of the skin, the operation of 
 the mental powers, and many other conditions 
 of the system, have been anxiously inquired 
 after and carefully studied when symptoms of 
 disease were urgent, while the changes in the 
 temperature of the body, or in the distribution 
 of the blood, have never been objects of minute 
 consideration. 
 
 CCXI. We cannot expect to derive much exact 
 knowledge from the ancients ; their ideas con- 
 cerning the source of heat were crude and falla- 
 cious, and their acquaintance with the most im- 
 portant laws of the animal economy, or of the 
 obvious connections of the different organs, or of 
 the degrees of influence which one part of the 
 body exercises over another, was necessarily 
 bounded or empirical. If we turn to the moderns, 
 we have abundance of valuable facts in almost 
 
190 THE LAWS OF ORGANIC 
 
 every department of medical science, except on 
 the subject of animal heat in relation to disease. 
 While chemists have been contending about the 
 quantity of oxygen consumed in a given time, 
 or about the proportions of carbonic acid and 
 vapour formed by the changes in the lungs ; 
 physiologists have been equally busy, but less 
 beneficially occupied, in endeavouring to prove 
 the efficiency of the nervous system in the gene- 
 ration of heat, in attempting to show that galva- 
 nism and the nervous fluid are the same or in 
 labouring to demonstrate that animal heat is 
 nothing but a secretion. If these opinions were 
 to be tested by their contributions to practice, or 
 by the extent of their suggestions to the same, I 
 fear they would be found like many other views, 
 whose only support is the ingenuity of their au- 
 thors. 
 
 CCXII. To these causes we are to attribute the 
 routine practice of the profession -the adherence 
 to what is old, or the avidity for what is new. 
 
 CCXIII. If we take into consideration that 
 the greater number of diseases arise from causes 
 that over-excite the respiratory and sangui- 
 ferous functions, or from causes that diminish 
 their energy, it is certainly important to know 
 in what way these agents influence the sys- 
 tem. In all local and acute inflammations the 
 temperature is augmented, the pulse is more fre- 
 quent, full, or bounding, the sensorial powers are 
 more or less disturbed, and the secretions are also 
 
AND ANIMAL LIFE. 191 
 
 irregular. The degree of temperature is regulat- 
 ed by the situation of the organ affected, or 
 by the disorders which this has communicated 
 to the lungs and heart. If, for example, any of 
 the viscera of the thorax be the seat of inflamma- 
 tion, we have then the flushed or livid counte- 
 nance, according to the stage or severity of the af- 
 fection, the pulse is, for the most part, hard and 
 frequent, and a variety of other symptoms are 
 present equally characteristic of the local disease. 
 The increased frequency of respiration, and the 
 preponderance of its expiratory character, are to 
 be regarded as the principal causes in augment- 
 ing the evolution of heat. Before disorganiza- 
 tions occur, the blood circulates with greater ve- 
 locity through the lungs ; the constant or fre- 
 quent cough prevents or retards its occasional ac- 
 cumulation ; and, from these conditions, the san- 
 guineous fluid is more completely oxygenated, 
 and, having acquired properties more stimulating 
 than usual, it excites palpitation or violent action 
 of the heart. It is at this time that the blood is 
 diffused generally throughout the body. 
 
 The temperature and pulse assume their usual 
 characters as the organs regain their ordinary 
 state; but if, instead of this favourable termination, 
 the disease lose its inflammatory nature,and exhibit 
 asthenic symptoms, we observe the pale and col- 
 lapsed countenance, cold extremities, the surface 
 pallid and shrunk, the patient troubled with 
 
192 THE LAWS OF ORGANIC 
 
 shiverings, the pulse small and frequent, and the 
 generation of animal heat controlled. 
 
 CCXIV. As the efforts of the system were 
 unable to overcome the symptoms by which it 
 was oppressed, the lungs would gradually be- 
 come congested, thereby losing the power of main- 
 taining the ordinary stimulating qualities of the 
 blood ; and as this would be insufficient to excite 
 the usual contractions of the heart, the pulsations 
 would necessarily become feeble, and frequent, 
 because it is compelled to circulate what it receives. 
 The propelling energies being lessened, the vital 
 fluid is not transmitted to the distant parts of 
 the body with its accustomed force, but the veins 
 possess their usual disposition to return their 
 contents ; the consequence of which is, that the 
 viscera of every cavity have their functions dis- 
 ordered by the unusual determination of venous, 
 and the deteriorated properties of the arterial 
 blood. 
 
 CCXV. If we suppose the intestines to be the 
 seat of acute inflammation, the temperature is 
 augmented, because the respiratory functions are 
 again disordered. This effect is not to be refer- 
 red to any nervous connection between the tho- 
 racic and abdominal viscera, but to the changes 
 in the distribution of the blood. We can stimu- 
 late the action of the lungs by warming the in- 
 ferior extremities, or we can oppress it by cool- 
 ing the same ; and, if alterations so far removed 
 
AND ANIMAL LIFE. 193 
 
 from the chest have an almost immediate in- 
 fluence, we can scarcely deny that a similar con- 
 sequence will follow if the abdomen be excited 
 or depressed by disease. Respiration in these 
 cases is generally performed by the thorax, and 
 the patient is extremely careful not to draw deep 
 inspirations in which the abdominal muscles are 
 concerned, from the pain which accompanies the 
 attempt. 
 
 The pulse in this affection is small and fre- 
 quent, sometimes hard ; and these are the condi- 
 tions we should expect from a knowledge of the 
 nature and situation of the disease. The lungs 
 are stimulated to an unusual action, but to a less 
 extent than when their own tissue is exclusively 
 implicated, and therefore the sanguineous fluid 
 is not so well adapted, from its changes, to present 
 the strong and bounding pulse. In accordance 
 with this opinion, it may be observed, that in- 
 flammation of the abdominal viscera seldom or 
 never affords the butfy coat equally well marked 
 with that occurring in the thoracic. 
 
 CCXVI. If the symptoms tend to an unfavour- 
 able termination the temperature is lessened, 
 and we have consequences similar to those men^ 
 tioned in ccxiv. The pulse is at times too fre- 
 quent to count, or too feeble to be felt. If we 
 consider the various important organs belonging to 
 the abdomen, and the nature and activity of their 
 functions, it will at once be apparent, whenever 
 
 N 
 
194 THE LAWS OF ORGANIC 
 
 the blood has the tendency to accumulate here, 
 that an inordinate quantity will very readily be 
 determined to its different viscera ; and it is im- 
 possible for this state to exist without the lungs 
 participating in the congestion : if these are op- 
 pressed, it is not difficult to explain the small, or 
 almost imperceptible pulse, and other concomi- 
 tant phenomena. 
 
 CCXVII. When the system is first affected by 
 local inflammation, the increased temperature is 
 to be attributed to the excited action of the lungs ; 
 a portion of the heat passes off in the form of per- 
 spiration, thus removing the superabundance 
 which is evolved by disease. But if, instead of 
 local and acute inflammation, we have other 
 disordered conditions, giving rise to continued or 
 intermittent fever, the distribution of the blood, 
 and the temperature of the body, are accom- 
 panied by other and more marked changes. 
 
 CCXVIII. In the cold stage of intermittent 
 fever the pulse is remarkably small and fre- 
 quent, and in no other disease have we such an 
 obvious depression of the powers of organic and 
 animal life. Great diminution of temperature, 
 difficulty of breathing, oppression of the chest, 
 violent headache, pain in the course of the spine, 
 and a general feeling of lassitude, are a few of 
 the symptoms which characterize its development. 
 
 Dr CURRIE, in his Medical Reports, allows us 
 to speak with confidence concerning the diminu- 
 
AND ANIMAL LIFE. 195 
 
 tion of temperature in the cold stage of inter- 
 mittent fever. He says, " In the cold stage, 
 the heat is diminished, not on the surface only, 
 as some have imagined, but very probably over 
 the whole system. I have found it under the 
 tongue, and at the axilla, as low as 94, 93, 
 and 921, and on the extremities many degrees 
 lower."* 
 
 CCXIX. No state of the system more satis- 
 factorily shews, that animal heat is not in the 
 direct ratio of the quantity of oxygen inhaled, but 
 in the inverse ratio of the quantity of blood exposed 
 to this principle, than intermittent fever. The san- 
 guineous fluid, from causes unknown to us, leaves 
 the surface and extremities, or rather does not flow 
 to them, and gradually engorges the internal vis- 
 cera; the lungs for some time are less congested 
 than the rest from the character of their office, but 
 they are sufficiently influenced from the first to be 
 incapable of oxygenating the blood as in health; 
 and as their incapability augments with the con- 
 tinuance of the cause, they very soon co-operate 
 with the depressing effects of the disease, to im- 
 pede, if not to destroy, the exercise of their own 
 and every other function of the body. In this way 
 we can account for the small and frequent pulse 
 and all the other symptoms enumerated. The blood 
 is deficient in its usual properties, and there- 
 
 * Medical Reports, p. 153, 
 N 2 
 
196 THE LAWS OF ORGANIC 
 
 fore cannot be expected to excite the contrac- 
 tions of the heart ; and as it is not propelled 
 throughout the arterial system with regularity or 
 force, the remote arteries, from the want of the 
 ordinary vis a tergo, and the accustomed quantity 
 and qualities of the vital fluid, to stimulate these 
 powers, on which their pulsations depend, exhi- 
 bit a feeble or almost imperceptible action. 
 
 CCXX. When these symptoms cannot pro- 
 ceed any farther without endangering life, they 
 are by degrees mitigated by the reaction of the 
 system. It was shown by HUNTER, when an 
 animal is cooled down to a point much lower 
 than what is natural, that the intense cold is 
 counteracted by the evolution of a greater quan- 
 tity of heat ; and it is also stated by Dr ED- 
 WARDS, who has paid considerable attention to 
 this subject, that it arises from the exertions of the 
 animal to escape or remove itself from the de- 
 pressing agent, thereby exciting the respiratory 
 functions to the more perfect oxygenation of the 
 blood ; and it is to a similar cause, conjoined with 
 the means we employ to promote the same result, 
 that we are to attribute the return of the system 
 to its normal state. In support of the general 
 view brought forward, I may allude to the suc- 
 cess of depletion in the cold stage of intermittent, 
 as fully proved by Dr MACKINTOSH of 
 burgh, in a variety of cases. 
 
AND ANIMAL LIFE. 197 
 
 CCXXI. I now proceed to show, that the heat 
 of the body, in different stages of disease, is not a 
 certain indication of the extent to which it is gene- 
 rated. When the system has been violently exer- 
 cised or exposed to great heat, the increased quan- 
 tity of this principle produced is invariably dissipa- 
 ted by cutaneous perspiration and pulmonary eva- 
 poration. The reason of this is evident, the capilla- 
 ries are in a healthy condition ; and, whenever they 
 are excited under these circumstances, they rea- 
 dily discharge the superabundance of caloric, and 
 prevent the system from being oppressed by its 
 accumulation. When the body is suffering from 
 continued fever, the truly inflammatory symp- 
 toms have subsided ; in other words, the excited 
 action of diseased organs no longer stimulates the 
 respiratory functions to increased energy. From 
 the slowness of the respirations, or their incom- 
 pleteness, the inactivity of the patient, the pau- 
 city and derangement of the secretions, the al- 
 most perfect repose of the assimilating functions, 
 the disturbance of the intellectual faculties, and 
 from other co-existing disorders, it is manifest 
 that less heat at this time is generated, and yet 
 the temperature of the body is at times several 
 degrees above its natural standard. 
 
 CCXXII. If we take into consideration that 
 the uniformity of animal temperature is maintain- 
 ed by the balance of two opposite powers, viz. 
 
198 THE LAWS OF ORGANIC 
 
 those that produce, and those those that expend, we 
 shall find an easy solution of the seeming difficulty. 
 
 From the irregular and imperfect manner in 
 which the vital fluid has for some timebeen prepar- 
 ed for the purposes of the system, every function 
 is more or less disordered ; and, among the rest 
 that of the capillaries belonging to the surface of 
 the body. These have not the same capability 
 as formerly of evolving caloric : the consequence 
 is, that even a diminished production of heat ap- 
 pears to present an augmentation, because the 
 powers that expend are greatly inferior to those 
 that produce. The truth of this may be observed 
 in the dry and burning state of the skin. Dr 
 CURRIE, in his Medical Reports, gives several re- 
 markable cases of this condition of the surface, 
 attended by restlessness and great fever, that 
 was almost immediately removed by affusion or 
 sponging of the body, and followed by the re- 
 establishment of health, or the amelioration of the 
 general symptoms. The benefit is not to be re- 
 ferred to the lessened generation of animal heat, 
 but to its lessened accumulation. 
 
 CCXXIII. If we believe that every assimilative 
 process is accompanied by the disengagement of 
 heat, which is certainly a plausible opinion, but 
 of which there is no direct proof, it must be con- 
 sidered extraordinary, unless the above view be 
 received as correct, that the system should, in 
 such a case, possess a temperature much higher 
 
AND ANIMAL LIFE. 199 
 
 than ordinary. We have many symptoms pre- 
 sent which clearly show that the lungs are con- 
 gested, and are otherwise very unfavourably cir- 
 cumstanced for the production of animal heat. 
 
 CCXXIV. The great heat of the surface has 
 induced many practitioners to try depletion at a 
 period of the fever much later than it is generally 
 recommended and found beneficial. When at- 
 tending, as a student, the Dispensary of Dr 
 MACKINTOSH of Edinburgh, I had an opportunity 
 of seeing a great deal of continued fever, and I 
 remember one case which will enable me to illus- 
 trate the present subject. I was called to visit a 
 boy who had been ill for two or three days, and 
 found that he was affected with the fever at that 
 time prevalent in the city. Eight or ten ounces 
 of blood were abstracted ; purgatives, aperients, 
 and blisters were employed till the eleventh or 
 twelfth day, according to the urgency of the 
 symptoms. At this time his respiration be- 
 came so difficult, accompanied with a fixed pain 
 in the chest, and with great dryness and heat of 
 the surface of the body, that I thought it advisa- 
 ble to bleed. Eight ounces of blood were drawn, 
 with slight relief to the breathing ; but the de- 
 pletion was succeeded, in less than a quarter of 
 an hour, by subsultus tendinum. The boy ulti- 
 mately recovered, but the unfavourable symp- 
 toms developed on the second depletion warned 
 me of the danger of bleeding, however the symp- 
 
200 THE LAWS OF ORGANIC 
 
 toms may appear, unless such a measure should 
 be warranted by other signs than simply increas- 
 ed heat of surface. The blood did not exhibit 
 the buffy coat. 
 
 CCXXV. It is often remarked, that fever- 
 patients are occasionally highly susceptible to cold 
 when the temperature of the body is probably 
 104 or 105. Dr CURRIE relates a case where 
 it was 109, and yet the individual complained 
 on the least exposure to cold. Whenever this 
 occurs, we ought to consider the whole or the 
 greater part of this additional heat as the effect 
 of diminished evaporation and not increased gene- 
 ration ; and, if this be allowed, it is easy to ex- 
 plain the great sensibility of the patient. 
 
 The heat of the surface not being derived from 
 the augmented action of the heart and lungs, but 
 depending exclusively on the diseased state of 
 the capillaries of the skin, it is manifest that 
 the external air will speedily lessen the tempera- 
 ture, as it is not supported either by great energy 
 of circulation, or unusually stimulating qualities of 
 the blood. I cannot believe that a person whose 
 temperature is several degrees above the ordinary 
 standard will be particularly liable to feel the 
 immediate influence of cold, if such be the con- 
 sequence of, and maintained by, the vigorous ac- 
 tion of the lungs and heart. The Russian, after 
 having bathed himself for some time in the hot 
 bath, delights to run among the snow, and does 
 
AND ANIMAL LIFE. 201 
 
 not experience any unpleasant sensation ; but his 
 system is not circumstanced as in continued fever. 
 The circulation on the surface of the body is, 
 from the first immersion, excited ; and from the 
 vascularity which succeeds, the lungs, in common 
 with other internal organs, have a smaller quantity 
 of blood to oxygenate, agreeably to the principles 
 laid down in the first chapter ; and, therefore, the 
 blood becomes more stimulating, increasing the 
 action of the heart, and of the whole of the arte- 
 rial system, and consequently protects the surface 
 from the agency of cold. Dr CURRIE observes 
 that, when the system possesses a temperature 
 of 102, 103, 104, or 105 in the hot stage of 
 intermittent fever, " the sensation of heat is 
 now strong and steady, and the accession of 
 external air does not produce a return of chillness 
 as before''* In further corroboration of this opi- 
 nion, we do not find that individuals labouring 
 under thoracic inflammations are as susceptible 
 to this agent as when confined with continued 
 fever. In the former circumstances, the greater 
 part of the heat is attributable to augmented pro- 
 duction, which places the system in a situation 
 somewhat similar to that of the Russian : but, in 
 the latter, the temperature may be said to be 
 truly superficial, as it is not generated by supe- 
 rior powers, nor maintained by the effects which 
 they produce. 
 
 * Medical Reports, p. 155. 
 
THE LAWS OF ORGANIC 
 
 CCXXVI. The views contained in the pre- 
 sent chapter, in regard to practice, are of vital 
 importance. They disclose principles which ex- 
 plain the difference between great heat that is 
 produced by the lungs, and the accumulation of 
 the same arising from diminished evaporation ; 
 and this knowledga at once suggests a mode of 
 treatment different from that pursued in many 
 cases of fever, and which is not derived from em- 
 piricism, but from more extended acquaintance 
 with the laws of the animal economy. The ap- 
 plication of these views to practice will be defer- 
 red till inflammation and fevers be considered in 
 a subsequent treatise. I may, at present, gener- 
 ally allude to a few of the characters which dis- 
 tinguish the production of great heat from its ac- 
 cumulation. 
 
 1. Whenever the pulse is, for the most part, hard, strong, 
 
 and frequent, the respirations more numerous than 
 natural, the heat of the skin greater than usual, and 
 the temperature of the body above the ordinary 
 standard, we may consider the additional heat as the 
 consequence of increased production. 
 
 2. When the above states are modified in degree, accom- 
 
 panied by a burning skin, and great restlessness of 
 mind, the augmentation of temperature is to be re- 
 ferred to increased generation and diminished evapo- 
 ration. 
 
 3. When fever has continued for some time, until the se- 
 
 cretions are evidently much disordered, and the sur- 
 face of the body shews strong marks of asthenic 
 
AND ANIMAL LIFE. 203 
 
 disease, the inordinate temperature sometimes felt in 
 these conditions is to be ascribed solely to diminished 
 evaporation. 
 
 4. Blood drawn during increased production almost always 
 
 exhibits the buffy coat, whereas the same abstracted 
 in purely typhoid affections is seldom or never pre- 
 sent, although the system be apparently oppressed 
 by great heat. It follows also, where the production 
 is slightly greater than natural, that the buffy coat 
 will be proportionate to the influence of this cause. 
 
 5. Whenever the skin is dry and hot, we may consider 
 
 the functions of the capillary vessels to be much de- 
 range4- 
 
 6. When the patient shows acute susceptibility to cold, 
 
 how great soever the temperature may be, we may 
 justly suspect diminished evaporation. 
 
 7. When the temperature is high, and the individual is 
 
 not particularly sensible to cold, we may conclude 
 that the generation of caloric is augmented. 
 
 8. The arteries, in continued fever, in different parts of the 
 
 body, occasionally pulsate much more strongly than 
 natural, even when the truly inflammatory character 
 of the disease is past ; but such a symptom must not 
 lead the practitioner to suppose that this, in con- 
 junction with increased temperature from diminished 
 evaporation, indicates the necessity of depletion. 
 Such a phenomenon frequently occurs in dysentery 
 and other diseases characterised by internal conges- 
 tion. It does not arise from conditions that attend 
 the ordinary excited states of the arteries, viz. the 
 more stimulating properties of the blood and its 
 greater propulsion, but from obstacles to its free cir- 
 culation. 
 
204 THE LAWS OF ORGANIC 
 
 CCXXVII. Many fevers have undoubtedly 
 been cut short by the timely affusion of cold wa- 
 ter, depletion, emetics, or by sudorifics ; and 
 when such instances occur, it is not improbable 
 that the quick pulse, pain of the head, restlessness, 
 great heat of body, and other febrile symptoms, 
 were not occasioned by inflammation or internal 
 congestions, but by a morbid condition of the 
 skin, retarding the ordinary evaporation from the 
 surface. If other causes be assigned for the ori- 
 gin of such fevers, it is difficult to conceive how 
 the employment of such means can act so imme- 
 diately as to remove them. In former times, when 
 the crisis of disease were much attended to, pro- 
 fuse perspiration, or moisture of the skin, was 
 considered to augur a favourable termination of 
 fever. The physician, in regarding this circum- 
 stance as favourable, was correct ; but he was led 
 to his conclusions by experience alone. If we 
 reflect that the high temperature of the body 
 was, throughout the greater part of the disease, 
 the consequence of diminished evaporation, ex- 
 citing and maintaining disorders in every part 
 of the system, it is manifest that the return of 
 the capillaries to their usual function is a symp- 
 tom we cannot too highly estimate. 
 
 CCXXVIII. If the whole of the system can be- 
 come deranged from a general diminution of eva- 
 poration, giving rise to increase of temperature, 
 the same effect may take place in any single part 
 
AND ANIMAL LIFE. 205 
 
 of the body. Phlegmonous inflammations are 
 sometimes accompanied by great heat of their in^ 
 dividual surface. If the temperature should rise 
 above the standard of the system, a point which 
 is yet disputed, I do not see that we are author- 
 ized to suppose that the additional degree is to 
 be attributed to a power of generation belonging 
 to the blood-vessels of the part, but, in a great 
 measure, to diminished evaporation. 
 
 In physics, accelerated motion produces heat ; 
 but there is a great difference between animate 
 and inanimate particles and the laws which re- 
 spectively regulate them. 
 
 We are frequently justified, from obvious re- 
 semblance, in applying the same general reason- 
 ing to both, but we often err in endeavouring to 
 draw analogies where no similarity exists. 
 
 CCXXIX. There is certainly a difference in 
 the results between diminished evaporation afc. 
 fecting the whole surface of the body, and a sin- 
 gle part. In the former instance, the whole cir- 
 culating fluid becomes deranged in its quality 
 and motion ; in the latter, its own vessels, of what 
 kind soever, are, generally speaking, principally 
 if not exclusively disordered. If symptomatic 
 fever occur in these cases, it is as easily explained 
 on the supposition of diminished evaporation as 
 of increased generation of heat. In both cases 
 the temperature of the vital fluid is augmented, 
 and this condition of the blood is communicated 
 
206 THE LAWS OF ORGANIC 
 
 to the heart and lungs, not by means of the 
 nerves, but by the circulating medium. These 
 organs being excited to greater action, produce 
 the same general effects as if they had been pri- 
 marily affected by any other stimulating agent. 
 
 CCXXX. Capillary circulation in the state 
 of health may be considered independent of any 
 power derived from the heart or arterial system, 
 but, in the state of disease, still farther removed 
 in its relations. The deranged action of any 
 portion of its own system destroys the harmoni- 
 ous connection which unites it to the general 
 system ; and, therefore, it is reasonable to ex- 
 pect, if a part of the body be thus circumstanced, 
 that its surface will be incapable of performing 
 the function of evaporation, and, consequently, 
 that heat will be accumulated. Emollient cata- 
 plasms and evaporating lotions are among our 
 most efficient means in cases of phlegmonous in- 
 flammations, where there are great heat and pain ; 
 and it is not improbable that these are in part 
 beneficial, because they reduce the accumulated 
 heat, or promote the proper action of the capil- 
 laries subservient to evaporation. The apparent 
 increase of heat in a local, superficial inflamma- 
 tion, is not attributable to one cause, but to 
 three : 
 
 1st, Diminished evaporation ; %d. Augmented 
 quantity of blood in the part ; and, 3d, The more 
 
AND ANIMAL LIFE. 207 
 
 frequent renewal of this fluid from the excited ac- 
 tion of the capillaries. 
 
 If a given quantity of blood be transmitted to 
 any part of the external surface of the body, the 
 region in which it is distributed will feel warm ; 
 and if this quantity be doubled, without in the 
 least affecting its temperature, the sensation of 
 heat will be proportionally augmented, because 
 a greater number of points, which communicate the 
 sensation, is contained within a given space. If 
 the blood which circulates on the surface of the 
 body be renewed more frequently than natural, 
 the part thus circumstanced will be warmer. The 
 blood on the surface is seldom or never so warm 
 as that which belongs to the cavities ; its tempe- 
 rature is diminished from the influence of an ex- 
 ternal medium, to which the internal circulation 
 is not at all exposed ; but when the vital fluid 
 returns to the surfece in one half of its usual 
 time, the causes which tend to lessen its heat 
 produce less decided effects, from its increased 
 velocity, or diminished sojourn in the capillaries. 
 
208 THE LAWS OF ORGANIC 
 
 CHAP. X. 
 
 The function of the Eighth Pair of Nerves. 
 
 CCXXXI. IT is scarcely necessary to perform 
 new experiments on the present subject to be en- 
 abled to speak with confidence regarding the 
 phenomena connected with the destruction of the 
 eighth pair of nerves. We have a sufficiency of 
 examples illustrating the various changes which 
 occur in the thoracic and abdominal viscera, when 
 this part of the nervous system is injured ; but 
 although the general consequences, with few ex- 
 ceptions, are the same in the different experi- 
 ments brought forward by physiologists, still we 
 observe great discrepancies in the reasoning of 
 those who attempt to explain the precise origin 
 and character of these consequences. 
 
 CCXXXII. Before I adduce any new argu- 
 ments in regard to the eighth pair of nerves, it 
 will be advisable to take a glance at the nervous 
 system in general. This part of the animal eco- 
 nomy has been investigated with more judgment 
 and success within the last few years than any 
 other belonging to the system. Direct experi- 
 ments, multiplied and varied in every possible 
 way, have been appealed to in support of new 
 
AND ANIMAL LIFE. 209 
 
 discoveries, or in refutation of old opinions : thus 
 on the one hand presenting knowledge as an im- 
 moveable point for future advancement, and, on 
 the other, correcting the fallacies of ignorance. But 
 while the present age has been enriched with con- 
 tributions of this kindbyBiCHAT,GALL,MAGEN- 
 DIE, LEGALLOIS, and BELL, it is also distinguish- 
 ed by theories and hypotheses, which are proba- 
 bly almost inseparable from the preceding. The 
 development of one fact in physiology, too ge- 
 nerally gives rise to a multitude of ingenious 
 ideas, which seem to be required to complete the 
 imperfect view which it unfolds ; and it is from 
 this cause that every century is necessitated to 
 retrace its steps to some established truth that has 
 been lost in the refinements or visions of its ad- 
 mirers. " Eh bien ! la physiologic a encore un 
 pied dans la premiere epoque, tandisque deja elle 
 en a place un dans la seconde. C'est aux physio- 
 logistes act u els a lui faire le pas tout en tier." 
 
 CCXXXIII. So natural is it in man to embel- 
 lish what he cultivates, or to colour with his pur- 
 suits every object which he studies, that we have 
 now cerebral phenomena explained on the sup- 
 posed oscillations of the nervous fluid ; the in- 
 flammatory condition of the blood, from the in- 
 terposition of this same agent between its glo- 
 bules;* hypochondriacal and melancholic de- 
 
 * Nequaquam, sed sanguis, cui nullum additamentum ac- 
 cessit, supplementum nullum a nutritionis foco proficiscens, 
 dilatatior, expanditur majorem acquirit capacitatem pro prin- 
 cipio nervoso ipsius gkbulis interposito. LOBSTEIN, p. 119. 
 
210 THE LAWS OF ORGANIC 
 
 rangements, nausea, want of appetite and pal- 
 pitation of the heart, from the diseased state of 
 the nerves ; and, lastly, the generation of animal 
 heat is attributed to secretion, and all secretions 
 are referred to the influence of the nerves. 
 
 CCXXXIV. Some of these opinions have 
 been transmitted, with the diseases they are ima- 
 gined to explain, from a remote period ; and they 
 might have continued for as long a time to per- 
 plex the scientific physician, if important disco- 
 veries had not allowed us to examine them with 
 greater philosophical acuteness. If our know- 
 ledge had been confined to the nerves appropri- 
 ated to the senses or to motion, it would have been 
 impossible to deny, that, as certain parts of the 
 nervous system have obvious functions to per- 
 form, it is not improbable that others, still un- 
 known, may possess the faculty of secreting the 
 various fluids of the body, but the discovery of 
 Mr CHARLES BELL has thrown considerable light 
 on this subject. He proves that " the anterior 
 column of each lateral division of the spinal 
 marrow is for motion, the posterior column is 
 for sensation, and the middle one is for re- 
 spiration ;"* and, still further, " that there is an 
 obvious division of the medulla spinalis, corre- 
 sponding to the cerebrum and cerebellum ; every 
 regular nerve has two roots, one from the ante- 
 rior of these columns, the other from the poste 
 rior : such are the fifth pair, the sub-occipital, the 
 * BELL on the Nerves, p. 22. 
 
AND ANIMAL LIFE. 211 
 
 seven cervical, the twelve dorsal, the five lumbar, 
 and the six sacral. They are common to all ani- 
 mals, from the worm up to man, and are for the 
 purposes of common sensation and motion, or acts 
 of volition."* This discovery enables us to cul- 
 tivate an intimate acquaintance with the consti- 
 tution of the nerves belonging to the thoracic 
 and abdominal cavities, to note with precision 
 their origin, their compound nature, and to un- 
 derstand the character of those endowments 
 which they bestow on the different viscera on 
 which they are distributed. 
 
 CCXXXV. If we believe, with some anato- 
 mists, that the sympathetic nerve is derived from 
 the fifth and sixth, we shall be enabled to speak 
 with confidence of its properties ; or if we grant 
 that it is merely connected with these nerves, we 
 are still able to discriminate its functions, by ob- 
 serving the office of those organs and muscles 
 to which it is distributed, and by noting the con- 
 sequences which follow its partial destruction, or 
 the phenomena which it exhibits on the applica- 
 tion of galvanism. 
 
 The par vagum is evidently a nerve of respira- 
 tory motion; the branch of the fifth and that of the 
 sixth, which form the whole, or constitute a part of 
 the sympathetic, transmit motion or sensibility ; 
 and the whole of the spinal nerves are proved to 
 
 * Ibid. p. 44. 
 
 o 2 
 
TtiE LAWS OF ORGANIC 
 
 possess the same powers ; and as these are com- 
 bined in every thoracic or abdominal plexus or 
 ganglion, it is reasonable to suppose, that the 
 connexion of the various fibres cannot in the 
 least change their individual properties : before 
 they contribute these properties, they exhibit 
 sensibility and motion ; and if they are conjoin- 
 ed, the centres which they form will be sources 
 of sensibility and motion. 
 
 CCXXXVI. If then the whole of the ganglions 
 and plexuses be centres or combinations, partici- 
 pating in the endowments of nerves whose func- 
 tions have been ascertained, it follows that the 
 viscera of the thorax and abdomen, the extremi- 
 ties and surface of the body, are supplied with 
 nervous energy composed of one or both of these 
 qualities. If this view be taken, we leave no 
 nerves to perform secretion or excretion, except 
 it be allowed to the physiologist that the nerve 
 which performs motion in one part of the body 
 is a nerve indispensable for secretion in another. 
 This idea has been embraced by WILSON PHILIP 
 and others, who believe that the formation of 
 the gastric juice depends on the eighth pair of 
 nerves. 
 
 CCXXXVII. When I speak of sensibility 
 and motion, I do not, by any means, confine 
 those terms to the limits of their ordinary accep- 
 tation. I look upon every organ as possessing 
 sensibility and motion corresponding to its office. 
 The contraction of the heart, iris, or sphincter 
 
AND ANIMAL LIFE. 213 
 
 ani, the peristaltic action of the intestines and 
 stomach, the elevation of the ribs, or the inor- 
 dinate action of any of the muscles belonging to 
 respiration, in fine, every motion or contraction 
 of muscular fibre, I regard as depending on ner- 
 vous fibrillce originating from the nerves of motion, 
 modified by the organization of the part or organ. 
 
 CCXXXVIII. Every organ of the system has 
 its proper stimulus : the eye has light, the heart 
 blood, the stomach has food and its peculiar 
 secretion, and the whole of the abdominal vis- 
 cera their various agents ; but the susceptibility 
 of an organ to its stimulus will be proportionate 
 to the fasciculi derived from the nerves of sensa- 
 tion, and the energy with which it acts will be 
 according toth e number or size of fasciculi be- 
 longing to the nerves of motion, and the adapta- 
 tion of the part to promote the intended effect. 
 If we examine the structure of the iris, we shall 
 observe its radiated and circular fibres, which are, 
 by the best authorities, considered muscular ; if 
 then light be transmitted to the retina, the iris 
 contracts in virtue of its sensibility to impres- 
 sions, and the power of motion communicated 
 to its radiated and circular fibres by its nerves 
 of motion. If we examine the disposition of 
 the muscular fibres of the sphincter ani, we 
 observe that these are calculated to produce 
 the necessary effect ; or if we look to the 
 stomach and intestines, we have circular fibres 
 
THE LAWS OF ORGANIC 
 
 which are continually in action for the purpose 
 of propelling or otherwise acting on the con- 
 tents ; in the intercostal muscles, and others ap- 
 propriated to respiration, we have longitudinal 
 fibres, and it is by structural modifications of 
 this description that the various kinds of contrac- 
 tion are produced. Sensibility and motion may be 
 considered as fundamental properties bestowed 
 on all organs, differing only in extent, while the 
 character of the contraction is regulated by its 
 muscular conformation and the nature of its sti- 
 mulus. These properties in the state of health 
 are uniform in their influence, but in disease they 
 are much disordered. In Enteritis the natural 
 sensibility of the bowels is heightened, and trans- 
 mits to the sensorium painful impressions, and, 
 at the same time, the anti-peristaltic action occa- 
 sionally occurs, showing that the nerves of mo- 
 tion are equally deranged. These or similar ob- 
 servations may be applied to every part of the 
 body. 
 
 CCXXXIX. I have alluded to the stimuli 
 of several organs : it is also necessary to remark 
 that these generally place the function beyond 
 our control. The contractions of the heart, the 
 assimilation of food, and the different secretions, 
 are illustrations ; and yet we observe that the will 
 can influence certain functions which are partly 
 voluntary and partly involuntary. In what way 
 the will operates is unknown to us, nor does the 
 
AND ANIMAL LIFE. 215 
 
 investigation particularly concern the physiolo- 
 gist it is sufficient for him to observe that dif- 
 ferent acts of the system are accomplished by the 
 simple volition of the mind. 
 
 CCXL. Whether the sympathetic nerve arise 
 from the brain, or only be connected with it, 
 or whether the system which it forms is to be 
 regarded as independent of the cerebrum and 
 spinal cord, or as constituted to combine and 
 communicate the same influence in the more per- 
 fect animals, are subjects which will continue to 
 perplex as long as anatomy be appealed to as the 
 only guide. 
 
 If the ganglionic system in the lowest orders 
 of animated nature be supposed to preside over 
 the functions of secretion, absorption, and nu- 
 trition, as there is no other system of nerves 
 present, it may be justly asked whence those 
 powers are derived which bestow sensibility and 
 motion ? MECKEL and WEBER remark, that the 
 sympathetic nerve and par vagum are developed 
 in the inverse ratio of each other. In the lower 
 gradations of animal life, the sympathetic nerve, 
 or ganglionic system, is the only nervous struc- 
 ture which is present for sensation and motion ; 
 and, as we ascend in the scale of being, we per- 
 ceive the additional contribution of the par va- 
 gum to supply the multiplied wants of the ani- 
 mal. It is, therefore, probable that these two 
 nerves possess endowments precisely of the same 
 
THE LAWS OF ORGANIC 
 
 kind so far as regards motion, but that the sym- 
 pathetic, besides this common property, has the 
 power of conferring sensibility also. 
 
 It has been proved, that the sympathetic 
 nerve is capable of being excited by galvanism. 
 SCHMUCK, FOWLER, PFAFF, LUDWIG, CREVE, 
 and WEBSTER, have excited the action of the 
 heart, both in warm and cold blooded animals. 
 HUMBOLDT has also produced contractions in 
 some of the inferior orders of animals, as the Umax 
 ater, ostrea edulis, helix pomatia, helix nemoralis, 
 sepia qfficinaliSy by the application of galvanism. 
 It has also been shown, that the diaphragm can 
 be sensibly excited by the same means.* 
 
 CCXLI. All these arguments and direct ex- 
 periments tend to persuade or demonstrate, that 
 the function of the sympathetic nerve is the same 
 as that which belongs to the cerebral and spinal 
 nerves, viz. to distribute sensibility and motion 
 to almost every part of the thorax and abdomen 
 in the class mammalia, and in the inferior orders 
 to diffuse these properties throughout the whole 
 system. 
 
 CCXLII. It was imagined by SGEMMERING 
 and BEHRENDS, that the numerous nervous 
 fibrillae sent by the sympathetic nerve to the 
 heart are not blended with the muscular fibres, 
 but simply accompanied the vessels of circulation. 
 It has since been shown, that these are as inti- 
 mately connected with them as the voluntary 
 
 * LoBSTEIN, p. 174. 
 
AND ANIMAL LIFE. 217 
 
 nerves are with any of the muscles of the body. 
 When galvanism is applied to the sympathetic 
 nerve, which principally supplies this organ, the 
 contractions are increased, because it stimulates 
 the various nervous ramifications in the same 
 manner as the vital fluid ; and from what I have 
 previously stated, it is obvious that the contrac- 
 tions of the heart are modified, in almost every 
 possible way, by the qualities of the blood. 
 
 CCXLIIL Many experiments have been per- 
 formed for the purpose of ascertaining how far 
 the capillary circulation is influenced by the de- 
 struction of the brain or spinal cord, as if it were 
 possible by such means to know the precise rela- 
 tions existing between the capillary circulation 
 and the nervous mass. If we consider that the 
 removal of the cerebrum must derange the ge- 
 neral circulation according to the quantity of 
 blood which such an operation takes from the 
 system, not simply from the blood which is lost 
 in the excision of the vessels, but from what is 
 proper to the organ, or, if we reflect that great 
 disorders in the sanguiferous system will other- 
 wise be induced, how is it possible to draw any 
 positive conclusions from such effects and causes, 
 when a variety of others intervene of which no 
 estimate or conception is formed ? Though we 
 allow that the capillary circulation is indepen- 
 dent of the brain and spinal cord, and this opinion 
 can scarcely be disputed, yet we cannot for 3 
 
218 THE LAWS OF ORGANIC 
 
 moment suppose that it is equally independent 
 of the general circulation. It will be subject to 
 two great modifications : The quantify, and condi- 
 tion of the vital fluid transmitted to its vessels. If 
 the properties of the blood be highly stimulating, 
 the same will immediately influence the circu- 
 lating powers of the capillaries ; if the quantity 
 which is sent is either greater or less than usual, 
 these w ill be sensibly affected ; and if we employ 
 chemical or mechanical means which produce 
 one or both of these circumstances, the results 
 cannot be regarded as affording any indications 
 of nervous influence. 
 
 CCXLIV. The sympathetic nerve is almost 
 universally supposed by anatomists and physio- 
 logists to be indispensable to the offices of secre- 
 tion, nutrition, and circulation, and is also ima- 
 gined to be the source of a multitude of diseases. 
 LOBSTEIN, in enumerating the Pathemata istius 
 nervi essentialia, includes in the list Hypochon- 
 driasis, Morbus Hystericus, Melancholia, Mania, 
 et Febris Intermittens. I shall not, at the pre- 
 sent, attempt to show the fallacy of such opinions : 
 the refutation of the greater number will be 
 found in the different views developed in this 
 work ; and the more minute investigation of the 
 subject will be deferred until we treat fully of the 
 class of nervous diseases. 
 
 CCXLV. The principal arguments hitherto 
 advanced to prove that organic functions are per- 
 formed by means of the sympathetic nerve and 
 
AND ANIMAL LIFE. 219 
 
 par vagum, may be reduced to the following pro- 
 positions : 
 
 1. If the par vagum be cut, the secretion of gastric juice 
 
 is arrested. 
 
 2. Galvanism has been shown to supply the want of nerv- 
 
 ous energy, by accelerating digestion, after the de- 
 struction of the eighth pair of nerves. 
 
 3. The nerves accompany the arteries and muscular fibres 
 
 in their most minute ramifications. 
 
 4. Many nervous fibrillae are distributed on those organs, 
 
 which are destined either for the circulation of blood 
 or the assimilation of food. 
 
 5. The development of the nervous system increases with 
 
 the augmentation of additional organs or their more 
 complete organization. 
 
 6. The secretion of gastric juice is materially retarded by 
 
 the exhibition of narcotics, which are supposed to act 
 on the nerves. 
 
 7. Mental influence occasionally disorders the thorax and 
 
 abdominal functions. 
 
 In Chapter III. I examined the opinions of 
 WILSON PHILIP in regard to the effects aris- 
 ing from the destruction of the par vagum ; and 
 therefore it is not necessary to repeat the same 
 observations to show that the first proposition is 
 incorrect. The experiments at the end of this 
 chapter will satisfactorily prove that the secre- 
 tion of gastric juice is stopped, not on account of 
 nervous energy being diverted from its course to 
 the stomach, but on account of the great disturb- 
 
220 THE LAWS OF ORGANIC 
 
 ance which such an operation occasions in the 
 qualities and distribution of the blood. It has 
 also been shewn in what manner galvanism 
 maintains the function of digestion. It operates 
 as a stimulus, and tends to remove congestion, 
 whether in the lungs or stomach, and thereby 
 allows the former to oxygenate properly the fluid 
 which it receives ; and this, possessing its usual 
 properties, is transmitted to the viscera of the ab- 
 domen ; the consequence of which is, that the or- 
 ganic functions are supplied with blood calculated 
 to support their action. The truth of this view is 
 found in perusing the cases which WILSON 
 PHILIP himself relates. The immediate effect 
 of galvanism was to relieve the oppressive breath- 
 ing ; and, in those instances in which this was 
 employed, the lungs were comparatively healthy, 
 whereas, in those in which it had not been used, 
 the lungs presented " dark red patches," like the 
 lungs of an animal that had " lain dead' 9 for 
 many hours. 
 
 CCXLVI. In proposition 3d, we may observe, 
 that sensation and motion, variously modified, 
 belong to every part of the system. The univer- 
 sal dissemination of these qualities of matter 
 makes an individual sensible to external agents, 
 and gives him the faculty of removing from, or 
 approaching to such, according as these are pain- 
 ful or agreeable ; and it also binds in harmony 
 the different organs of the body, facilitating mo- 
 
AND ANIMAL LIFE. 
 
 lion where it is required, and transmiting sensa- 
 tion when it is necessary. 
 
 CCXL VII. The accurate plates of SCARPA point 
 out the great number of nerves which the heart 
 receives from the sympathetic and par vagum ; 
 and if the distribution of these to an organ is a 
 powerful argument in support of their influence 
 in secretion, it may be asked, what does the heart 
 secrete ? But if they be allowed to give motion 
 and sensibility, it is evident that the function of 
 the organ satisfactorily accounts for the multi- 
 tude of nervous fibrillae. Its constant con- 
 tractions are effected by its nerves of motion, 
 which endow its muscular fibres with a property 
 called irritability, and, unless it possessed this ex- 
 tent of nervous energy, the blood would not be 
 able to maintain its regular action. Secretion 
 and nutrition are accomplished in the vegetable 
 without the assistance of nerves ; and this fact, 
 from the similarity of the functions in both in- 
 stances, naturally leads the mind to conclude 
 that these are the result of laws not directly de- 
 pending on the nervous system. 
 
 CCXLVIII. As we rise in the scale of being, 
 additional and more perfect organs are developed, 
 and the nervous system is also proportionately 
 augmented to meet the demands of these super- 
 added powers. 
 
 CCXLIX. The manner in which narcotics 
 influence the generation of heat, and the secre- 
 
222 THE LAWS OF ORGANIC 
 
 tion of gastric juice, will be considered in the 
 next chapter. 
 
 CCL. The different conditions of the mind 
 have been known, from the earliest observa- 
 tions, to excite or depress the digestive and 
 assimilating organs ; but as this subject is fully 
 treated of in a subsequent chapter, it is unneces- 
 sary, at present, to make any remarks upon it. 
 
 CCLI. It has been observed by every one who 
 has paid particular attention to the division of the 
 par vagum, that great difficulty of breathing im- 
 mediately follows this operation, if performed on 
 both sides, or if the nerves be tied; and although 
 this effect was so obvious, the cause was not accu- 
 rately ascertained till LEGALLOIS proved it by di- 
 rect experiment. It was demonstrated that, when 
 the par vagum was divided, the superior and in- 
 ferior laryngeal branches, distributed to the muscles 
 of the larynx, no longer enabled them, as in 
 health, to open and close the glottis, the conse- 
 quence of which is, that atmospheric air can- 
 not pass in its usual quantity into the chest to 
 produce the ordinary changes of the blood. Al- 
 though the correctness of this explanation has 
 never been questioned, yet a variety of opinions 
 have been entertained in regard to the cause of 
 death.* DUPUYTREN supposed that the air 
 entered the lungs, but did not properly oxygen- 
 
 t 
 * Vide pages 180-1, 200, 2C2, 224, 235, LEGALLOIS. 
 
AND ANIMAL LIFE. 
 
 ate the blood : this was remarked to be of a dark 
 colour, and the temperature of the body was also 
 found diminished. " II pensa done, 1, que tous 
 les animaux auxquels on a coupe les deux nerfs 
 pneumo-gastriques meurent d'asphyxie ; 2, qu'ils 
 en meurent, parceque 1'air atmospherique, quoi- 
 que continuant de penetrer librement dans les 
 poumons et d'y arriver en contact avec le sang, 
 ne peut plus se combiner avec ce fluide, cette 
 combinaison ne pouvant se faire que sous rinflu- 
 ence du principe vital et par 1'intermediaire des 
 nerfs."* 
 
 BLAINVILLE imagined, with HALLER and 
 many other physiologists, that the death of the 
 animal was to be referred to disorder of the di- 
 gestive powers, and various changes of the con- 
 tents of the stomach ; others believed that some 
 great alteration was communicated to the heart, 
 by which means the circulatory system was de- 
 stroyed or disturbed. LEGALLOIS himself con- 
 ceived the death of the animal to be occasioned 
 by the three following causes : " 1> Par la diminu- 
 tion de Vouverture de la glotte ; 2> Par I' engorge- 
 ment sanguin des poumons ; 3> Par I'epanchement 
 d'unfluide sereux dans les branches" t LEGAL- 
 LOIS, in speaking of the effects arising from the 
 division of the eighth pair, says, " la section des 
 deux nerfs affecte a la fois le larynx, le coeur, le 
 
 * LEGALLOIS, p, 178. 
 t Ibid. p. 235. 
 
THE LAWS OF ORGANIC 
 
 canal alimentaire et les poumons."* He ex- 
 plains the affection of the larynx, but the other 
 consequences are difficulties which he does not 
 solve. 
 
 CCLIL From the great and general disor- 
 ders of the viscera, of the thorax and abdomen, 
 it is not easy, unless we seize the first and prin- 
 cipal agent in the chain of causes, to account for 
 the extraordinary effects produced. Impeded 
 digestion, congested lungs, and a vascular state 
 of the heart, have been described by the greater 
 number of those who have prosecuted the pre- 
 sent subject ; and the following experiments, 
 from their conclusive character, will show why 
 such simultaneous results occur, and what is the 
 nature of the relations existing between the dif- 
 ferent organs. 
 
 The following experiments are to prove these 
 propositions : 
 
 1. That the function of the par vagum, and its various 
 
 branches, is to regulate the ingress and egress of at- 
 mospheric air in the act of respiration. 
 
 2. That nervous influence is not necessary for the secre- 
 
 tion of gastric juice. 
 
 3. That the first cause in the disturbance of the organic 
 
 functions is to be referred exclusively to the injury 
 done to the laryngeal nerves, by which means the 
 usual quantity of air does not enter the lungs. 
 
 4. That the death of the animal arises from the three 
 
 causes stated by LEGALLOIS. 
 
 * LEGALLOIS, p. 231. 
 
AND ANIMAL LIFE. 225 
 
 EXPERIMENT I. 
 
 The influence of the par vagum on the Junction of 
 digestion. The three rabbits in this experiment were 
 adults, and about the same size. They were fed at half 
 past six o'clock, A. M. with cabbage leaves ; they had 
 previously fasted sixteen hours. This rabbit had the par 
 vagum divided on one side only, at eight o'clock. Tem- 
 perature before experiment 
 
 Time. Temperature. Observations. 
 
 10 o'clock A. M. 100 Apparently cheerful. 
 12, noon, 10l ditto. 
 
 2, P. M. 102 ditto. 
 
 6, P. M. 103 ditto. 
 
 At six o'clock, p. M. this rabbit was killed. 
 
 Dissection. On opening the chest the lungs collapsed, 
 but were slightly infiltrated ; the heart appeared in the 
 natural state ; nothing worthy of particular remark in the 
 thorax. The stomach, of a smaller size than in the two 
 others, was filled with a homogeneous mass, in which the 
 well-marked characters of vegetable food were absent. 
 The contents of the large intestines were well concocted. 
 The weight of the lungs and heart of this rabbit was three 
 drachms and a half. 
 
 In the following, the par vagum was divided on both 
 sides. Temperature of the rabbit, before experiment, 105. 
 The operation was performed a few minutes after the pre- 
 ceding. 
 
 Time. Temperature. Observations. 
 
 10 o'clock A. M. 98 Respiration very laborious. 
 
 12, noon, 97 ditto. 
 
 2, P. M. 96 ditto. 
 
 6, P. M. 93 ditto. 
 
 At six o'clock, P. M. it was killed. 
 P 
 
226 THE LAWS OF ORGANIC 
 
 Dissection. The heart and lungs of this rabbit were 
 much larger than usual. The lungs were very much en- 
 gorged, presenting several large patches of a dark hepatic 
 colour. The heart was very turgid, and the vena cava 
 of the thorax and abdomen very much distended with 
 dark venous blood ; the stomach of more ample dimen- 
 sions than in the preceding ; the contents occupying the 
 larger arch of the stomach had undergone no perceptible 
 change ; the rest were better, but still coarsely, digested, 
 exhibiting strong traces of vegetable fibre. The large intes- 
 tines contained a mass only somewhat better concocted than 
 that in the stomach of the former. The lungs and heart 
 of this rabbit weighed seven drachms. 
 
 In the following rabbit, three quarters of an inch of the 
 par vagum, on each side, were cut out. This operation 
 was performed immediately after the preceding. Temper- 
 ature of the rabbit before experiment 104i. 
 
 At ten o'clock, A. M. the respiration was extremely la- 
 borious ; the temperature 100. From this hour the respi- 
 ration increased in difficulty till noon, at which period, in 
 extreme agonies, the rabbit jumped against the wall, and 
 expired. At this moment I separated the trachea, for the 
 purpose of transmitting air into the lungs, thinking that it 
 might revive the animal but it did not. On opening the 
 trachea a quantity of frothy matter flowed out, and con- 
 tinued to do so for the space of a quarter of an hour. The 
 quantity was sufficient to fill a table-spoon. 
 
 Dissection. The thoracic viscera of this rabbit exhi- 
 bited striking peculiarities. The lungs dense, no longer 
 crepitant, of a deep Modena hue, with circumscribed 
 patches of a much darker colour, entirely filled the cavity 
 of the thorax. The air cells on pressure effused a frothy 
 matter. The vena cava of the thorax and abdomen was 
 very much distended with black blood, The stomach 
 
AND ANIMAL LIFE. 227 
 
 was much larger than in the two preceding. The con- 
 tents were of a less firm consistence, but did not display 
 the same unaltered appearance as in the large arch of the 
 stomach of the former rabbit, being almost as much digest- 
 ed as the best concocted portion in the stomach of that 
 animal. The large intestines were in the same condition 
 as those of the preceding rabbit. The lungs and heart 
 weighed thirteen drachms and a half.* 
 
 EXPERIMENT II. 
 
 From the sudden death of the last rabbit, and from the 
 whole of the thoracic symptoms, I proposed, in this ex- 
 periment, to obviate the severity of the consequences by 
 dividing the trachea, and adapting to it a large brass tube, 
 to allow the atmospheric air to enter the lungs freely. The 
 three rabbits in this experiment were full grown, and ap- 
 peared equally healthy. After fasting for twenty-three 
 hours they were allowed to eat plentifully of cabbage leaves 
 five hours before the operation, immediately before which 
 a small quantity was again given. 
 
 Temperature of this rabbit 103. The trachea was divid- 
 ed, and the tube attached as described. About half an 
 inch of the par vagum on both sides was cut out. The 
 experiment commenced at one o'clock P. M. 
 
 At three o'clock the temperature was 104. The rabbit 
 breathed as easily as in the state of health. Tantillum 
 quidem hie secunda post sectionemfactam hora pati vide- 
 batur, utfemellam etiam ascenderet> atque cum ea coire 
 
 * To ascertain the weight of the lungs and heart of a rabbit 
 in health, the viscera were taken from two adult rabbits 
 that had been instantaneously killed. In the one they were 
 found to weigh two drachms and a half, in the other three 
 drachms and one scruple. 
 
 P 2 
 
THE LAWS OP ORGANIC 
 
 hand segmter conareiur. At half past four it seized with 
 avidity a cabbage leaf, but seemed very much oppressed 
 in the attempt to swallow. There was excited for some mi- 
 nutes a state of respiration not much unlike sneezing, and it 
 seemed, from the sound emitted, as if the tube was not 
 fully pervious. After a little time the rabbit resumed the 
 ordinary mode of breathing. At five o'clock the temper- 
 ature was 102 -. At seven o'clock the temperature was 
 100. The natural character of the respiration was un- 
 changed, but the animal appeared to be in considerable 
 pain. Its eyes were almost closed, the head raised up as 
 if to allow the air to enter the tube ; and its otherwise 
 motionless attitude, and occasional catches in its breathing, 
 indicated great uneasiness and suffering. Matter of a 
 sanious and frothy appearance exuded from the wound 
 in the neck. At nine o'clock the temperature was 99 ; the 
 rabbit was very dull and inanimate ; respiration as before, 
 the occasional catches more frequent. At eleven o'clock 
 the temperature was 99 1 ; the rabbit still dull and inani- 
 mate, refusing to eat. At one o'clock A. M. the temperature 
 was 103. The rabbit appeared more cheerful, and was 
 inclined to eat. It was left in this state till seven o'clock 
 that morning, at which time it seemed the same in every 
 external respect. An hour after this its temperature was 
 taken, and found to be 101 : the rabbit was then killed. 
 
 Dissection. The lungs did not collapse so perfectly as 
 ordinary, but were still crepitant, and of the natural ap- 
 pearance. The stomach, larger than usual, was filled with 
 a mass intermediate in every respect to the contents of the 
 two following ; the vegetable fibre and smell were still 
 evident. The contents of the large intestines differed little 
 from the natural state. The oesophagus was entirely filled 
 with imperfectly digested vegetable ; and this circumstance 
 
AND ANIMAL LIFE. 229 
 
 accounts for the oppression which the animal experienced 
 in the attempt to swallow what it had chewed. This or- 
 gan did not seem to have the power to propel the food 
 received, and consequently its great distention would 
 more or less compress the trachea, causing the symptoms 
 I have described on giving it food at half-past four. Great 
 inflammation and congestion were observed round the 
 wound, and the parietes of the thorax. 
 
 In the following rabbit the par vagum was divided on 
 both sides. Temperature 104. The trachea was not di- 
 vided. 
 
 At three o'clock the temperature was 100|. At half- 
 past four o'clock the rabbit received cabbage leaves, which 
 it voraciously seized ; but, after having taken a small quan- 
 tity, vomiting commenced, and continued, with slight in- 
 termissions, till a quarter to five, at which time the animal 
 died. The respiration had very much increased in diffi- 
 culty for two hours previous to its death. 
 
 Dissection. The lungs did not collapse on dividing the 
 parietes of the chest, but they were crepitant in almost 
 every part : they were almost as large again as the healthy 
 lungs. The superior surface was highly red, presenting 
 many small black points and slight discolorations ; the 
 inferior was marked with black patches. The greater 
 part of two lobes, in this situation, was in appearance like 
 the liver. 
 
 The condition of the heart was natural ; the veins of the 
 chest and abdomen were large, and much distended with 
 black blood ; the stomach much larger than usual ; the 
 principal part of the food appeared to have undergone no 
 change whatever ; the portion which was most acted upon 
 was still unaltered in its vegetable character, but was ra- 
 ther minutely divided. The contents of the large intes- 
 
230 THE LAWS OF ORGANIC 
 
 tines were coarser and less perfectly concocted than ordi- 
 nary. 
 
 In the following rabbit, the par vagum was divided on 
 one side only. Temperature 104. 
 
 Time. Temperature. Observations. 
 
 3 o'clock 105 Appearance healthy. 
 
 5, 1041 ditto. 
 
 7, 104J ditto. 
 9, 104 ditto. 
 
 11, 103 ditto. 
 
 1, A. M 103 ditto. 
 
 8, ditto, 104 ditto. 
 
 At eight o'clock in the morning the rabbit was killed. 
 
 Dissection. The lungs collapsed perfectly, but seemed 
 somewhat of a darker colour. The stomach, of a mode- 
 rate size, was filled with a mass that had lost the coarse 
 and chopped appearance of undigested vegetable, yet pre- 
 sented the vegetable smell, and here and there the vege- 
 table texture. The whole contents, at a superficial glance, 
 appeared homogeneous. The large intestines exhibited 
 the conditions of health. 
 
 EXPERIMENT III. 
 
 The three rabbits employed in this experiment were full 
 grown, healthy, and equally vigorous. They had fasted 
 twenty hours before they were fed with dandelion at eight 
 o'clock in the morning. The operations were performed 
 at half-past eight. In the following rabbit the trachea was 
 cut, and a tube attached to it, as in the preceding experi- 
 ment. Its temperature was 103. The nerves were left 
 intact.* 
 
 At two o'clock the temperature was 104| ; respiration 
 regular and easy. It seized with avidity the food which 
 was offered. From this time till ten o'clock at night there 
 
 * The trachea only in this and some other experiments was 
 cut, in order that we might estimate the influence of such a 
 serious operation on the digestive powers. 
 
AND ANIMAL LIFE. 
 
 was little particular to observe ; its appetite appeared as 
 keen as ever, but its respiration was occasionally labori- 
 ous. Its temperature was 104. At half -past seven the 
 following morning this rabbit was found dead, but was still 
 warm. 
 
 Dissection. The lungs were somewhat engorged, and 
 were of a bright Modena colour ; they collapsed but slight- 
 ly on opening the chest. The stomach was large, and its 
 contents were of two very opposite descriptions ; that oc- 
 cupying the cardiac portion was vegetable, slightly divided, 
 but not otherwise altered in appearance ; that of the pylo- 
 ric was well comminuted, and apparently homogeneous. 
 The contents of the large intestines were moderately well 
 concocted. 
 
 The trachea in the following rabbit was divided, and the 
 par vagum on one side only. Temperature of rabbit 105. 
 
 At two o'clock the temperature was 104 ; respiration 
 natural ; great avidity for food. At this time the rabbit 
 alias ascendere sospius conabatur, et, quanguam hebetior 
 erat, nihilommus blandiendo variis modis salacitatis spe- 
 ciem reprccsentabat. This is a phenomenon I cannot in 
 the least account for. A gentleman was with me when I 
 observed the same in Experiment II. I am persuaded 
 that it does not arise from the vigour of the animal, nor 
 from the natural impulse of the feeling ; for, in the present 
 instance, the first selected was a very fine male rabbit, and 
 it very frequently approached, without any discrimination 
 of sex or age, the individuals among which it was placed. 
 It has never occurred when the trachea only was cut, and, 
 since it has happened in these two cases in which the par 
 vagum was divided, it would seem to depend on some de- 
 rangement of the cerebellic system. But, as it is my in- 
 
THE LAWS OF ORGANIC 
 
 tention to state facts and not hypotheses, I shall leave 
 the reader to form his own judgment on this subject. 
 At ten o'clock at night the rabbit appeared as usual, and 
 was disposed to eat. At half-past seven o'clock next morn- 
 ing its breathing was laborious, and it refused to eat. The 
 temperature was 98. At this time it was killed. 
 
 Dissection. On opening the chest the lungs collapsed, 
 arid were of a perfectly healthy appearance, and crepitarit 
 throughout. The contents of the stomach were homoge- 
 neous, and of a very soft consistence. In different parts 
 of the stomach undigested vegetable was evident ; but the 
 whole mass was as well digested as the pyloric portion of 
 the preceding, but scarcely equal to that of the following. 
 The contents of the large intestines were fluid ; but from 
 this circumstance no inference can be drawn, as the intes- 
 tines were in a state of high inflammation, and were agglu- 
 tinated in several situations. 
 
 The trachea of this rabbit was divided, and the tube at- 
 tached as in the preceding ; about half an inch of the par 
 vagum, on each side, was cut out. Temperature of the 
 rabbit 104. At two o'clock the rabbit was breathing as 
 in the state of health. At ten o'clock the respiration had 
 become slightly laborious and hurried. Its temperature 
 was 982. It died in about seven minutes after I had as- 
 certained its temperature. The cause of its sudden death 
 I could not account for. It did not appear particularly op- 
 pressed before the introduction of the thermometer into 
 the rectum. The chest was immediately opened, and pre- 
 sented the following appearances. 
 
 Dissection. The lungs collapsed on opening the chest ; 
 they were somewhat of a darker colour than natural, but 
 did not present any traces of inflammation, nor did we ob- 
 serve any dark patches ; they were of the usual size, and 
 
AND ANIMAL LIFE. 233 
 
 crepitant throughout. The liver was very large, and di- 
 minished the capacity of the thorax. The stomach was of 
 the usual dimension, and contained a small quantity of air. 
 The contents appeared homogeneous ; but when examin- 
 ed, there were here and there the remains of vegetable fibre ; 
 yet the whole mass was minutely divided, and exhibited a 
 more advanced progress towards perfect digestion than 
 that of the two preceding. The contents of the large in- 
 testines seemed to be well concocted ; the small intestines 
 were distended with air to a great extent. 
 
 EXPERIMENT IV. 
 
 In this rabbit the trachea only was divided. Tempera- 
 ture 105. At five o'clock the respiration was natural, and 
 the rabbit was inclined to eat. At seven it appeared per- 
 fectly well, and had great avidity for food ; in ten minutes 
 after it jumped out of the box in which it was kept, ran 
 once half round a large room, and in a few seconds expired 
 in struggles. The frequency and suddenness of this cir- 
 cumstance was mortifying, as it interfered with the train of 
 experiments, but more so from my not being able to account 
 for it. It is so natural for the mind to attribute extraor- 
 dinary effects to extraordinary causes, that I did not ima- 
 gine, till the present instance occurred, that the phenome- 
 iion might arise from the stoppage of the tube, which I 
 found to be the case ; and the knowledge of this fact 
 enabled me to save the life of the following rabbit ; and it 
 also accounts for the previous accidents of the same kind. 
 The tube is so liable to become partly or completely im- 
 pervious, that the experiment is rendered delicate, and 
 sometimes unsatisfactory. 
 
 Dissection. The lungs were somewhat congested, of a 
 deeper colour than natural, and, although perfectly crepi- 
 tant, did not collapse so completely as in the former in- 
 stance. The stomach, of its usual size, was filled with 
 
234 THE LAWS OF ORGANIC 
 
 imperfectly digested food, which exhibited, especially to- 
 wards the cardiac extremity, many pieces of unaltered 
 vegetables; towards the pyloric, though somewhat better 
 digested, it was by no means so much so as in the latter 
 rabbit. The contents of the large intestines appeared per- 
 fectly concocted. 
 
 The trachea of the following rabbit was not divid- 
 ed till the difficulty of breathing was obvious. About 
 half an inch of the par vagum on both sides was cut out. 
 Temperature 102. At five o'clock the respiration dif- 
 fered slightly from the state of health : the rabbit was 
 disposed to eat. At seven o'clock the respiration easy. 
 At eleven it was difficult. At one, A. M. the rabbit ran 
 across the room, and struggled, as the preceding had 
 done, at seven. Perceiving this, and believing it to origi- 
 nate from the same cause, I passed a probe down the tube 
 attached to the trachea, and had the satisfaction of seeing 
 the animal revive and breathe with almost the ease and regu- 
 larity of health. At eight o'clock in the morning the animal 
 seemed quite worn out ; its breathing was rather hurried 
 and weak, but not particularly laborious. The rabbit 
 reclined partly on its side ; and, when raised up, a small 
 quantity of mucus was observed to ascend in the brass 
 tube, accompanied by a sound similar to what is heard on 
 applying the ear to the chest of a phthisical patient in 
 whose lungs large cavities exist. At this time it was killed. 
 The temperature was taken immediately after death, and 
 found to be 105. 
 
 Dissection. On opening the thorax the lungs collapsed, 
 and were of a healthy appearance in every part except the 
 posterior lobe on the left side, which was of a much darker 
 colour than the rest; they were throughout crepitant. 
 The stomach, of a small size, was filled with a perfectly 
 homogeneous matter of a soft consistence, and which had 
 
AND ANIMAL LIFE. 235 
 
 entirely lost the characters of vegetable food. The con- 
 tents of the larger intestines were more completely con- 
 cocted than any that I have observed in the whole series 
 of these experiments. The neck of the animal was dis- 
 sected after having examined the thoracic and abdominal 
 cavities, and the divided ends of the par vagum on each 
 side were readily discovered. 
 
 The two rabbits in this experiment were seven weeks 
 old. They had partaken of a small quantity of dandelion 
 at one o'clock, p. M. ; the operation was commenced an 
 hour afterwards. 
 
 CCLIIL The preceding experiments are con- 
 elusive and important in their character. We 
 have now no longer any uncertainty concern- 
 ing the principal function of the eighth pair 
 of nerves ; nor are we perplexed in endeavour- 
 ing to explain the consequences which follow 
 their division. In Chapter III. I endeavoured 
 to show the fallacies in the reasoning of WIL- 
 SON PHILIP, and stated that the beneficial in- 
 fluence of galvanism was not to be attributed to 
 any similarity or identity with the nervous fluid, 
 but to its general stimulating properties ; and I 
 have by the present experiments shown, if a tube 
 be attached to the divided trachea, although the 
 nerves be cut, that digestion goes on as well as 
 when the trachea alone is divided. From such 
 facts, which it is unnecessary to multiply, we 
 prove, that whatever disorders the proper oxy ve- 
 nation of the blood, or disturbs its distribution, 
 deranges the function of digestion ; and, still fur- 
 
236 THE LAWS OF ORGANIC 
 
 ther, that whatever maintains or re-establishes the 
 regular action of the thoracic viscera, maintains or 
 re-establishes the function of digestion, not because 
 the nerves are affected by such changes, but be- 
 cause the secretory organs depend on these con- 
 ditions of the blood. 
 
 CCLIV. If from a similarity of effects we are 
 authorised to infer a similarity of causes, we may 
 state that the admission of air into the lungs by 
 means of a brass tube is identical with galvanism 
 and the nervous fluid ; but those who support 
 the opinion that the two latter are the same or 
 similar, will be unwilling to allow this conclu- 
 sion, because we know that atmospheric air is 
 not galvanism, nor does it possess any properties 
 like those ascribed to the nervous fluid. 
 
 CCLV. In rabbit third, Experiment I. it 
 is stated that the lungs and heart were about 
 four times as heavy as those belonging to the 
 first ; and these results are in harmony with the 
 symptoms observed during life. In the one, res- 
 piration was performed with facility; in the other, 
 the breathing became difficult immediately after 
 the operation, and the urgency continued to in- 
 crease till death, which happened in four hours 
 after the excision of a part of the nerves. The 
 additional density and increased size of the lungs 
 and heart, and the great distention of the tho- 
 racic and abdominal veins, explain the cause of 
 death and the phenomena remarked previous to 
 this event. 
 
AND ANIMAL LIFE. 237 
 
 CCLVI. When the par vagum was divided on 
 both sides of the neck,* the aperture of the glottis 
 was much diminished from the paralysis of its 
 muscles ; and this accounts for the difficulty of 
 breathing which almost directly succeeds the 
 operation. Although the ingress of air is, in 
 a great measure, prevented, yet the blood re- 
 turns for some time to the heart and lungs as in 
 health ; but when it arrives there it is impeded 
 in its circulation, nor does it undergo the neces- 
 sary changes ; the consequence of which is, that 
 it gradually accumulates, and ultimately renders 
 inefficient for the continuance of life, the small 
 quantity of air allowed to pass through the les- 
 sened aperture of the glottis. If this rabbit had 
 lived a little longer, we should have observed a 
 great diminution of temperature. In the second 
 of the same experiment, the thoracic disorders 
 were intermediate in degree between the first 
 and third, and yet its temperature was reduced 
 12 ; and this effect is in harmony with the first 
 general principle, viz. that animal heat is not in the 
 direct ratio of the quantity of oxygen inhaled, but 
 in the inverse ratio of the quantity of blood ex- 
 posed to this principle. 
 
 EXPERIMENT V. 
 
 The two rabbits employed in this experiment were be- 
 tween two and three months old, apparently healthy. 
 
 * Vide. Appendix. 
 
238 THE LAWS OF ORGANIC 
 
 They had fasted fifteen hours, when they were fed at 
 seven o'clock, A. M. The experiment commenced at eight 
 o'clock. The par vagum on each side was tied in the fol- 
 lowing rabbit. Temperature before experiment 103. The 
 animal cried immediately on the nerves being tied, and 
 respiration was difficult from the commencement. Vomit- 
 ing and great difficulty of breathing were very oppressive 
 directly after the operation, and the former continued so 
 for a quarter of an hour ; the latter increased in urgency 
 throughout the experiment. At eleven o'clock the tempe- 
 rature was 99| ; respiration very difficult. The animal 
 displayed an avidity for food, but had not the power of 
 eating. At one o'clock, respiration short and laborious. I 
 attempted to take the temperature, but, from the difficulty 
 of breathing, it was impossible, with safety to the life of 
 the animal. In half an hour after this time it died. Its 
 temperature was found to be 93|, taken when insensible, 
 but not dead. 
 
 Dissection. The lungs did not collapse on opening the 
 thorax, were scarcely crepitant in any part, and were simi- 
 lar, in almost every respect, with the exception of here and 
 there a few light points, to a mass of coagulated venous 
 blood. The veins of the thorax arid abdomen were dis- 
 tended with black blood. The stomach, of a moderate 
 size, was filled with food, of which that part contained in 
 the large extremity appeared not in the least acted upon, 
 while that in the small was rather more digested. The 
 contents of the large intestines were natural. The thoracic 
 viscera weighed 4 drachms and a-hdlf. 
 
 The par vagum on each side was tied in the following rab- 
 bit. Temperature 103. Difficulty of breathing commenced 
 immediately, but was not so urgent as in the preceding ani- 
 mal. At eleven o'clock respiration laborious ; temperature 
 
AND ANIMAL LIFE. 239 
 
 was not taken, from the struggles which the attempt occa- 
 sioned. A few minutes after the death of the foregoing 
 rabbit it was on the point of expiring, which induced me 
 to kill it. Temperature 91 1, taken when insensible but 
 not dead. 
 
 Dissection. The lungs were precisely in the same state 
 as in the preceding rabbit ; and also the veins in the tho- 
 racic and abdominal cavities. The stomach was filled with 
 food, of which that portion contained in the large extre- 
 mity appeared to be vegetable quite unchanged ; that part 
 in contact with the mucous surface was more minutely 
 divided than the rest. The contents of the large intestines 
 were natural. The livers in both these rabbits were tuber- 
 culated. The thoracic viscera weighed four drachms and 
 a-half. 
 
 CCLV1I. It had been remarked by HALLER 
 and BICHAT that respiration was extremely dif- 
 ficult in cases in which the par vagum was di- 
 vided ; but we were not aware of the cause of 
 this till the decisive experiments of LEGALLOIS, 
 and those which I have performed, prove, that 
 dyspnoea, impeded or obstructed digestion, 
 enlargement of the heart, congestion and disease 
 of the lungs, distended state of the internal veins, 
 and diminution of temperature, are readily 
 prevented by dividing the trachea, and attaching 
 a tube to it at the time that the nerves are cut. 
 
 CCLVIII. For the purpose of observing with 
 more accuracy the results of the different experi- 
 ments, the rabbits were placed under my own 
 immediate eye, in a room to which they were 
 
24)0 THE LAWS OF ORGANIC 
 
 strangers. On this account they generally be- 
 came dull and inanimate, and I found this to be 
 the case with others which had undergone no 
 operation. When removed to their old abode 
 they ran about with their accustomed cheerful- 
 ness. Mental depression influences the diges- 
 tive powers of a rabbit as well as the more com- 
 plex functions of an intellectual being. I men- 
 tion this circumstance, as I am convinced that it 
 ought not to be neglected in experiments which 
 are instituted for the purpose of estimating the 
 value of any single organic law in regard to the 
 function of digestion or any of the secretions of 
 the system. 
 
AND ANIMAL LIFE. 241 
 
 CHAP. XT. 
 
 The Influence of Narcotics on the Generation of 
 Animal Heat and the Digestive Powers. 
 
 CCLIX. IN undertaking the present subject, 
 it is not my intention to investigate the indi- 
 vidual properties of the different narcotics, the 
 consideration of which would occupy considerable 
 time, and would necessarily exclude from this 
 book other topics more directly bearing on the 
 general principles expounded. Opium, whether 
 regarded as a medicine or poison, is more im- 
 portant and interesting than any included in the 
 general class of these substances, and, on this ac- 
 count, I shall select it for careful but general ex- 
 amination. 
 
 CCLX. From the variety of effects conse- 
 sequent on the exhibition of opium, much di- 
 versity of opinion exists concerning its true 
 action. Some are disposed to consider it as a 
 sedative, others as a stimulant. Those who sup- 
 port the former quality adduce the well known 
 symptoms of somnolence, prostration of muscular 
 power, insensibility to external and internal 
 agents, and the occasionally weak or slow con- 
 tractions of the heart. But, on the other hand, 
 
 Q 
 
THE LAWS OF ORGANIC 
 
 those who assert that it is a direct stimulant, lay 
 great stress, and with justice, on the more fre- 
 quent occurrence of excited action, such as the 
 forcible contractions of the heart, strong and 
 frequent pulsations of the arteries, and increased 
 temperature, displayed occasionally in the flow 
 of perspiration or heat of surface. 
 
 Some individuals entertain opinions less ex- 
 clusive in their character, and regard opium as 
 possessing both these properties. The stimulant 
 effects, they say, arise from the smallness of the 
 dose, and the sedative from an excessive quanti- 
 ty. This explanation is consistent with certain 
 facts, but is far from being satisfactory, when ap- 
 plied to the different phenomena of the system, 
 originating from the influence of opium. 
 
 CCLXI. Our ideas concerning the charac- 
 ters which constitute a sedative or stimulant, are 
 neither exact nor precise, and, until we have more 
 definite conceptions of these characters, we shall 
 continue to dispute about the action of opium. 
 If a sedative be defined to be a power that de- 
 presses the mental and corporeal faculties, evinced 
 by the incapability or insensibility of the mind, 
 and a diminution of the contractions of the heart ; 
 and if a stimulant be defined to be an agent which 
 excites the intellectual and physical endowments 
 of the system, as indicated by an unusual flow of 
 animal spirits, and increase of muscular force, we 
 are fully prepared to examine the merits of those 
 
AND ANIMAL LIFE. 243 
 
 theories proposed to solve the difficulties of the 
 present subject. 
 
 CCLXIL If the above definitions were consi- 
 dered correct, they would be fatal to the views of 
 those who assert that opium is a sedative or sti- 
 mulant, for, in the greater number of instances 
 in which the former property is exhibited, the 
 action of the heart is augmented; and when the 
 latter is supposed to be present, from the great 
 vigour exhibited by the heart and arterial system, 
 the faculties of the mind are depressed or incapa- 
 citated from performing their ordinary functions. 
 It is, therefore, manifest that contradictions and 
 inconsistencies exist in the various opinions 
 brought forward, 
 
 CCLXIII. Experiments and observations will 
 probably enable me to explain the action of nar- 
 cotics on the animal economy, or, at least, to pre- 
 sent views that apply more generally to the ef- 
 fects which succeed their exhibition. The dif- 
 ferent organs of the body are variously consti- 
 tuted, and the functions which they have to dis- 
 charge possess neither the same delicacy nor ob- 
 ject. We have organs whose office it is to con- 
 tract, secrete, or to develope the intellectual 
 powers ; and as these are in every respect so dif- 
 ferently formed, can we for a moment imagine, 
 although parts composing one great system, thai 
 they will be equally influenced by the same ge- 
 neral agent ? It is as reasonable to suppose that 
 
 Q 2 
 
244 ' THE LAWS OF ORGANIC 
 
 the eye will be affected by what is painful to the 
 ear, as that these organs will suffer to the same 
 extent by the general operation of opium or 
 any other agent. 
 
 CCLXIV. The heart and the brain reciprocally 
 and almost immediately act on each other. If the 
 former be excited, it almost directly communi- 
 cates to the brain a portion of the energy which 
 it displays ; and if the latter be deranged or dis- 
 eased by congestion or external injuries, it dis- 
 orders the action of the heart, by perverting the 
 regularity of the respiratory functions. By ren- 
 dering the respirations less frequent or complete,, 
 the qualities of the blood are deteriorated ; and as 
 the motion of the heart depends on these, it will 
 necessarily be implicated in those conditions of the 
 cerebrum by which the respiration is deranged. 
 
 CCLXV. When a small quantity of opium has 
 been taken, it is absorbed, and carried by the cir- 
 culation to every part of the body. The heart is 
 increased in its contractions, because its nerves 
 are directly stimulated ; and the faculties of the 
 mind are also excited, exhibiting a state of simple 
 exhilaration, or delightful reverie, from the ope- 
 ration of the same cause upon the brain. If a 
 still larger quantity be taken, the mental powers 
 are still more disturbed, showing the sedative ef- 
 fects of opium, such as insensibility to impres- 
 sions, or stupor, accompanied by stertorous or 
 interrupted respiration ; but while the sangui- 
 
AND ANIMAL LIFE. 245 
 
 neons fluid occasions these consequences in the 
 delicate and nervous structure of the brain, it still 
 remains for some time a stimulus to the heart, 
 because this is differently organized. But it not 
 unusually happens that the dose is sufficiently 
 great to enfeeble the motions of this organ, at 
 the same time that it disorders the functions of 
 the brain. 
 
 CCLXVI. I have observed in many experi- 
 ments performed on rabbits, that a small quanti- 
 ty of opium, in the greater number of instances, 
 augments the action of the heart for a short pe- 
 riod, while a greater proportion almost imme- 
 diately diminishes the force and frequency of its 
 contractions. If such circumstances occur in an 
 animal made insensible, it is reasonable to sup- 
 pose that the same agent operates in a similar 
 manner upon the animal economy possessed of 
 its ordinary powers. 
 
 CCLXVII. When an individual or animal is 
 in a state of stupor, the breathing is irregular or 
 imperfect. This would seem to arise from the 
 blunted sensibility of the cerebrum to impressions com- 
 municated in health by the nerves belonging to the 
 function of respiration. M y experiments have been 
 made on rabbits ; and I have observed, when these 
 were stupified, that they appear for a while to 
 forget to breathe y until the accumulation of blood in 
 the lungs becomes painful 9 or the necessity of air im~ 
 perative. The sensation arising from one of these 
 
246 THE LAWS OF ORGANIC 
 
 causes is of an aggravated nature, and tends to 
 arouse the breathing for a moment. The animal 
 has sudden starts, and, after these, respires with 
 regularity for a few seconds, but soon returns to 
 its previous disordered condition. 
 
 CCLXVIII. The irregular, or interrupted mode 
 of respiration, tends to render imperfect the pro- 
 per oxygenation and distribution of the blood ; 
 and in accordance with these changes, we observe 
 that the animal heat is diminished. 
 
 I have made many experiments on this sub- 
 ject, and have invariably found that the temper- 
 ature is lessened as soon as the narcotic effects are 
 manifest. The two following experiments may 
 be regarded as affording a correct idea of the ge- 
 neral changes which succeed the exhibition of 
 opium. Thirty grains of this substance were in- 
 jected into the cellular tissue of the abdomen of 
 a full grown rabbit : its temperature before ex- 
 periment was 102. 
 
 Time Minutes. Temperature. Respirations. 
 
 40 96 30 per minute, 
 
 65 94| 33 
 
 105 93 33 
 
 160 96 40 
 
 215 96 40 
 
 295 98 More frequent. 
 
 7 hours. 100 ditto. 
 
 13 ditto. 102 ditto. 
 
 Rabbit full grown ; colour white ; temperature 102. 
 About five grains of opium were injected as in the pre- 
 
AND ANIMAL LIFE. 247 
 
 ceding case, and the effects were equally well marked 
 The experiment commenced at eight o'clock A. M. 
 
 Time. Temp. Observations. 
 
 11 o'clock A M. 92 Affected with frequent and ge- 
 neral spasms ; paralysis of the 
 lower extremites, and pro- 
 found stupor present. 
 
 1 do. P. M. 91 Spasms less severe, paralysis as 
 before. 
 
 past 2. 91 Little alteration. 
 
 I past 3. 90i Ditto. 
 
 5 o'clock 89 
 
 At this time the rabbit appeared very cold, and 
 was evidently much worse. For the purpose of 
 reviving it, I placed it near the fire, and, occa- 
 sionally with my warm hand, endeavoured to 
 stimulate the external circulation, by gently rub- 
 bing the surface of the body. These means gra- 
 dually restored the animal to invigorated life. 
 At 11 o'clock, P. M. its temperature had risen to 
 103: scarcely any remains of paralysis. The 
 rabbit was not altogether so lively as in health, 
 but was inclined to eat, and partook of the food 
 which was presented. It ultimately completely 
 recovered. I have already stated that the eye is 
 dull and languid in those cases in which the ten> 
 perature is lowered and the blood imperfectly 
 oxygenated. In the present rabbit, I had a 
 good opportunity of verifying the correctness 
 of the statement. It is well known that 
 white rabbits have the iris of a red colour. 
 During the experiment I was surprised to find 
 that this entirely disappeared. If viewed at a 
 
248 THE LAWS OF ORGANIC 
 
 short distance, it seemed black, but when exa- 
 mined close it was discovered to be of a dirty 
 brown ; and this colour continued, with slight 
 alterations, for many hours after it had recovered 
 the faculty of generating the usual quantity of 
 animal heat. This fact is important, as it shows 
 that the most delicate part of the capillary system 
 is affected long after the thoracic organs have re- 
 gained their general vigour. The eye may be consi- 
 dered an index of the condition of the whole capil- 
 lary system, and, therefore, it is important, as it 
 teaches that the production of animal heat should 
 be carefully attended to long after its re-esta- 
 blishment, because the unfavourable effects, oc- 
 casioned by the circulation of improper blood, are 
 not removed so soon as we might imagine. 
 
 The number of respirations is extremely vari- 
 able. I have often counted 20 and 25 in one mi- 
 nute, and, almost immediately after, double this 
 number. The cause of this was explained in 
 CCLXVII. 
 
 CCLXIX. The respiratory function is disor- 
 dered by the affection of the brain, and, as it re- 
 covers its ordinary sensibility, the proper oxyge- 
 nation and circulation of the blood are establish- 
 ed. But if the narcotic effects increase, the ne- 
 cessary conditions of the sanguineous fluid are no 
 longer maintained ; the extremities become cold, 
 the surface of the body discoloured, the face tu- 
 mefied, and the temperature diminished. These 
 are the consequences of deranged respiration. 
 
AND ANIMAL LIFE. 24Q 
 
 The blood which is circulated at this time is 
 dark, and but slightly stimulating. The con- 
 tractions of the heart, and the vigour of the arte- 
 rial system, occasionally observed under these 
 circumstances, are not excited by the oxygenated 
 properties of the blood as in health, but are con- 
 tinued in action, for a time, by the diffused and 
 stimulating properties of the opium. If it were 
 possible to withdraw from the system the qualities 
 which this poison has bestowed, it is not improbable 
 that this deduction would immediately destroy the 
 powers of life, because the blood would be deficient 
 in its natural stimulus, then indispensable to promote 
 its distribution. 
 
 CCLXX. If we suppose a given quantity of 
 opium to be received into the system, whether 
 from the stomach, cellular tissue, or rectum, it is 
 gradually absorbed, and, in proportion as this is 
 effected, the sensorial powers are disturbed, and 
 this disorder is communicated to the respiratory 
 function, so that, while the former are directly, 
 and the latter indirectly, influenced by the action 
 of opium, the heart is frequently stimulated to 
 augmented action by the same agent ; but as the 
 blood is deteriorated for want of those conditions 
 by which it is perfectly oxygenated, and as its 
 venous qualities accumulate, the artificial stimu- 
 lus of the opium, if it does not act as a sedative 
 from its inordinate quantity, is overcome by 
 the sedative qualities of the blood increasing 
 
250 THE LAWS OF ORGANIC 
 
 to a much greater extent the severe symptoms, 
 such as diminution of sensibility and muscular 
 motion. 
 
 CCLXXI. In those individuals who have died 
 from the effects of opium, we remark no traces of 
 inflammation ; nor should we expect to find such, 
 if we consider that inflammation can arise only 
 from two general causes, viz. such as destroy 
 or act violently on a part to which they are applied, 
 or such as directly or indirectly tend to increase the 
 oxygenated properties of the blood. The influence 
 of opium lessens the natural stimulus of the 
 blood, and acts principally on the nerves, increas- 
 ing or diminishing the action of the organ to 
 which they are distributed, and does not injure 
 the texture like the class of acrid substances. 
 
 CCLXXI I. Guided by the views already de- 
 veloped, it is not difficult to explain the different 
 appearances observed in the examination of those 
 who have died from the effects of opium. The 
 lungs are found congested, occasionally present- 
 ing large dark patches ; the heart full of black 
 blood, or its vessels much engorged ; the sto- 
 mach, although not inflamed, exhibits greater 
 vascularity than usual, and the veins of the tho- 
 rax, abdomen, and brain are often found dis- 
 tended with dark venous blood. From the first 
 stage of the narcotic effect, the sanguineous fluid 
 has gradually lost its vital powers, assuming the 
 character of venous ; and when the heart ceases to 
 
AND ANIMAL LIFE. 251 
 
 be excited by the opium, its motions are too much 
 enfeebled to propel the fluid to the distant parts 
 of the body, and, therefore, they are Insufficient 
 to counterbalance the quantity of venous blood which 
 returns to the chest. From this cause the blood 
 continues to accumulate in the internal cavities, 
 from the first symptom of depression till the 
 complete extinction of life. 
 
 CCLXXIII. Without entering into a detailed 
 account of the principles or plans of cure employ- 
 ed in cases of poisoning from opium, I shall endea- 
 vour to show the benefit that will be derived from 
 attending to certain remedial measures suggested 
 by the preceding observations. Vomiting is always 
 recommended at the development of the first bad 
 symptoms, for the purpose of removing the dele- 
 terious substance from the stomach, and thereby 
 arresting absorption ; but this effect has never 
 been regarded in any other light than as ejecting 
 the poisonous drug. If we keep in view what 
 has already been stated in the foregoing pages, 
 viz. that the internal organs are congested, a fact 
 supported by every case related by ORFILA,* we 
 shall perceive the force of the following reason- 
 ing, and the correctness of the principles esta- 
 blished in the present work- 
 By confining vomiting to the simple expul- 
 sion of the contents of the stomach, we lose the 
 
 * Vide Chapter IV. Class IV. Des Poisons Narcotiques. 
 Traite des Poisons, Tom. II. 
 
252 THE LAWS OF OllGAXIC 
 
 most powerful agent that we possess for coun- 
 teracting the baneful consequences induced by 
 opium, I have proved by direct experiment on 
 myself and another gentleman, that whenever vo- 
 miting is promoted, the blood is immediately more 
 equally distributed throughout the system, and, 
 as a necessary sequence, that the temperature of 
 the body is increased, in accordance with the first 
 principle, viz. " that animal heat is not in the 
 direct ratio of the quantity of oxygen inhaled, but 
 in the inverse ratio of the quantity of blood ex- 
 posed to this principle''' 
 
 CCLXXIV. It is therefore advisable to em- 
 ploy vomiting in these cases as frequently as 
 possible ; it tends to relieve the congested lungs, 
 and allows the blood to undergo more perfect 
 changes, indispensable to overcome the injurious 
 influence of the poison and the highly venous 
 state of the blood. 
 
 CCLXXV. When an individual is in a sopo- 
 rose condition from the effects of opium, it is 
 recommended that he be kept continually walk- 
 ing, as if this action were beneficial beyond the 
 mere exercise of muscular power improving or 
 maintaining the circulation, and exciting the res- 
 piratory function, by keeping the mind awake to 
 the impressions made on the respiratory nerves 
 as explained in CCLXVII. If, instead of adhering 
 to these inefficient means, we promoted vomiting 
 by medicines whose operation is not preceded 
 
AND ANIMAL LIFE. 253 
 
 by nausea, which would augment the evil, and if 
 we placed the inferior half of the body in water as 
 warm as the individual can bear it, employing at 
 the same time almost constant friction, and if we 
 also applied a bladder of warm water to the pit of 
 the stomach, to lessen the congestion of blood in 
 this organ and the thoracic viscera, we should so 
 far equalize the circulation as to improve the 
 chemical changes of the sanguineous fluid ; and, 
 in proportion as we accomplished this object, we 
 should find that the powers which belong to or- 
 ganic and animal life readily return. 
 
 CCLXXVI. Depletion has occasionally been 
 resorted to in the treatment of poisoning from 
 opium, and has in some cases been found bene- 
 ficial. ORFILA, after making experiments on 
 this subject, draws several conclusions favourable 
 to its judicious employment, of which the follow- 
 ing is one : 
 
 " %do, Qu'elle a paru utile dans quelques cir- 
 " Constances, et meme qu'elle a suffi pour retablir 
 " des animaux qui auraient peri si on ne Pevit 
 " pas pratiquee.*" Depletion has been found 
 useful in the cold stage of intermittent fever, 
 because it takes off a part of the burden from the 
 Internal organs, and thereby permits the lungs to 
 oxygenate more completely the blood, which speedily 
 excites the action of the heart, the increased con- 
 tractions of which distribute the blood more gene- 
 
 * Ibid, p 248. Tom. II. 
 
254 THE LAWS OP ORGANIC 
 
 rally throughout the system. When the consti- 
 tution is labouring under the effects of opium, 
 we have internal congestion of a similar kind, 
 from a different cause, and to a less extent ; but, 
 if the remedy be beneficial on one occasion, it will 
 on another, if the only difference between the two 
 consist in the degree. 
 
 CCLXXVII. From observations contained in 
 the preceding pages, it is evident that animal heat 
 is diminished from congestion of the lungs and 
 internal organs, agreeably to the principles fully 
 stated in Chapter I. As this is demonstrated by 
 direct experiment, the other views so intimately 
 connected with these principles receive additional 
 support. 
 
 CCLXXVIII. Observing the diminution of 
 temperature and the irregularity in the distribution 
 of the blood, from the narcotic effects of opium, 
 it appeared to me probable that digestion would 
 also be retarded. I attempted to show, in Chapter 
 III., whenever animal heat was much lessened, 
 and the circulation of the blood much disorder- 
 ed, that these states were incompatible with the 
 secretion of gastric juice. The following experi- 
 ments prove that, whenever the same or similar 
 conditions of the sanguineous fluid exist, whether 
 from the division of the par vagum, the applica- 
 tion of cold, or the exhibition of opium, the same 
 or similar consequences succeed. 
 
AND ANIMAL LIFE. 255 
 
 EXPERIMENT I. 
 
 In this experiment, opium was injected into the cellular 
 membrane of the abdomen of a full grown rabbit. Before 
 the operation its temperature was 105. The experiment 
 was commenced at seven o'clock, A. M. 
 
 Time. Temperature. Respiration. 
 
 I to 10 o'clock, A. M. 105 
 * past 11, 98i 
 
 Cate a small ^ 
 
 1 past 12, 97 < quantity of 24 
 
 (vegetables.) 
 
 2 P. M. 97 48 more 
 
 lively. 
 
 past 3, 97 great inclina- 52 same. 
 
 tion to eat. 
 
 At this period it was killed, and another also which had 
 taken food at the same time, that we might with more cor- 
 rectness compare the influence of opium, 
 
 Dissection. Examination of the rabbit which had been 
 subjected to the effects of opium. The stomach was full, 
 containing a dark green vegetable mass, imperfectly con- 
 cocted. The contents of the large intestines did not ex- 
 hibit their ordinary changes ; they were rough, and rather 
 of a firm consistence ; the other viscera were healthy. 
 
 The stomach of the sound rabbit was less distended than 
 the other ; but the mass was less perfectly digested, aris- 
 ing apparently from recent vegetable food which it had 
 taken. The contents of the large intestines were smooth, 
 soft, and completely changed in their vegetable character. 
 
 EXPERIMENT II. 
 
 Opium injected as before. The rabbit full grown. Tem- 
 perature 104|. The experiment commenced at seven 
 o'clock, A. M. 
 
256 THE LAWS OF ORGANIC 
 
 Time. Temperature. Respirations. 
 
 i to 10 o'clock, A. M. 104 
 
 i past 11. 100^: 
 
 1 past 12. 98| 26 
 
 2 P. M. 98 44 more lively. 
 
 $ past 3, P. M. 101 J 48 great inclination 
 
 to eat. 
 
 The rabbit was killed at this time. 
 Dissection. The stomach was quite full of a bright 
 green mass, possessing the vegetable smell and fibre. The 
 contents of the larger intestines were less perfectly con- 
 cocted than usual. All the viscera appeared healthy. 
 The stomach of the second rabbit was much less distended, 
 and its contents were as well digested as those of the large 
 intestines of the preceding rabbit. The contents of the 
 large intestines were smooth and soft, and apparently well 
 concocted. 
 
 EXPERIMENT III. 
 
 Opium injected as before. Temperature of the rabbit 
 10%. The animal full grown. Experiment commenced 
 at half past eight o'clock, A. M. 
 
 Respirations. 
 
 24 
 40 
 44 
 40 
 
 Killed at this time. 
 
 Dissection. Stomach slightly distended with air. The 
 vegetables which it had taken before the experiment had 
 undergone scarcely any change. The contents were fibrous 
 and coarse, presenting a chopped appearance. The co- 
 lour, not uniform throughout, varied from a light to a 
 dark green. The contents of the large intestines were 
 
 Time. 
 
 Temperature. 
 
 10 o'clock, A. M. 
 
 102^ 
 
 past 11, 
 
 96| 
 
 i tO 1, P. M. 
 
 95 
 
 past 2, 
 
 96i 
 
 4 o'clock, 
 
 98 
 
AND ANIMAL LIFE. 257 
 
 rough, and by no means minutely divided as in those cases 
 in which digestion had gone on well. The lungs were 
 very much congested. The posterior surface exhibited 
 dark patches and effused blood. From these well mark- 
 ed appearances, it was not thought necessary to kill a 
 sound rabbit for the purpose of comparing the results. 
 
 EXPERIMENT IV. 
 
 The rabbit full grown. Temperature 103J . The ex- 
 periment commenced at half-past eight o'clock, A. M. Opi- 
 um injected as usual. 
 
 Time. Temperature. Respiration. 
 
 10 o'clock, A. M. 99F 
 
 past 11, 98; 44 
 
 i to 1 p. M. 100 64 
 
 1 past 2 100 40 
 
 4 o'clock 100 52 
 
 Killed at half-past four o'clock, p. M. 
 
 Dissection. The rabbits were not opened till ten o'clock 
 next morning. The stomach of the one which had taken 
 opium was very large, and slightly distended with air. 
 The cardiac and pyloric orifices exhibited a vegetable mass 
 of two different colours and states of digestion. At the 
 cardiac the vegetable was little if at all changed, of a dark 
 green colour, emitting a strong vegetable smell. The 
 whole was covered over with a coating of gastric juice. At 
 the pyloric extremity the vegetable had undergone a slight 
 change, the green colour had almost disappeared, and the 
 vegetable texture was less evident. The large intestines 
 were distended with vegetable matter, presenting a rough, 
 imperfectly concocted, appearance. The lungs were much 
 inflamed at their posterior surface ; the inferior parts of 
 the lobes were very much congested and discoloured. 
 
 The sound rabbit, which was killed at the sametime as 
 the preceding, was now opened. 
 
 R 
 
258 THE LAWS OF ORGANIC 
 
 Dissection. The stomach moderately distended with 
 air. The vegetable smell was slightly evident. The con- 
 tents of the cardiac and pyloric orifices were of the same 
 colour and consistence, and were minutely divided. The 
 large intestines were as full as those of the preceding rab- 
 bit ; but the digestive process had evidently produced great 
 alterations on the matter which they contained. The lungs 
 were a little more florid than usual. 
 
 These rabbits were fed at five o^clock, p. M. the day preced- 
 ing the experiment, and were again fed an hour before the 
 injection of the opium. They received no food afterwards. 
 
 CCLXXIX. It is unnecessary to multiply these 
 experiments to prove that digestion is impeded 
 when the temperature is lowered and the distri- 
 bution of the blood deranged. (( SFALLANZANI 
 observed that the snake digested food faster in 
 June, when the heat was at 821 and 83, than in 
 April when it was only 60; from whence he con- 
 cludes that heat assists digestion."* Similar ob- 
 servations are found in the works of many na- 
 turalists who have paid particular attention to 
 the influence of heat and cold on the powers of 
 digestion. In making these experiments, I lost 
 many rabbits from the operation of opium. It 
 sometimes produces violent spasms, and when 
 these occur soon after its exhibition the animals 
 very frequently die. It is difficult to proportion 
 the dose of the narcotic so as to produce the desired 
 
 * Observations on certain Parts of the Animal Economy, by 
 JOHN HUNTER, p. 395. 
 
AND ANIMAL LIFE. 259 
 
 effects, without endangering the life of the ani- 
 mal. The influence of opium in these instances 
 does not lessen the generation of animal heat, 
 nor disturb the respiratory function to the same 
 extent as the division of the par vagum in those 
 cases in which the tube is not inserted into the 
 trachea ; and in accordance with this difference 
 in degree, we observe that the changes in the 
 stomach and intestines are more complete, and 
 the lungs do not show the same traces of disease. 
 I have noted the state of the respiration at the time 
 when the animal temperature was taken ; but the 
 reader must not imagine that the number which is 
 given is to be considered as a criterion of the char- 
 acter of the respiration prevailing for more than a 
 few minutes or seconds, but merely as presenting 
 to the mind an idea of the irregularity of respira- 
 tion. Messrs HOLROYD and MURRAY kindly 
 assisted me in these experiments. 
 
 R 
 
260 THE LAWS OF ORGANIC 
 
 CHAP. XII. 
 
 The Causes which Influence the Action of the 
 Heart. 
 
 CCLXXX. INHERE are probably few subjects 
 concerning which a greater diversity of opinion 
 exists, than regarding the cause of the contrac- 
 tions of the heart, and the precise manner in 
 which these are influenced by chemical and 
 mechanical changes. HALLER and his partisans 
 endeavoured to shew that the contractions are to 
 be ascribed to a vis insita independent of the 
 nervous system. LEGALLOIS concludes, that the 
 heart derives its powers from the whole of the 
 spinal cord : WILSON PHILIP has proved that 
 this organ can act when the brain is removed 
 and the medulla oblongata is destroyed, a fact I 
 have repeatedly ascertained. In Experiment V. 
 page 48-9, the heart was found contracting 70 
 times per minute in a rabbit that had been in- 
 flated for an hour, in which neither brain nor 
 spinal cord was present* 
 
 CCLXXXI. In Chapter X. we gave a cursory 
 glance at the properties and office of the nervous 
 system, and, therefore, shall not occupy the pre- 
 sent pages in discussing the same point. The 
 irritability which has been supposed by HALLER 
 
AND ANIMAL LIFE. 261 
 
 to reside in and characterise muscular fibre is de- 
 rived from the nerves of motion and sensibility. 
 This power is very much modified by three 
 causes: 1. The quantity of nervous influence posses- 
 sed by an organ ; 2. The disposition of the muscular 
 fibres ; 3. The nature of the stimulus necessary to 
 develope it. The heart has been proved by SCARPA 
 to be endowed with innumerable nervous fibrillae, 
 not confined, as was imagined by SOEMMERING 
 and his predecessors, to the coats of the coronary 
 arteries, but, on the contrary, intimately blended 
 with the constitution of the fibre itself. If we 
 consider the quantity of nervous power bestowed 
 upon the heart by the sympathetic and par 
 vagum, the disposition of the fibres and cavities 
 of this organ, and, lastly, the energetic and con- 
 stant stimulus operating here, we shall under- 
 stand in what manner the contractions of an 
 organ may be influenced. 
 
 CCLXXXII. There were two objections op- 
 posed to the opinion of HALLER. The first ivas, 
 for what purpose did the heart receive nerves? and 
 the second, why was it influenced by strong emotions 
 of mind ? The first is a difficulty which was never 
 satisfactorily solved by HALLER, and the latter 
 is considered equally unanswerable by the op- 
 ponents to the vis insita of this physiologist. 
 Although I am fully persuaded that the con- 
 tractions of the heart are to be ascribed to the 
 nervous power distributed to the muscular fi- 
 
THE LAWS OF ORGANIC 
 
 bres of the organ, yet I do not consider that 
 this endowment explains the frequent and vio- 
 lent disturbance in the function of circulation 
 observed in the exciting or depressing effects of 
 passion. The abdominal viscera are said to be 
 excited or depressed by the direct agency of 
 mind, but the greater number of the illustrations 
 brought forward in support of this opinion are 
 not strengthened by any reasoning or facts that 
 may not consistently be referred to causes inter- 
 vening between the mental affection and the 
 abdominal derangement. The development of 
 views connected with this subject belongs to a 
 subsequent chapter, and, therefore, we shall defer 
 its consideration. 
 
 CCLXXXIII. WILSON PHILIP has satisfac- 
 torily proved, that the gradual removal of the 
 brain, and destruction of the spinal cord, have 
 little or no influence on the action of the heart ; 
 and yet it is evident, he observes, that it can be 
 powerfully affected through the brain and spinal 
 marrow by chemical and mechanical means. It 
 is also stated by him and others, that it is extra- 
 ordinary that the instantaneous destruction of 
 the brain arrests for a few seconds the pulsations 
 of the heart, since this organ continues its mo- 
 tions when the above nervous sources are entire- 
 ly removed. 
 
 CCLXXXI V. This and many similar pheno- 
 mena will, perhaps, become less mysterious by the 
 
AND ANIMAL LIFE. 263 
 
 following considerations and experiments. The 
 sensorium, from its magnitude and the activity of 
 its functions, must necessarily receive a great 
 quantity of blood ; and whatever tends abruptly to 
 disorder its free transmission from the brain and 
 its reception to this organ, will manifestly influence 
 the contractions of the heart. 
 
 CCLXXXV. When the brain is destroyed by 
 degrees, the heart is scarcely sensible of the 
 gradual loss of blood, or of the effects it in- 
 duces in the general sanguiferous system ; but 
 when the brain is instantaneously crushed, we 
 have other consequences. This operation gives 
 rise to three results, which go far to explain the 
 momentary cessation in the contractions of the 
 heart. 
 
 First, The blood which is propelled along the 
 arteries in its passage to the brain is suddenly 
 
 forced back upon the heart, or is stopped in its 
 course, and thereby prevents the circulation of the 
 next portion transmitted by the contractions of the 
 heart. 
 
 Second, The circulation of blood in the veins is 
 equally disturbed. When the nervous mass is sud- 
 denly compressed, the blood that was previously 
 
 jiowing regularly to the heart is sent either with 
 inordinate force, as it is in this direction alone it 
 can escape, or its circulation is completely stopped ; 
 it is probable that both conditions with modifications 
 occur. 
 
264 THE LAWS OF ORGANIC 
 
 Third, The blow which is given necessary to pro- 
 duce the desired effect shakes the zvhole system of 
 the animal. The circulation of blood in the larger 
 arteries and veins is for a moment retarded, if not 
 completely arrested. 
 
 CCLXXXVI. If the circumstances which 
 have now been stated be taken into considera- 
 tion, it must be acknowledged that the mystery 
 connected with the phenomenon, if not altoge- 
 ther unravelled, is nearly so ; and in reasoning 
 on the manner in which the heart recovers its 
 contractions, we shall find the present view ma- 
 terially supported. In a few seconds after the 
 blow, the heart commences to pulsate, at first 
 feebly, but in a few minutes with almost its 
 ordinary vigour. During the short period of 
 its inactivity, it is either gradually and almost 
 imperceptibly overcoming the burden by which 
 it is oppressed, or during this time the whole 
 sanguiferous system re-establishes its regular func- 
 tions, and therefore we have the contractions of 
 the heart as soon as the different relations exist- 
 ing between the various parts of this system are 
 restored. 
 
 CCLXXXVII. If it were owing to the sup- 
 pression or injury of the nervous influence, the 
 cessation ought to be rather of a permanent than 
 evanescent character, because one of the sup-, 
 posed sources of nervous power is destroyed. 
 
AND ANIMAL LIFE. 265 
 
 CCLXXXVIII. WILSON PBILIP has endea- 
 voured to ascertain in what manner the action 
 of the heart is influenced by the application of 
 cjiemical and mechanical agents applied to the 
 brain ; and he brings forward a great number of 
 experiments, which prove, that these occasionally 
 act powerfully on the motions of the heart. He 
 says, that these act through the nervous system. 
 I shall attempt to shew from his own experi- 
 ments, and from others which I have performed, 
 that it is more than probable that the effects are 
 communicated through the sanguiferous. 
 
 CCLXXXIX. In applying spirits of wine or 
 opium to a small portion of the brain, no effects, 
 he says, were produced ; but as soon as these 
 were diffused over a large surface, the action of 
 the heart was affected. If we augment the sur- 
 face to which one of these agents is applied, we 
 include in the same proportion a greater number 
 of absorbents or capillary vessels of what kind 
 soever, and therefore the action of this organ is 
 more liable to be influenced, because a greater 
 quantity of the stimulus or sedative is absorbed 
 and transmitted to the heart, on whose nerves 
 it produces its peculiar effects. The greater num- 
 ber of the subsequent experiments demonstrate 
 the correctness of this opinion. Regarding the 
 circulation as the medium of these agents, and 
 the heart as influenced by the matters which the 
 blood had absorbed during the circulation, I 
 
266 THE LAWS OF ORGANIC 
 
 stated to my friends who kindly assisted me, 
 that it was not improbable we should observe 
 the same results on employing chemical means, 
 in one instance, on a small portion of the brain, 
 if this were in the vicinity of the larger vessels 
 transmitting the blood to the chest, that we ob- 
 serve in another if the portion be much more 
 extensive and confined to the surface. To prove 
 the truth of this opinion, I had a small tube 
 made about three inches long ; the aperture of 
 the superior end was half an inch in diameter ; 
 that of the inferior, applied to the base of the 
 brain, was one-eighth of an inch. When this 
 tube was introduced, the smaller end was made 
 impervious, until it had reached the base, by a 
 slender piece of wood, in order to prevent the 
 brain from filling the tube, which it had previ- 
 ously done in some of my earliest experiments, a 
 circumstance which tended to retard absorption, 
 as the contents of the instrument had lost all con- 
 nexion with the brain, and become as inorganic 
 matter. Adult rabbits were employed in this 
 series of experiments. 
 
 EXPERIMENT I. 
 
 The animal being made insensible by a blow upon the 
 occiput, the chest was opened, that we might observe the 
 contractions of the heart ; and afterwards a small portion 
 of the skull-cap was removed, to allow the introduction of 
 the instrument. A few drops of prussic acid were then 
 
AND ANIMAL LIFE. 267 
 
 applied. The heart contracted, but with an enfeebled 
 motion, for 45 seconds, and then ceased, but recommenced 
 in eight or ten seconds, and continued to contract five or 
 six times per minute for the space of three minutes, at 
 which time it altogether ceased. 
 
 EXPERIMENT II. 
 
 The preparatory steps of the operation were the same as 
 in the preceding instance. A few drops of prussic acid were 
 applied. The contractions of the heart were less frequent, 
 but appeared stronger directly on the application of this 
 poison. The results were not very decisive. In three 
 minutes from the commencement, the contraction still 
 remaining, a few drops more were applied, and the heart 
 immediately became affected; in a few seconds it gave 
 scarcely a perceptible pulsation. 
 
 EXPERIMENT III. 
 
 The preparatory steps having been attended to, a few 
 drops of the spirits of wine were applied. The motions of 
 the heart were more frequent for a few seconds, but as 
 soon became slow. lufusum tabaci was then employed ; 
 the contractions were quickened for a few seconds, but 
 almost immediately became much slower. Prussic acid 
 was lastly applied ; and this, like the preceding agents, 
 seemed to quicken the contractions, but in a few seconds 
 after its application the heart ceased to pulsate. 
 
 EXPERIMENT IV. 
 
 In this experiment infusum tabaci was employed first. 
 On its application the motions of the heart became almost 
 instantaneously slow ; they were previously strong and fre- 
 quent. While the contractions of the heart were feeble and 
 
268 THE LAWS OF O11GAN1C 
 
 slow, a few drops of alcohol were applied, which imme- 
 diately increased their frequency. 
 
 EXPERIMENT V. 
 
 Opium was applied first in this experiment. The con- 
 tractions of the heart became immediately rapid and irre- 
 gular, and continued for 20 seconds ; in 10 seconds more 
 they became slow, and were observed to be in this state for 
 40 seconds, at which time spirits of wine were applied, but 
 did not appear to produce any very obvious change, except 
 that the motions were converted from their former irregu- 
 lar character into one somewhat undulatory. 
 
 EXPERIMENT VI. 
 
 In this experiment prussic acid was applied first. In 
 80 seconds from the application the heart had almost ceased 
 to contract. Alcohol and opium were afterwards em- 
 ployed, but did not produce any obvious effects. 
 
 To show still more satisfactorily that the nervous sys- 
 tem has little, if any influence, in transmitting the effects 
 of the different agents to the heart, the subsequent experi- 
 ments were performed. If this can be shown, it necessarily 
 follows, that the small or extensive surface, alluded to by 
 WILSON PHILIP, is to be considered as merely presenting 
 different degrees of facility for the absorption of what is 
 applied to the brain. 
 
 EXPERIMENT VII. 
 
 The animal being made insensible, we cut down upon 
 the lumbar vertebrae ; and, having separated two of them, 
 a heated iron was passed from this point as far as the cer- 
 vical, and was allowed to remain there during the experi- 
 ment. The parietes of the abdomen were then divided 
 
AND A^ 7 IMAL LIFE. 269 
 
 immediately beneath the diaphragm, in two opposite direc- 
 tions, until the scalpel touched the two sides of the spine, 
 for the purpose of destroying all lateral connexion. When 
 this operation was finished the bowels were removed, and 
 a few drops of the spirits of wine were applied to the vena 
 cava immediately above the pelvis. Before the application 
 of these the beatings of the heart were almost imperceptible, 
 but in a little less than a minute they acquired compara- 
 tive frequency and force for about 40 seconds. 
 
 EXPERIMENT VIIL 
 
 The animal being made insensible, the chest was laid 
 open, that we might observe the motions of the heart. 
 The jugular vein was then opened, and two drops of prus- 
 sic acid were introduced through a blow -pipe ; the con- 
 tractions of the heart instantly ceased. I have performed 
 this experiment several times; the results were always 
 evident, but never so obvious as in this instance. 
 
 EXPERIMENT IX. 
 
 In this experiment it was intended that the brain should 
 have been removed and the spinal cord destroyed. The 
 former was accomplished with a greater loss of blood than 
 usually occurs, owing to an accident attending one of the 
 ligatures ; and two of the lumbar vertebrae were separated 
 in order to introduce the heated wire ; but every wire we 
 had provided was found too large ; therefore, in this expe- 
 riment, the brain alone was removed. The chest being 
 opened, as before, an aperture was made in the abdomen 
 to allow the operator to lay aside the intestines. A few 
 drops of the spirits of wine were applied to the vena cava, 
 as in Experiment VII. ; the heart, for a few seconds, had 
 its motions accelerated, but these, in a few minutes, com- 
 pletely ceased. 
 
270 THE LAWS OF ORGANIC 
 
 EXPERIMENT X. 
 
 This rabbit was decapitated, and the spinal cord was 
 destroyed by means of a heated wire. A few drops of the 
 spirits of wine were applied to the vena cava, as in the 
 above case. The contractions of the heart were quickened, 
 and, after a few seconds, when the increased action had 
 subsided, a few drops more were applied to the vena cava 
 immediately before it enters the thorax : the contractions 
 of the heart were again affected, as in the first instance. 
 
 CCXC. The above experiments prove, that 
 the extent of surface is to be considered as 
 merely facilitating absorption, and not as pre- 
 senting a greater mass of the nervous system to 
 the influence of the agents we employ. If we 
 diminish the surface and increase the facili- 
 ties of absorption by applying the materials near 
 the large veins at the base of the brain, we have 
 effects equally well marked as when we occupy 
 an extensive surface of the organ. WILSON PHI- 
 LIP observes, " It is evident that the heart not 
 being subject to stimuli, whose action is con- 
 fined to a small portion of this organ, and being 
 equally affected through all parts of it, must 
 render it much less subject to irregular action. 7 '* 
 If the heart be subject to the whole brain, it will 
 be capable of being excited or depressed by a 
 concentration of influence to any single part ; and 
 this was proved in a very satisfactory manner by 
 some of the preceding experiments, In Experi- 
 
 * WILSON PHILIP, p. 117. 
 
AND ANIMAL LIFE. 271 
 
 merits V. and VI. the effects were almost instan- 
 taneous. The heart therefore is not protected by 
 being subject to the whole brain, but because the 
 sensorium has no direct influence through the ?ier- 
 vous system upon the action of the heart. 
 
 CCXCI. If the heart were influenced by 
 the whole brain, in the sense understood by 
 some physiologists, we should naturally expect, 
 when the whole of this organ was removed, that the 
 action of the former would be materially affected, 
 which is not the case. If the connexion of these 
 organs be regarded as simply nervous, and of that 
 extensive description that the nerves of the heart 
 derive their power from every part of the brain,* 
 the possibility of completely destroying this re- 
 lation without injuring the contractions of the 
 heart, is completely at variance with such an 
 opinion. 
 
 CCXCII. FONTANA destroyed the brain and 
 spinal cord of 24 frogs ; the same organs in 
 the same number of frogs were left entire. The 
 48 were made to swallow a certain quantity of 
 opium, for the purpose of observing whether the 
 action of the heart would be more influenced in 
 the one set than in the other ; but there was no 
 difference in the results. MONRO endeavoured 
 to affect the limb of a frog through the sciatic 
 nerve, which was isolated, but did not succeed.f 
 * WILSON PHILIP, p. 118. 
 
 t Essays and Observations Physical and Literary, Art. XIII. 
 p. 295. Vol. III. Many experiments have been performed in 
 
THE LAWS OF ORGANIC 
 
 This distinguished anatomist also proved, that 
 opium produces its effects when all the nerves of 
 a part to which it is applied are cut out. 
 
 CCXCIII. It has been shown by different 
 physiologists, that mechanical means, such as 
 pressure, either partial or general, applied to the 
 brain, disturbs the regular motions of the heart ; 
 and this fact, instead of supporting the views of 
 WILSON PHILIP in regard to the nervous con- 
 nexion existing between these organs, will be 
 found, if examined, to strengthen the principles 
 proposed, in which I endeavour to prove, that the 
 circulation is the only medium through which these 
 derangements are communicated. The heart has 
 been shown to be independent of the brain, yet 
 capable of being influenced through it. If the 
 former organ be independent of the latter, the 
 sensorium is every moment dependent upon the heart 
 for its vitality and the exercise of its functions ; 
 therefore, whatever mechanical means are applied, 
 whether to the whole or any single part, will con- 
 sequently disorder the action of the heart in pro- 
 portion to the extent of the sanguiferous system 
 implicated. The return and distribution of the Hood 
 will be retarded or arrested ; and this circumstance 
 
 order to ascertain the action of opium and other substances 
 upon the animal economy since this able article was written ; 
 but I am much disposed to think that we have gained scarcely 
 one sure step for the last half century, at the commencement 
 of which it was published. In reference to this subject we 
 may employ the words of a German anatomist, <f that what is 
 new is not true, and what is true is not new.' 1 
 
AND ANIMAL LIFE. 273 
 
 cannot occur, without giving rise to evident effects 
 in the contractions of the heart. 
 
 CCXCIV. Pressure cannot disorder the motions 
 of the heart by deranging the nervous fluid in its 
 flow to this organ, because the action of this is 
 slightly altered by the destruction of the cerebrum 
 itself in which this supposed agent is annihilated; 
 neither can it be considered precisely in the light 
 of an irritant, because the hemispheres of the brain, 
 which may be particularly acted upon, have no 
 obvious and direct connection with the nerves 
 which are distributed to the heart ; and, more- 
 over, the application of pressure to a pulpy mass 
 does not possess the qualifications necessary to 
 disturb the remote relations of the nervous sys- 
 tem by the irritation it produces. But pressure, 
 and all mechanical means, are well calculated to 
 occasion immediate disturbance in the general 
 circulation of the system, particularly in the con- 
 tractions of the heart, from the direct and close 
 communication existing between this organ and 
 the brain. 
 
 CCXCV. MONRO,* and WILSON PHILIP, as- 
 certained by experiment, that a solution of opium 
 poured into the cavity of the abdomen produced 
 more speedy effects than the same applied to the 
 mucous membrane of the intestines, or almost 
 any other part of the body. The former ima- 
 gines this circumstance to arise from the nerves 
 
 * Id. opus, p. 145. 
 
 S 
 
274 THE LAWS OF ORGANIC 
 
 belonging to the peritoneum or intestines be- 
 ing affected ; the latter brings forward a contrary 
 opinion, supported by direct experiment, in which 
 he attempts to show, that opium applied to the 
 coats of the blood-vessels destroys their muscular 
 power, and therefore must " influence the motion 
 of the heart, by impeding, or entirely interrupt- 
 ing, that of the blood, in nearly one-third of the 
 whole animal."* 
 
 This explanation is very ingenious, but far 
 from being correct. He supposes that the heart 
 becomes immediately affected from the muscular 
 power of the capillary vessels being destroyed, 
 preventing the usual quantity of blood being trans- 
 mitted to the heart. To shew that it does not, 
 by any means, depend on this cause, I removed 
 the intestines in Experiments VII. IX. and X. 
 and applied a stimulus to the vena cava, just 
 above the pelvis, and found that the motions of 
 the heart were almost instantaneously quicken- 
 ed, and, still further, that the effect in some de- 
 gree was proportionate to the vicinity of the vein 
 acted upon to the heart. By applying the agent 
 to large vessels, we cannot suppose we either 
 paralyse or stimulate the coats, so as to affect indi- 
 rectly the circulation ; and therefore the stimulus 
 or sedative must be conveyed by the absorbents 
 or blood-vessels. 
 
 * A Treatise on Febrile Diseases, Vol. IV. p. 685. 
 
AND ANIMAL LIFE. 275 
 
 CCXCVI. The correctness of WILSON PHILIP'S 
 explanation rests on the supposition, that nearly 
 one-third of the blood of the system is prevent- 
 ed from flowing to the heart ; but if the opium 
 influenced merely the quantity of the vital fluid, 
 and did not diminish the irritability of the heart, 
 by being carried to this organ by the circulation, 
 its contractions would continue much longer, and 
 would be less sensibly retarded by the applica- 
 tion of such means. 
 
 CCXCVI I. Galvanism is one of the most pow- 
 erful stimulants we possess, and when its mode 
 of action on the animal economy is well under- 
 stood, many diseased and deranged states of the 
 system will be alleviated or removed by its ap- 
 plication. This agent has been frequently em- 
 ployed to prove that the heart can be excited 
 through the nerves distributed to its muscular 
 substance ; and the following Experiments will 
 show that this effect is as readily produced by 
 applying the positive or negative wire to the 
 vein, or almost every other part of the body, as 
 to the nerves themselves. In these Experiments 
 two troughs, each of 50 two-and-a-half inch plates, 
 were used. Adult rabbits were always employed. 
 
 EXPERIMENT I. 
 
 The negative side of the battery was connected with the 
 
 heart, and the positive with the jugular vein. The heart 
 
 was immediately affected ; its enfeebled contraction was 
 
 changed into an imperfect vermicular motion. The posi- 
 
 S 2 
 
276 THE LAWS OF OBGANIC 
 
 live wire was afterwards brought in contact with the vena 
 cava in the abdomen ; the heart was again excited, but did 
 not present the same peculiarity. 
 
 EXPERIMENT II. 
 
 The negative wire, in the preceding experiment, was in 
 contact with the heart, the positive was connected with the 
 mucous membrane of the nose ; the contractions of the 
 heart were instantly renewed. The same effect was observed 
 on the positive wire being placed in the substance of the 
 brain. 
 
 EXPERIMENT III. 
 
 Galvanism was employed as in the two preceding examples, 
 but the results were scarcely perceptible. This is proba- 
 bly to be attributed to the loss of nervous irritability, the 
 contractions of the heart having been previously arrested 
 by prussic acid applied to the brain, and to the heart it- 
 self. 
 
 EXPERIMENT IV. 
 
 In this experiment the positive wire was connected with 
 the heart, and the negative brought in contact with the 
 mucous membrane of the nose. The motions of the heart 
 were instantly renewed, characterised by the vermicular 
 contraction previously alluded to ; the negative was then 
 connected with the par vagum, and subsequently with the 
 jugular vein, at all times isolated, and the same effects 
 occurred. 
 
 EXPERIMENT V. 
 
 In this experiment the wires were placed as in the pre- 
 ceding, and the results were the same. A curious cir- 
 cumstance occurred in this experiment, which is worthy 
 
AND ANIMAL LIFE. 277 
 
 of being mentioned. While the positive wire remained 
 connected with the heart, Mr KEMP was busy in applying 
 the negative to different parts of the body. He at last 
 placed it in contact with the external surface of the sto- 
 mach, which occasioned no contractions, probably from its 
 being rather dry ; but, either accidentally or intentionally, 
 he penetrated the parietes of this organ, which produced 
 violent motions of the extremities, diaphragm, and heart. 
 He inquired if there were not a nervous coat which would 
 explain the phenomenon. Mr CHESTER answered him in 
 the affirmative, and at the same moment laid it bare ; but 
 when the wire was brought in contact with this nervous coat, 
 no contractions followed its application : they returned with 
 the same violence when the wire penetrated the parietes of 
 the stomach. I proposed that the food should be exposed, 
 which was done, and when the wire was placed in the half- 
 digested contents, the motions of the extremities, dia- 
 phragm, and heart became as evident as in the first in- 
 stance. 
 
 EXPERIMENT VI. 
 
 Having proved, by the preceding experiments, that the 
 motions of the heart and other parts of the system could 
 be excited equally through nerves, mucous membranes, 
 veins, and the food in the stomach, I suggested a further 
 modification. The heart, after having illustrated the 
 above views for about a quarter of an hour, was entirely 
 separated from the body, and isolated by means of glass ; 
 a piece of thread was then tied to a small portion of the 
 aorta connected with the organ, and was afterwards mois- 
 tened. When the positive wire was in contact with the 
 heart, and the negative with the thread, or when reversed, 
 the contractions of the heart were again manifest. These 
 
278 THE LAWS OF ORGANIC 
 
 were not characterised by an almost imperceptible motion 
 of a few muscular fibres, but were accompanied by the 
 simultaneous contractions of the different cavities. 
 
 EXPERIMENT VII. 
 
 In this experiment the positive wire was in contact with 
 the heart, and the negative alternately with the par vagum, 
 jugular rein, vena cava, mucous membrane of the nose, 
 and food in the stomach, and precisely the same results 
 took place as have been already stated. 
 
 EXPERIMENT VIII. 
 
 The heart being removed from the chest, and isolated as 
 before, a thread was tied round the remaining portion of 
 the aorta. The positive wire was connected with the heart, 
 and the negative with the thread, previously moistened. 
 The contractions in this experiment were more evident than 
 in the preceding examples. The free end of the thread was 
 afterwards placed in the centre of the food, and at the 
 same time that the negative wire was in contact with the 
 contents of the stomach, the positive still remaining in 
 connection with the heart, the contractions of this organ 
 were again as manifest as if the galvanic power had pass- 
 ed through the par vagum, or directly through the thread. 
 
 Mr CHESTER, Mr KEMP, and Mr HARDY, assisted at 
 all the experiments contained in this chapter, with the 
 exception of Experiment IX. p. 269, and Mr BROOKS, 
 Dr SAVAGE, and Captain BROWN, the Conchologist, were 
 present at several of the experiments. 
 
 From the preceding experiments and views, 
 we are authorised to draw the following conclu- 
 sions : 
 
AND ANIMAL LIFE. 279 
 
 1. That the heart is influenced by mechanical agents of 
 every description applied to the brain, in proportion to 
 the disturbance induced in the sanguiferous system. 
 
 %, That the heart is influenced by chemical agents applied 
 to the brain, according to the extent of surface, or ce- 
 rebral substance occupied by the individual agent, as 
 the absorption of the same is regulated by these con- 
 ditions. 
 
 3. That the heart is affected in degree according to the 
 
 strength and quantity of chemical means employed, 
 and the vicinity of their application to it. 
 
 4. That the heart can be influenced by galvanism equally 
 
 well through nerves, veins, and arteries, through 
 the substance of the brain, mucous membrane of the 
 nose, food in the stomach, and moistened thread ; 
 indeed the effect produced appears independent of 
 any organic inherent quality. 
 
 5. Those parts of the animal frame appear the most 
 
 powerfully excited by galvanism which seem to be 
 endowed with the greatest quantity of motory nerves, 
 viz. the extremities, the heart, diaphragm, and mus- 
 cles of the face. 
 
 6. That the heart is not protected from irregularity be- 
 
 cause it derives its power from the whole brain, but 
 because it has no nervous or direct connexion with the 
 cerebral mass of the hemispheres through which it can 
 be readily affected. 
 
 7. It would also appear probable, that the irritability or 
 
 motory property of the heart was not materially 
 affected by the destruction of the brain and spinal 
 cord, as its contractions were found to continue long 
 after their removal, if the circulation of the blood were 
 maintained by inflation. This circumstance is ex- 
 tremely favourable to the opinion expressed in the pre- 
 ceding inference. 
 
280 THE LAWS OF ORGANIC 
 
 CHAP. XIII. 
 
 On Palpitation. 
 
 SECT. I. The General Causes which produce this 
 Affection. 
 
 CCXCVIII. WE have scarcely a slight cough 
 or pain, if the pulse be quick or small no uneasi- 
 ness of stomach, shooting or fixed pain of head 
 no heaviness or lightness palpitation of heart, or 
 irregular pulsation in any part of the system, but 
 now comes within the definition of a nervous 
 affection and the treatment of a nervous princi- 
 ple. The idea of a nervous power has had great 
 influence in the treatment of diseases of the heart. 
 When indications of practice were not well mark- 
 ed, or did not appear very urgent, we have too 
 frequently disregarded them as mere nervous de- 
 rangements, till, from neglect, they have demand- 
 ed prompt and active measures, at a time proba- 
 bly when our means allow us to palliate only. 
 
 CCXCIX. Palpitation occurring in the nervous 
 temperament is characterised by its quickness, 
 and the gentle impulse which it gives ; the chest 
 is not elevated by its action ; the pulse is frequent 
 and small, and the animal heat scarcely at all 
 changed. 
 
AND ANIMAL LIFE. 281 
 
 CCC. In individuals of a purely nervous con- 
 stitution, the parietes of the heart, its valves 
 or vessels, are seldom much disorganized ; but pa- 
 tients who have been long troubled with such 
 complaints are remarked to die frequently of 
 Phthisis ; and in those cases in which we cannot 
 discover the efficient cause of death, we observe, 
 on dissection, the traces of chronic disease of the 
 thorax and abdomen, such as congested or tu- 
 berculous lungs, indurated or enlarged liver, vas- 
 cular or thickened appearance of the stomach, 
 or adhesions in some parts of these cavities. We 
 shall now investigate the causes which determine 
 palpitation, and endeavour to explain the various 
 kinds of disorganizations, either co-existent with, 
 or subsequent to such an affection. 
 
 CCCI. An individual, from the preponder- 
 ance of the nervous temperament,* is prone to 
 receive slight external impressions ; shadows 
 seem tangible ; ordinary sounds are deemed ano- 
 malous or strange, and the different senses ap- 
 pear to acquire additional acuteness. The con- 
 tinued operation of these causes predisposes the 
 system to organic changes, or functional derange- 
 ments. The frame is emaciated, the cheek loses 
 the glow of health, the mind its usual buoyancy, 
 and the appetite becomes fastidious. The men- 
 tal anxiety which he suffers, the inactivity of 
 
 * I continue the use of this term, as it conveys to the mind 
 of the reader the character of the constitution particularly 
 predisposed to palpitation. 
 
282 THE LAWS OF ORGANIC 
 
 life which he leads, the neglect of proper food, 
 and stimuli, such as society, fresh air, and the in- 
 fluence of pleasurable objects, have one general 
 tendency, to change the equality of the circulation. 
 The influence of these causes, from the first, has 
 been to determine the blood upon the internal 
 organs, as proved by the paleness or otherwise 
 unnatural complexion of the countenance and 
 surface of the body, the great sensibility to cold, 
 the want of appetite, and the irregularity of 
 other organic functions. I have previously stated 
 that this condition of the sanguiferous system 
 invariably tends to diminish the stimulating pro- 
 perties of the blood; and, from the combination 
 of these causes, we shall be enabled to give rea- 
 sons for the occasional occurrence of palpitation. 
 
 CCCII. The lungs and the heart are inti- 
 mately connected by the nature and proximity 
 of their functions. If the heart, from malconfor- 
 mation, be not capable of propelling the blood 
 which the lungs transmit, syncope or death is the 
 consequence ; or if the lungs, on the other hand, 
 send blood deficient in its ordinary qualities, the 
 pulsations of this organ become weak, cease, or 
 exhibit convulsive action ; or if it be unusually 
 oxygenated, its contractions are forcible and fre- 
 quent. 
 
 CCCIIT. In the nervous constitution, when 
 the heart is troubled by occasional palpitation, 
 the lungs, in common with the rest of the inter- 
 
AND ANIMAL LIFE. 283 
 
 nal viscera, possess more of the sanguineous fluid 
 than is consistent with the proper performance 
 of their office; and, therefore, the connexion 
 between these important organs is rendered highly 
 susceptible to slight alterations occurring in the 
 general circulation. Mental emotions, fatigue 
 of mind or body, or internal functional disor- 
 ders, by disturbing still more the quantity or 
 quality of blood transmitted from the lungs to 
 the heart, derange the contractions of the latter 
 organ. If the quantity of blood which is sent to 
 the heart be greater than usual, its powers are 
 oppressed, or, from the urgent circumstances in 
 which it is placed, it is unable to circulate the 
 blood it receives with ordinary regularity, and its 
 convulsive motion or irregular action is the con- 
 sequence of this inability. Palpitation, in such 
 instances, arises therefore from the general cause, 
 an overcharged state of the lungs. 
 
 CCC1V. In the nervous temperament the 
 pulse is frequent and small. The heart contracts 
 in frequency and force, cceteris paribus, propor- 
 tionately to thedegree of stimulus which the blood 
 possesses. In this state of the system the blood 
 is deficient in its usual stimulating qualities from 
 the causes mentioned in CCCI. Consequently, 
 the heart neither dilates nor contracts so fully as 
 in the state of health : but the necessity of propel- 
 ling the blood is great ; it is, therefore, compelled 
 
284 THE LAWS OF ORGANIC 
 
 to accomplish, in frequency and feebleness, what it 
 sometimes performs in slowness and energy. 
 
 The causes which have been mentioned as hav- 
 ing the general tendency to determine the blood 
 upon the internal organs, and which alteration is 
 also invariably accompanied by a deteriorated 
 condition of the blood, affect, in the first place, 
 the different viscera with derangements, the con- 
 tinuation or severity of which ultimately gives 
 rise to the various disorganizations observed in 
 the lungs or abdominal organs. 
 
 CCCV. Having briefly investigated the man- 
 ner in which the internal organs are disordered 
 by mental emotions, fatigue of mind or body, or 
 other depressing causes, we are now prepared to 
 understand in what way these derangements are 
 removed by exercise, fresh air, lively society, and 
 other kinds of amusements. Muscular exertion, 
 and the cheerful feelings of the mind, promote 
 the better oxygenation and circulation of the 
 blood. The former equalizes the distribution of 
 the vital fluid, and this change diminishes the 
 proportion existing in the lungs, and the benefi- 
 cial results which follow are in accordance with 
 the principles of the first chapter: the latter 
 improves the inspirator^ or irregular character 
 of the respiration. 
 
 CCCVI. In infancy and childhood, palpita- 
 tion seldom occurs. At this age, every organic 
 function is active ; respiration is more frequent ; 
 
AND ANIMAL LIFE. 285 
 
 the pulsations of the heart are more numerous 
 and regular than at any subsequent period. From 
 the force of the circulation, the energy of each 
 organ, and the unclouded serenity of the mind, 
 there are few causes capable of producing an 
 overcharged state of the lungs. 
 
 CCCVII. Palpitation of the heart occurs 
 very frequently in the constitution of the female 
 at two very different periods of life. On the de- 
 velopment of the uterine functions, the circula- 
 tion of the blood undergoes great changes ; new 
 demands are made, and the regular course of the 
 vital fluid is directed to other organs. But these 
 important alterations are not immediately esta- 
 blished, and, until they are, disorders in the cir- 
 culation, disturbing the motion of the heart, are 
 extremely liable to occur. When these organs 
 are fully formed, the delicacy of their functions 
 is subject to the influence of many circumstances, 
 all of which act powerfully on the distribution of 
 the blood. At the latter period of life, the de- 
 mands of these parts of the system are diminish- 
 ed. The blood, which has for a series of years 
 been determined here to supply the activity of 
 functions unessential to life, is now no longer 
 required : It is therefore the intention of Nature 
 to diffuse the quantity appropriated to these func- 
 tions equally throughout the system ; but the at- 
 tainment of this object is occasionally opposed, or 
 
286 THE LAWS OF ORGANIC 
 
 rendered imperfect by a variety of causes calcu- 
 lated to derange the sanguiferous system. 
 
 CCCVIII. The application of cold has the ten- 
 dency to determine the blood upon the internal 
 organs; and if palpitation be the consequence 
 of its influence, this arises from an overcharged 
 state of the lungs. 
 
 SECT. II. Organic Causes which produce Palpitation. 
 
 CCCIX. WHEN we examine the organization 
 of the heart the delicate adaptations of its 
 valves the constitution of its cavities the con- 
 tinued action of its parietes and the variety of 
 vessels with which it is connected, we are in 
 some measure prepared to expect that a multipli- 
 city of causes will tend to disorder its function 
 by the disorganization occasioned in the com- 
 ponent parts of its structure. 
 
 CCCX. The organic diseases of the heart, 
 and those of other organs that produce palpita- 
 tion or irregular action, are divided into three 
 general classes, 
 
 1. The first class includes the organic diseases 
 of the heart itself. These, although differ- 
 ing in nature, situation, and extent, are clas- 
 sified, from possessing one common tendency, 
 to obstruct the natural current of the blood 
 through the cavities of the heart. 
 
AND ANIMAL LIFE. 387 
 
 2. The second class includes thoracic and abdo- 
 
 minal affections, diseases, and injuries of the 
 spine, and medulla oblongata, which are 
 also classified, from possessing one common 
 influence on the organs of respiration. 
 
 3. Tumours and many anomalous diseases, which 
 
 seem to act directly upon the larger vessels 
 of circulation, constitute the third class. 
 
 CCCXI. The first class is extremely extensive. 
 For the purpose of facilitating description, and of 
 shewing more clearly than I otherwise could the 
 consistency of the classification, it is subdivided 
 as follows : 
 
 a, a small heart. 
 
 b, one or more of its cavities enlarged or dimi- 
 nished in capacity. 
 
 c, diseases of the valves proper to the heart and 
 the great vessels with which it is directly con- 
 nected. 
 
 c?, inflammation. 
 
 e, adhesion of the pericardium. 
 Jl imperfect organization of the heart. 
 
 CCCXII. The heart may be perfectly well 
 formed in relation to itself; its cavities, valves, 
 and parietes, may be proportionate to each other ; 
 yet, as a whole, its relation to the system may 
 be inaccurate, and therefore may predispose to 
 occasional irregularity of action. 
 
288 THE LAWS OF ORGANIC 
 
 CCCXIIL During the state of repose, when 
 the circulation is equable or little invigorated, 
 such a heart may perform its office ; but if muscu- 
 lar exertion be employed, or powerful internal 
 stimuli be taken, or if the mind be excited by 
 violent passion, more blood is transmitted in a 
 given time than it is capable of receiving or pro- 
 pelling with its accustomed regularity. This 
 peculiar conformation may sometimes be the 
 cause of palpitation on occasions apparently un- 
 important. It will make the heart extremely 
 liable to suffer from an overcharged state of the 
 lungs. 
 
 CCCXIV. The heart, as a whole, may, in 
 its relations to the system, be exact, yet its parts 
 may want harmony among themselves. If we 
 were sufficiently advanced in knowledge to esti- 
 mate slight deviations of this kind, it is not im- 
 probable that many symptoms, otherwise inex- 
 plicable, would be found to originate in such a 
 conformation. When a ventricle or auricle is evi- 
 dently enlarged or diminished, we are almost sure 
 to find this accompanied by con sequences that can- 
 not be referred to any other cause than an increased 
 or diminished capacity ; and it is not improbable 
 that the predisposition of some individuals to oc- 
 casional palpitation is sometimes to be attributed 
 to this cause. When a cavity is lessened, which 
 sometimes occurs, its parietes,for the most part, are 
 considerably thickened, and this condition consti- 
 
AND ANIMAL LIFE. 289 
 
 tutes one form of hypertrophy. If one cavity 
 be less, from disease, than it ought to be, it is 
 clear that its diminished capacity cannot receive 
 the same quantity of blood. If the seat of this mal- 
 conformation be the right auricle, every motion of 
 the bddy that facilitates circulation will be apt to 
 derange or destroy the function of the heart ; or 
 suppose the right ventricle to be dilated) the con- 
 traction of the auricle will send its usual quanti- 
 ty of blood, but a portion of this will, of necessi- 
 ty, regurgitate ; and, if the latter cavity be much 
 excited, it will send more than it is accustomed 
 to transmit, and, in this way, it will hasten the 
 effects called palpitation, or irregular action of 
 the heart. This phenomenon occurs because the 
 augmented cavity is frequently accompanied by 
 debility. The thin parietes in passive aneurism 
 do not present the same quick sound to the ear, 
 the same strong impulse to the hand, nor the same 
 frequent and bounding pulse that are observed in 
 active aneurism. Palpitation in both conditions is 
 produced by the same exciting causes. Whenever 
 a quantity of blood, greater than what is natural, is 
 transmitted to the dilated ventricle or auricle, its 
 attenuated parietes are inadequate to the task of 
 propelling it, the consequence of which is, that 
 the fluid accumulates, and excites the heart to 
 convulsive or irregular action. SEXAC and others 
 have imagined, that the cavity being larger, it 
 must necessarily be more stimulated, as it possess- 
 
 T 
 
290 THE LAWS OF ORGANIC 
 
 es more blood. This reasoning is evidently fal- 
 lacious. If we suppose the enlarged cavity to 
 receive an ounce of blood, instead of half this 
 quantity in its natural condition, each superficial 
 particle of this fluid, as in ordinary cases, will be 
 applied to a given point of the internal surface, 
 and will act on this point as if the cavity were 
 only half the size. The contractions of the heart 
 may be regarded as made up of an infinity of 
 smaller motions, arising from the innumerable 
 particles of blood : therefore, one cavity twice 
 the size of another, supposing equality in every 
 other respect to exist, cannot possess a greater 
 proportional stimulus, or exercise a more ener- 
 getic action. If it contained a greater propor- 
 tional quantity of blood, and were on that ac- 
 count more excited, the muscular fibres would 
 exhibit greater strength in their contractions; 
 but these are slow, and feeble even in the state of 
 palpitation, compared to those of the naturally 
 organized heart when inordinately stimulated. 
 
 CCCXV. Diseased valves may be regarded as 
 the cause of almost every change of structure 
 that affects the heart ; their extreme delicacy dis- 
 poses them to suffer from every irregularity of 
 action in the sanguiferous system ; and when dis- 
 ordered, their importance makes them readily 
 produce derangement of function, or structural 
 disorganization in other parts near and remote. 
 If they become cartilaginous or ossified, or if 
 
AND ANIMAL LIFE. 291 
 
 they diminish or increase the communications 
 between two cavities, the heart will be predis- 
 posed to palpitation. 
 
 CCCXVI. Vegetations, and all kinds of accre- 
 tions, may probably be looked upon as simply 
 lessening the cavity, and placing this in circum- 
 stances somewhat similar to the one whose ca- 
 pacity is diminished by a thickening of its mus- 
 cular pariet.es. 
 
 CCCXVII. Inflammation of the heart is for- 
 tunately a rare disease. If well marked in its 
 symptoms, it often terminates in death, or occa- 
 sions chronic affections of the lungs or great 
 vessels. The peculiar feature in this disease is, 
 that the irritability of the heart is increased, and 
 is violently acted upon by the presence of blood 
 possessing, for a short time, its usual qualities. 
 The derangement of the circulation, and the 
 sufferings of the patient, promote the respiratory 
 function ; the blood becomes better arterialmed, 
 and this irritates still more the sensibility of the 
 inflamed organ. 
 
 CCCXVIII. Ossification of the coronary ar- 
 teries hr,s not been included in the subdivision 
 of the first class, because I am rather inclined to 
 believe that its importance Iras been exaggerated. 
 Angina Pectoris, which it is said to occasion, has 
 too frequently been found to occur, in all its 
 severity, without the least trace of ossification, 
 to allow us to suppose that this condition of the 
 
 T 2 
 
292 THE LAWS OP ORGANIC 
 
 vessels is necessary for its production ; and it has 
 also been observed, that ossification of the corona- 
 ry arteries has been detected in individuals who 
 were exempt from every symptom of the disease. 
 
 If ossification has any effect upon the heart, 
 it must diminish the freedom of its action, 
 either by lessening its nourishment or by de- 
 stroying the contractility of its muscular fibres. 
 Whether the muscular fibres of the heart or its- 
 vessels be disorganized, the valves diseased, 
 or the openings between the cavities enlarged or 
 diminished, or whether the great vessels con- 
 nected with the heart be affected, or the proper 
 proportions between the cavities be wanting, a 
 paroxysm will be excited whenever a greater 
 quantity of blood is transmitted in a given time 
 to the organ than its condition is able to receive or 
 propel. 
 
 CCCXIX, BURNS, in his Treatise on the Dis- 
 eases of the Heart, quotes the opinion of BELL, 
 as apparently explaining the manner in which a 
 child overcomes or shortens a paroxysm of the 
 Casrulean disease, which presents the same ge- 
 neral symptoms as Angina Pectoris, except in 
 certain external signs, which depend on a differ- 
 ence of the organic cause that induces this state 
 of Asphyxia. He says, " the patient lessens the 
 capacity of the chest, if he be very young, by 
 turning on his belly, or if he be older he presses 
 his breast firmly against a table or any solid ob- 
 
AND ANIMAL LIFE. 293 
 
 ject," that lie may expel "portion after portion 
 of the contaminated air, as will in some measure 
 restore the balance of arterial and venous blood." 
 If this opinion be examined, it will be found ku 
 correct. It is not the bad air which the chest 
 contains, nor the good which it wants, that pro^ 
 longs or would relieve the paroxysm. If the pa- 
 tient could receive oxygenated air, and if this 
 stimulated as it does in a natural inspiration, it 
 is not improbable that the life of the individual 
 would be destroyed. The introduction of fresh 
 air would accelerate the circulation, and send a 
 still greater quantity of blood to the heart, which 
 ceased, and ceases to act, because it had, and has, 
 more than it can circulate. During the Asphyxia- 
 ted stage of the paroxysm, the heart, in the great- 
 er number of instances, is operating slowly with-, 
 out the dangerous assistance of the lungs ; but as 
 this is only to a small extent, it requires some 
 time before it can relieve itself of its accumulat- 
 ed burden : when it has accomplished this object, 
 inspiration succeeds, and the stimulus of the air 
 is then beneficial, as it tends to establish the har- 
 mony which must subsist between the respiratory 
 and the circulatory systems. 
 
 CCCXX. The efforts which the individual 
 makes are instituted neither to admit pure nor 
 send out impure air. The patient, whether sen- 
 sible, or only obscurely so, during the paroxysm, 
 invariably acts from sensations. The congestion 
 
294 THE LAWS OF ORGANIC 
 
 of the lungs is accompanied by painful states of 
 the mind, and, without being directed by any 
 ideas of his own, he follows the impulse of his 
 feelings, and these will give rise to his pressing 
 the chest, or rolling upon his belly, as it is in 
 these regions that the pains have originated, and 
 in these in which they are continued. 
 
 CCCXXL I am not aware in what manner 
 adhesion of the pericardium to the heart produces 
 palpitation ; that it does so, is not improbable. Ad- 
 hesion is so frequently connected with this organ, 
 without its presence being indicated by such an 
 affection, and when this irregular action has been 
 found co-existent with such a disorganization, 
 there has been likewise so much partial or general 
 disease, that the difficulties deter me from forming 
 even a conjecture on the subject. 
 
 CCCXXII. Imperfect organization of the heart 
 is well illustrated by theCasrulean disease. BURNS, 
 in speaking of this affection, observes, that part 
 of the blood passes through the foramen ovale into 
 the left auricle ; and when the ductus arteriosus 
 is also pervious, another portion is transmitted 
 from the pulmonary artery to the aorta ; the 
 third and remaining quantity circulates through 
 the lungs in the usual way. The blood in the 
 two former divisions undergoes no change, but 
 mingles with the arterial in the situations in 
 which it terminates. This account is perfectly 
 correct. He then remarks, " Now, from this 
 
AND ANIMAL LIFE. 295 
 
 short statement, it must be obvious, that, sooner 
 or later, an accumulation of blood, highly venous, 
 must take place in the arterial system; and 
 whenever this proceeds a certain length, we are 
 prepared to understand why the body feels weak ; 
 why the pulse flutters and the heart vibrates ; 
 why the vital functions are nearly arrested ; and 
 why the person expresses the greatest anxiety 
 and oppression in the chest, referrible in part to 
 the presence of venous blood in the left side of 
 the heart, but occasioned equally by the consent 
 which obtains between this organ and the lungs. 
 Such is a general explanation of the cause of the 
 occurrence of a paroxysm."* " Let me next 
 observe," he says, " that whatever renders the 
 circulation irregular accelerates the accession of 
 a fit, as then, from the increased frequency of 
 the vascular contractions, blood comes to be more 
 rapidly transmitted through the heart, and thus 
 venous blood is poured more frequently into the 
 arterial system ; inducing thus, in a shorter time, 
 the train of symptoms which would inevitably 
 have followed, though at a somewhat more re- 
 mote period." 
 
 CCCXXIII. It is difficult to conceive how 
 one so acute and original as BURNS should have 
 been so illogical in his reasoning on the preced- 
 ing phenomena. In the first place, he observes, 
 
 * Observations, or View of the most frequent and impoir 
 ,tant Diseases of the Heart; by ALLAN BURNS. 
 
296 THE LAWS OF ORGANIC 
 
 " It must be obvious, that sooner or later an ac- 
 cumulation of blood, highly venous, must take 
 place in the arterial system." This is an asser- 
 tion without the least support. By accumula- 
 tion, we understand a heaping up, or adding to, 
 a condition which cannot occur in the arterial 
 system, from the intermixture of the venous 
 blood ; because it is impossible to destroy, or, in 
 any measure, change the relative proportions of 
 these fluids. The paroxysm he mentions ar- 
 rests, in the same ratio, the arterial and venous 
 blood, because respiration, on which they both 
 depend, has ceased to act. If the accumulation be 
 granted, how can this be modified, since no al- 
 terations can possibly influence the arterial or 
 venous system individually ? The incorrectness 
 of this opinion becomes more evident as we pro- 
 ceed. Let us suppose an individual with the 
 Casrulean disease to be perfectly easy ; his respi- 
 rations about twenty per minute, and his pulse 
 about seventy ; and let us still further suppose, 
 that the foramen ovale and the ductus arteriosus 
 are represented by the letters A and B, and the 
 regular passage between the right ventricle and 
 the lungs by C, we may state that the quantity 
 of blood which A and B transmit under these cir- 
 cumstances to be estimated at eight ounces in 
 the minute, and the quantity sent by C to be 
 oxygenated in the lungs at twelve ounces in the 
 same time. If, by exercise, or other causes, the 
 
AND ANIMAL LIFE. 297 
 
 respirations become thirty, and the pulse one 
 hundred per minute, A and B may send twelve 
 ounces in the place of eight ; but C must also cir- 
 culate sixteen instead of twelve in the same pe- 
 riod. 
 
 It must appear manifest, that no accumulation 
 can ever happen in the way in which it has been 
 stated; and, moreover, it is equally clear, that 
 quickened circulation cannot alter the proportions 
 of arterial and venous blood. The paroxysm is 
 occasioned by the determination of blood to the 
 lungs, either from exercise or mental emotions. 
 When such a conformation exists, the delicacy 
 of the adjusted parts is liable, almost every mo- 
 ment, to be disturbed ; and when a paroxysm 
 does occur, the sanguiferous system recovers its 
 ordinary power, as stated in CCCXIX. 
 
 CCCXXIV. We now enter upon the con- 
 sideration of the abdominal and thoracic affec- 
 tions, constituting the second class ; and shall 
 briefly show the influence they exert on the organs 
 of respiration. Among the diseases of the abdo- 
 men which tend to disorder respiration and its 
 dependent system circulation, are included tym- 
 panites, dropsy, enlarged liver, and tumours. 
 Its functional alterations are pregnancy and dis- 
 tention of the stomach. They all possess one com- 
 mon physical condition, viz. that they diminish the 
 capacity of the thorax. The extent of this change, 
 and the variety and character of its effects, will 
 
298 THE LAWS OF ORGANIC 
 
 be materially modified by the natural conforma- 
 tion of the system, or any of its parts ; by the 
 complexity of the disease, the number of .organs 
 affected; and, lastly, by the re-action of many 
 causes which we cannot correctly appreciate. 
 
 CCCXXV. It is not by any means easy to 
 point out, in a precise manner, the operation of 
 these different causes in inducing palpitation. 
 We observe, in the greater number of instances, 
 that the breathing is short and hurried by gentle 
 exercise, or from slight mental emotion, when the 
 system is subjected to any of these physical con- 
 ditions ; and we are compelled to acknowledge 
 that the circulation of the blood is dependent on 
 respiration, and is also influenced by every change 
 or disorder occurring in the latter. Therefore, it 
 can scarcely be called in question, that in pro- 
 portion as we render the performance of a func- 
 tion delicate, we augment the liability to derange- 
 ments in organs whose every action is regulated 
 by the character of that function. It is on this 
 account that palpitation of the heart and syncope 
 are occasional symptoms in pregnancy, and in 
 other cases in which the con tents of the abdomen 
 diminish the free descent of the diaphragm. 
 
 CCCXXVI. We have at times palpitation of 
 the heart, or a predisposition to it, in many inter- 
 nal diseases, the operation of which cannot be re- 
 ferred to any physical state, acting either on the 
 diaphragm or directly on any organ connected 
 
AND ANIMAL LIFE. 299 
 
 with respiration, but must be regarded as affect- 
 ing the heart by the disorders which have been 
 gradually induced in the distribution of the vital 
 fluid, by the depressing mental anxiety insepa- 
 rable from disease, and also by the congestion of 
 blood, which always, more or less, accompanies 
 internal chronic affections of a severe kind. 
 
 CCCXXVII. The third class, in which we 
 have tumours, and many anomalous diseases that 
 seem to act directly upon the larger vessels of circu- 
 lation, will not require a minute consideration. 
 It is so obvious, if any part of the circulatory 
 system, indispensable for life, be disordered in its 
 function by tumours diminishing the capacity of 
 important vessels, that the contractions of the 
 heart will be irregular, or predisposed to this con- 
 dition, as these depend on the quantity, quality, 
 and motion of the fluid transmitted, that I shall 
 not attempt to enforce the argument by a super- 
 fluous examination of the subject. 
 
300 THE LAWS OF ORGANIC 
 
 CHAPTER XIV. 
 
 Syncope. 
 
 SECT. I. The manner in which the Sanguiferous and 
 Nervous Systems are acted upon by those causes which 
 produce Syncope. 
 
 CCCXXVIII. THERE are few subjects con- 
 nected with the'science of medicine so truly dif- 
 ficult as the one we propose to investigate. The 
 variety of causes which give rise to the paroxysm 
 of Syncope, the peculiar and invariable phenome- 
 na which characterize its origin, progress, and 
 termination, have tended materially to make our 
 knowledge of its proximate cause indefinite or 
 incorrect. The affection frequently occurs in 
 health, or at least at times when we have no evi- 
 dence of disease. It is a symptom which is 
 found conjoined with the slightest and most se- 
 vere indisposition ; it occasionally follows the ex- 
 hibition of medicines, or the employment of re- 
 medial measures ; and its precursory stages, or 
 symptoms, are sometimes induced, being re- 
 garded as among the most powerful means we 
 possess in counteracting inflammation. 
 
 CCCXXIX. The confusion which pervades 
 the writings and opinions of men on the subject 
 
AND ANIMAL LIFE. * 301 
 
 of Syncope, is chiefly referrible to two causes : 
 Our ignorance of the independent actions of the ner 
 vous and sanguiferous systems, and of the reciprocal 
 and necessary influence which unites the one to the 
 other. When passions or external objects have 
 occasioned Syncope, it has generally been con- 
 sidered that the motions of the heart have been 
 stopped or impeded by the direct influence of the 
 brain upon the moving powers of the blood : 
 when such consequences followed depletion or 
 the removal of an hydropic fluid, inequality in 
 the circulation was regarded as the cause. If we 
 had taken into consideration, that the heart is 
 proved to be independent of the direct agency of 
 the brain ; and, still further, if we had reflected 
 that the symptoms are invariably the same, whe- 
 ther they be referred to sensation or mechanical 
 alterations, we should probably have exercised 
 our faculties to discover the intermediate link 
 which apparently connects the mental antecedent 
 to the corporeal sequence in the production of 
 Syncope. 
 
 CCCXXX. There is not any other derange- 
 ment of the body that shows, equally with this 
 affection, the reciprocal influence of the two great 
 systems of the constitution, viz. the nervous and 
 sanguiferous ; and, without having recourse to 
 the flow or suppression of a nervous fluid, and 
 without bringing forward any gratuitous assump- 
 tions, it is not difficult to demonstrate the sim- 
 
302 THE LAWS OF ORGANIC 
 
 plicity of the phenomena with respect to cause 
 and effect, and also the consistency of the gene- 
 ral views which have been proposed to explain 
 many other derangements or diseased states of 
 the animal economy. 
 
 CCCXXXI. Dr CULLEN divides the remote 
 causes of Syncope into two general heads. " The 
 one is of those causes exciting and acting in the 
 brain, or in parts of the body remote from the 
 heart, but acting upon it by the intervention of 
 the brain. The other general head of the remote 
 causes of Syncope, is of those existing in the heart 
 itself, or in parts very immediately connected 
 with it, and thereby acting directly upon it in 
 producing this disease."* The division would be 
 correct, if the facts on which it is supposed to be 
 founded were not, in part, ascertained to be falla- 
 cious. He says, " I must assume a proposition, 
 which I suppose to be fully established in physi- 
 ology. It is this : that though the muscular 
 fibres of the heart be endowed with a certain de- 
 gree of inherent power, they are still, for such 
 action is as necessary for the motion of the blood, 
 very constantly dependent upon a nervous power 
 sent into them from the brain ."f 
 
 CCCXXXII. Since the time of CULLEN, the 
 experiments of LEGALLOIS, WILSON PHILIP, and 
 others, have satisfactorily proved, that the action 
 
 * CULLEN'S First Lines, MCLXXIV. 
 f Ibid. MCLXXV. 
 
AND ANIMAL LIFE. 303 
 
 of the heart remains when the brain and spinal 
 cord are destroyed. If this be acknowledged, the 
 opinion, that the transmission of the nervous power 
 into the muscular fibres of the heart is necessary 
 to excite or sustain its motion, cannot be receiv- 
 ed in the present state of physiology ; and there- 
 fore the explanations which he gives of the great- 
 er part of the phenomena of Syncope, are theore- 
 tical speculations. 
 
 CCCXXXIII. In the present chapter, the re- 
 mote causes of Syncope are divided into two 
 general classes. The first contains those causes 
 which act upon the external senses and the mind : 
 The second, those 'which act upon the functions of 
 respiration and circulation. 
 
 The first class is again subdivided into affec- 
 tions of the senses, such as past impressions, and 
 the pleasurable or painful states of the body. 
 
 The second class may be subdivided into those 
 causes which act directly or indirectly upon the 
 heart and the respiratory function. 
 
 CCCXXXIV. In investigating the action of 
 the individual causes included under each subdi- 
 vision, we shall find that everyone of these tends to 
 produce the same proximate cause an overcharged 
 state of the heart. This condition of the heart 
 should not be regarded as an effect of its own de- 
 bility, as generally believed, but is to be referred 
 to the greater demand made upon its powers by 
 
304 THE LAWS OF ORGANIC 
 
 every one of the above causes which occasion 
 Syncope. It is observed by a physiologist of 
 considerable talent, that " whatever increases or 
 lessens the vigour of one part must increase or 
 lessen the activity of the whole ; though the tem- 
 perature of the heart itself be no way affected, its 
 irritability is instantly diminished."* 
 
 CCCXXXV. The irritability of the heart can- 
 not immediately be influenced by the increased 
 or diminished vigour or activity of one part of 
 the system ; its action may be excited or de- 
 pressed, but this will arise from the changes 
 of its natural stimulus, the blood. If this be 
 highly stimulating, its motions will be accelerated; 
 if deprived of its usual invigorating qualities, its 
 frequent and small pulsations will indicate, that 
 such is the state of the circulating fluid, and not 
 that the irr it ability of the organ itself is so far 
 lessened as to be the cause of this difference. 
 
 CCCXXXVI. It is imagined, when the heart 
 ceases to contract, that it continues quiescent 
 until it has recovered its accustomed energy to 
 enable it to propel its contents. This idea is bor- 
 rowed from observations connected with other 
 phenomena of the system. Repose to a moderate 
 extent refreshes and strengthens our mental and 
 physical powers ; and from these facts we con- 
 clude, that repose will also be attended by simi- 
 lar consequences to the heart. 
 
 * Dr KELLIE, Edinburgh Medical Journal, Vol. 1. p. 508. 
 
AND ANIMAL LIFE. 305 
 
 CCCXXXVII. The muscles of the arm be- 
 come weak if long exerted, or if put into an un- 
 natural position ; but it is not the province of 
 these muscles to dilate and contract upon their 
 contents, in order to propel the blood regularly 
 to other organs ; alternate rest and activity are 
 necessary for their office. The heart is the cen- 
 tre of circulation, and the dependence of every 
 function on its unceasing action would seem to 
 imply, that activity alone is the condition in which 
 it can be invigorated ; and it is also found from 
 experience, that almost every cause, whether con- 
 tinued or occasional, which augments its impulse 
 increases its muscular development. 
 
 CCCXXXVII I. The heart, in a paroxysm of 
 syncope, is sometimes instantaneously arrested in 
 its motion. When this is the case, we cannot con- 
 sistently say that it is weakened, because it has 
 not been over excited, nor have we a right to sup- 
 pose that it is recruiting its nervous energy dur- 
 ing the state of quiescence. 
 
 CCCXXXIX. The general symptoms which 
 precede and characterize syncope are in the greater 
 number of instances the same, but the extent 
 and variety of these are occasionally much modi- 
 fied by the severity and suddenness of the fit. If 
 the symptoms are gradual in their progress, we 
 have nausea, vertigo, pain in the epigastric re- 
 gion, sensation of cold, tremors of the extremi- 
 ties, paleness of the countenance, lividness and 
 
 u 
 
306 THE LAWS OF ORGANIC 
 
 trembling. of the lips, and cessation or palpitation 
 of the heart. At times the attack is so instan- 
 taneous, that the individual presents few of these 
 precursory signs. 
 
 CCCXL. The subject of nausea has been stu- 
 died by almost every physiologist ; but we possess 
 at present no theory concerning it which is 
 deemed satisfactory. The derangement in the 
 circulation of blood in the head has generally 
 been received as constituting the proximate cause. 
 The reasonings which I shall employ, and the 
 facts which I shall adduce in support of them, 
 conjoined with the operation of remedial mea- 
 sures which are found to remove or alleviate the 
 feeling, will probably throw some light upon the 
 subject. 
 
 CCCXLI. Nausea, in whatever way it is pro- 
 duced, whether by the recollection of something 
 painful or some immediate affection of the senses, 
 or whether from the undulating motion of a 
 vessel, or the removal of an hydropic fluid, has 
 the same proximate cause an overcharged state 
 of the lungs. 
 
 CCCXLII. In every instance, nausea arises 
 either from a sensation communicated by the 
 brain to the respiratory functions, or from a 
 sensation occasioned by a peculiar state or change 
 of the general system, and which is immediately 
 transmitted to the cerebrum, and afterwards re- 
 
AND ANIMAL LIFE, 307 
 
 acts upon the function of respiration, or from the 
 regular course of the circulation being disturbed. 
 The established succession of inspiration and ex- 
 piration is disordered when the mind is directly 
 or indirectly concerned in the production of 
 syncope, and it will be seen by subsequent illus- 
 trations, that a quantity of blood greater than 
 what is natural is drawn to the chest by the 
 sensations which accompany nausea. 
 
 CCCXLIII. After having reflected for some 
 time on the principles which have given rise to 
 the present work, it was gratifying to discover, 
 that the late distinguished philosopher, Dr WOL- 
 LASTON, had also remarked a material change in 
 the order of his respirations during the feeling of 
 sea-sickness. Although our ideas concerning the 
 operation of this change by no means coincide, 
 yet it is corroborative to bring forward the views 
 of so able an observer in support of the tendency 
 which the respiratory functions have to promote the 
 sensations of nausea. The opinions of this phi- 
 losopher being, on all occasions, valuable, I shall 
 transcribe them. " I had the good fortune to 
 observe a peculiarity in my mode of respiration, 
 evidently connected with the motion of the ves- 
 sel, but of which, in my then enfeebled state, I 
 was unable to investigate either the cause or 
 consequence. In waking from a state of dis- 
 turbed sleep, I found that my respirations were 
 not taken with the accustomed uniformity, but 
 u 2 
 
308 THE LAWS OF ORGANIC 
 
 were interrupted by irregular pauses, with an 
 appearance of watching for some favourable op- 
 portunity for making the succeeding effort ; and 
 it seemed as if the action of inspiration were in 
 some manner to be guided by the tendency of 
 the vessel to pitch, with an uneasy motion. 
 
 " The sickness occasioned by swinging is evi- 
 dently from the same cause as sea-sickness. 
 
 " It is during the subsidence (of the vessel) 
 that the blood has a tendency to press with un- 
 usual force upon the brain."* 
 
 CCCXL1V. Dr WOLL ASTON tried to induce 
 the same sensation by swinging ; and when this 
 was present, he endeavoured to remove it by 
 making deep inspirations. He says, " Although 
 the advantage was manifest, I must confess it did 
 not fully equal the expectations I had formed 
 from my experience at sea." The result of this 
 experiment is in accordance with the principles 
 proposed. It is the more frequent or irregular 
 inspirations that are the cause of the various symp- 
 toms. 
 
 CCCXLV. There is a great difference between 
 an involuntary and a voluntary inspiration. In the 
 former the whole system is relaxed, or predis- 
 posed to increase the full effect ; in the latter, the 
 very attention or desire of the mind to enforce, 
 counteracts, in part, the consequences we antici- 
 pate. 
 
 * Lend, Phil. Trans. 1810. 
 
AND ANIMAL LIFE. 309 
 
 CCCXLVI. " It is during the subsidence that 
 the blood has a tendency to press with unusual 
 force upon the brain." Dr WOLL ASTON supposes 
 this to be the case, as he feels, at that time, more 
 than at any other, the unpleasant sensation. It 
 is most assuredly during the subsidence that the 
 sensation of nausea is particularly experienced ; 
 and any one that has watched individuals at this 
 time must have observed, that there is an appear- 
 ance not unlike that of fear or dread pictured in 
 the countenance ; the raised chest and anxious 
 expression, indicate one continued inspiration. 
 
 CCCXLVII. If we can by any means divert 
 the attention of the mind by an interesting story 
 or anecdote, the proper order of inspiration and 
 expiration is maintained, and the nausea is 
 unfelt for the time; but allow the individual 
 to look upon the undulating waves, and to 
 attend to his own sensations, and he instantly 
 becomes considerably worse. If we raise a slight 
 alarm of danger, the fainting, retching, and vo- 
 miting almost immediately cease. The natural 
 impulse to preserve life inspires fresh efforts, and 
 these efforts necessarily break the irregular chain 
 of respiration ; expirations, either more perfect or 
 frequent, succeed, and destroy the order of the 
 inspirations, and, as previously explained, diffuse 
 new vigour throughout the system. 
 
 CCCXLVIII. I had an opportunity, a short 
 time ago, of experiencing a slight attack of sickness 
 at sea ; and 1 have also induced it by other 
 
310 THE LAWS OF ORGANIC 
 
 means, that I might carefully examine its influ- 
 ence and the sensations which accompany it. 
 From observation and experience, and from a 
 knowledge of those measures and remedies which 
 are found beneficial in its treatment, I do not 
 hesitate to affirm, that there is, in every stage of 
 nausea, an increased quantity of blood in the chest , 
 and a diminution in the head ; but whether the 
 symptom be present because the head has lost 
 or the chest acquired, it is difficult to say. At 
 this period the face and extremities have less 
 blood than in the state of health ; the tempera- 
 ture of the body k also diminished, because the 
 increased quantity of blood in the chest lessens the 
 capabilities of the lungs to produce the ordinary 
 effects upon it, in accordance with the principles of 
 the first chapter. 
 
 CCCXLIX. Regarding the proximate cause 
 of nausea as depending upon, or accompanied by, 
 an increased quantity of blood in the lungs or tho- 
 racic viscera, when suffering from sea-sickness, I 
 took a small portion of brandy, for the purpose of 
 exciting the internal organs, thereby enabling 
 them to regulate the unequal distribution of 
 blood. A few minutes after its exhibition the 
 various symptoms disappeared, and I felt per- 
 fectly well ; but, in half an hour, the disagreeable 
 sensation returned ; but, by a single repetition of 
 the same stimulus, the healthy conditions of the 
 system were permanently established. 
 
AND ANIMAL LIFE. 311 
 
 CCCL. Children are less frequently sick on 
 board a vessel than adults. They are either de- 
 lighted with the changes and novelties of 'the 
 scene, or they are too unconscious and unsettled 
 to fix their attention on the vary ing objects around 
 them, in consequence of which the respiration and 
 circulation remain in their natural state ; no dis- 
 agreeable impression is transmitted to the senso- 
 rium, nor is the mind, from their years, capable 
 of that reflexion which readily communicates 
 the influence of mental anxiety to the respiratory 
 functions. 
 
 CCCLI. Delicate females are more easily af- 
 fected at sea than the robust of their sex. Me- 
 dicines to which we are unaccustomed often pro- 
 mote sickness, although not intended to produce 
 this effect, but, if frequently repeated, they 
 can be taken with comparative ease ; and the 
 great class of those agents which never enter the 
 system, but which operate exclusively upon the 
 mind, occasion results precisely similar to those 
 which are the consequences of emetic substances 
 in contact with the mucous membrane of the 
 stomach. 
 
 CCCLII. Having divided the remote causes 
 of Syncope into two general classes, I shall say a 
 few words concerning the first, and its subdivi- 
 sions : that is, into those heads in which we have 
 sensations that are derived from the senses and past 
 impress ions , and into pleasurable or painful states 
 of the body. 
 
312 THE LAWS OF ORGANIC 
 
 CCCLIII. Sensations have two sources, the 
 external world, and the various conditions of the 
 animal frame. Those belonging to the first are 
 extremely numerous and complex. Education, 
 habits, and associations, influence very much their 
 operation. To some, the odour of flowers, ge- 
 nerally admired, is disagreeable ; objects that 
 please one offend another. Indeed it is impos- 
 sible to adduce a single instance in which the ex- 
 ternal senses, in different individuals, are similar- 
 ly acted upon by the variety of agents. But if the 
 fragrance of a flower produce syncope in one, it 
 is not because the effect is confined to the senso- 
 rium, but because the organ is powerfully influ- 
 enced, and the impressions it receives are commu- 
 nicated to the respiratory functions ; and it is to this 
 re- action that we are to attribute the cessation or 
 palpitation of the heart. The dissimilarity in the 
 sensibility of different individuals, and in the 
 consequences induced, is to be considered as 
 principally originating in structural modifications 
 which we cannot appreciate. If the mind of one 
 individual be more susceptible than another, and 
 if the relations existing between the heart and 
 lungs be extremely delicate, from causes which 
 were stated in the preceding chapter, the mind 
 will be more readily excited or depressed, and 
 every thing within the sphere of its influence 
 will be proportionately disturbed. 
 
AND ANIMAL LIFE. 313 
 
 CCCLIV. I have previously endeavoured to 
 show that the heart is not directly affected by 
 the mind through the intervention of nerves, but 
 by its action upon the function of respiration. The 
 muscles of respiration are partly subject to the in- 
 fluence of the will, and partly free from its opera- 
 tion. The involuntary influence is that power 
 which is particularly called into action by our sen- 
 sations, whatever be their origin or character. If of 
 an inspiratory nature, the ordinary motion of the 
 chest is disordered, and the consequence of this 
 change is, that a quantity of blood greater than 
 what is natural is determined to the thoracic or- 
 gans, creating palpitation from the increased de- 
 mand made upon the heart, or complete cessation, 
 from the great oppression. 
 
 CCCLV. When fear makes a powerful im- 
 pression upon the mind, the individual draws a 
 deep sigh, or seems to give a continued inspira- 
 tion ; faintness is probably felt ; and the mode of 
 inspiring being but slightly interrupted by the 
 occasional or imperfect expirations, the lungs and 
 heart receive more blood than they are capable 
 of transmitting with accustomed regularity. It 
 is the relation of quantity to the capacity and ener- 
 gy of the heart that explains in part the definition 
 of CULLEN, " Motus cordis imminutus vel ali- 
 quandiu quiescens." As the susceptibility, sen- 
 sations, ancl organic adaptations are not alike in 
 
314* THE LAWS OF ORGANIC 
 
 any two individuals, the effects will necessarily 
 be various. 
 
 CCCLVL Intense emotions of pleasure not 
 unfrequently occasion syncope ; this arises from 
 the balance of the mental powers being disturb- 
 ed by causes that have acted almost exclusively 
 upon that part of our constitution appropriated 
 to sensation. The consequence is promoted by 
 whatever is exquisitely painful or agreeable. The 
 effects of these opposite feelings differ but slight- 
 ly, if at all, in the vividness of their extremes. 
 
 CCCLVII. Syncope is not unfrequently pro- 
 duced by heat, but the general application of this 
 power is not so apt to occasion it as when it is 
 partially employed. When the whole frame is 
 influenced at the same moment, either from ex- 
 ercise or any other means, there is an equality 
 even in the altered circulation which prevents 
 the formation of, or rather does not create that 
 peculiar sensation, the reaction of which, upon 
 the respiratory function, is indispensable to give 
 rise to this affection. When one part of the sys- 
 tem is individually excited, this almost immedi- 
 ately destroys the harmony of the circulating 
 powers, the derangement of which is precursory 
 to mental and corporeal changes connected with 
 the production of syncope. 
 
 CCCLVIIL The general application of cold is 
 rarely or never the cause of syncope, however, 
 not from the reasons which have been assigned 
 
AND ANIMAL LIFE. 315 
 
 for the operation of increased temperature, but 
 on account of the diminished sensibility of the 
 nervous system. The blood which is determined 
 internally would probably give rise to syncope or 
 vomiting, but the cold has, at the same time, 
 blunted the susceptibility of the mind to impres- 
 sions by the quantity of vital fluid transmitted 
 to the internal organs, and by its less stimulating 
 properties. 
 
 CCCLIX. Fatigue is familiarly known to pre- 
 dispose to syncope, and the cause of this is obvi- 
 ous ; when the mind or body has been long ex- 
 erted, debility is experienced. By excessive ex- 
 ercise of every kind the promptitude and per- 
 fection of many functions essential to life are en- 
 feebled or constrained ; weariness is indicated by 
 sighs, y awnings, and irregular respiration ; a sense 
 of swooning or lightness succeeds ; and as these 
 symptoms augment the paroxysm gradually ap- 
 proaches. CHAMBERET says, " Dans toutes ces 
 circonstances, la faiblesse et la fatigue du cceur, 
 suite de la faiblesse et de la fatigue generales, 
 sont la cause de la suspension de 1'action de cet 
 organ et de la syncope, par consequent."* Ge- 
 neral weakness and debility do not produce weak- 
 ness and fatigue of the heart in the manner this 
 author imagines. General weakness and debility, 
 particularly if brought on by great muscular ex- 
 
 * Dictionnaire des Sciences Medicales, p. 89. Vol. 54. 
 
316 THE LAWS OF ORGANIC 
 
 ertion, have a tendency to determine the blood 
 to the internal organs. Exercise, as long as it 
 was continued with vigour, maintained the na- 
 tural state of the circulation ; but the necessary 
 repose consequent on excessive exercise deprives 
 the system of those stimuli that previously sus- 
 tained the equality of the circulation throughout 
 the body ; and the absence of these, conjoined 
 with the above depressing feelings, speedily pro- 
 duce an overcharged state of the lungs and heart. 
 
 SECT. II. An examination of the causes which oc- 
 casion Syncope by changing the ordinary course or free- 
 dom of the circulation. 
 
 CCCLX. Structural alterations in the heart, 
 or in parts contiguous to it, are among the most 
 frequent causes of syncope ; but having, in the 
 chapter on Palpitation, treated at considerable 
 length of those organic changes which predispose 
 to that affection, it is unnecessary to repeat the 
 same as tending to give rise to the disease we 
 now investigate. The proximate cause of the 
 two diseases is the same, the only difference be- 
 tween them is in the degree and not in the na- 
 ture of it. 
 
 CCCLXI. Syncope is most generally witness- 
 ed in the simple operation of bleeding. From 
 the sensibility of the patient, it sometimes pre- 
 
AND ANIMAL LIFE. 317 
 
 cedes the abstraction of blood, or occurs during 
 its flow ; it more frequently takes place when the 
 object of the surgeon is nearly accomplished. 
 
 CCCLXII. It is believed when an individual 
 faints during the act of bleeding, that it is be- 
 cause the blood has left the heart. I shall attempt 
 to show that it is because the blood has flowed to 
 the heart, and not from it. 
 
 CCCLXIII. If the organs of the animal eco- 
 nomy were so finely adjusted as the common opi- 
 nions of mankind'on this subject would lead one to 
 believe, we could scarcely expect that one patient 
 would be able to lose sixty ounces of blood without 
 this loss being succeeded by syncope, when, in 
 another, the loss of two or three ounces is almost 
 instantaneously followed by this affection. It 
 seldom or never happens till a strong impression 
 be received by the sensorium, and subsequently 
 transmitted to the respiratory organs. The sur- 
 geon has no difficulty in ascertaining the symp- 
 toms which precede its occurrence ; the occasion- 
 al deep sighs, the irregular, inspiratory character 
 of the respiration, and the paleness or flitting co- 
 lour of the countenance, are a few of those 
 changes which indicate its approach. I have re- 
 peatedly said, that sighs and inspirations deter- 
 mine the blood upon the internal viscera : the na- 
 ture and preponderance of these acts have invari- 
 riably this tendency. 
 
318 THE LAWS OF ORGANIC 
 
 CCCLXIV. Syncope has not any relation to 
 the quantity of Mood which is drawn, its only 
 relation is with the sensations which precede, at- 
 tend, or follow the operation. 
 
 CCCLXV. On tying the arm," says Dr 
 MASON GOOD, " a considerable stream of supply 
 is cut off, and ten ounces of blood flow, in per- 
 haps five minutes, into a basin, which would have 
 otherwise flowed into the heart in the same pe- 
 riod of time. The volume of blood is hence di- 
 minished, and the heart must collapse or contract 
 itself in the same proportion."* If the heart con- 
 tracted according to the loss of blood, one would 
 think that its contraction or collapse would be 
 very great when it loses six times the quantity 
 mentioned by Dr MASON GOOD. But the heart 
 is not thus mechanically affected in its action ; 
 it may be influenced by the diminution, but it is 
 only so far influenced, in the first place, as to ex- 
 cite an unpleasant sensation, the influence of which 
 disorders the respiratory functions, causing sighs 
 and deep inspirations ; and it is these acts that have 
 the tendency to bring an unusual quantity of blood 
 to the chest from the surface of the body, the inferior 
 and superior extremities ; so that during the pre- 
 cursory stage of the paroxysm, and particularly 
 during the Jit itself, the lungs and heart have more, 
 and not less, of the sanguineous fluid. 
 
 * The Study of Medicine, Vol. III. p. 506. Edit. Prima. 
 
AND ANIMAL LIFE. 319 
 
 CCCLXVI. It is a very wise provision of Na- 
 ture that such a state of things exists. If the 
 heart and lungs had less blood at the time of the 
 paroxysm, death would inevitably be the conse- 
 quence. Suppose it to be at rest, from great loss 
 of blood, agreeably to the general opinion,* can 
 we conceive the possibility of its revival ? Its on- 
 ly stimulus is the blood; it has ceased to act be- 
 cause it was destitute of this principle : then, it 
 is obvious, that it has no other source to supply 
 its necessities, and therefore it must continue in 
 this state of repose. But, suppose it to have 
 been oppressed by a superabundance, in accord- 
 ance with the principles proposed, and the diffi- 
 culties vanish. Respiration being suspended, a 
 further accumulation of blood is prevented. The 
 muscular fibres of the heart are in contact with 
 the blood, which more or less stimulates them to 
 contract ; and how trifling soever this contraction 
 may be, it is gradually overcoming the load by 
 which it is oppressed, and the organ is not sup- 
 plied with a fresh burden, as respiration is inac- 
 tive, on which the moving powers of the sangui- 
 ferous system depend. 
 
 CCCLXVII. The position in which a patient 
 soonest revives is that which is best adapted to 
 relieve the lungs and heart. The individual is 
 recommended to be placed upon an inclined 
 plane, with the head a little higher than the 
 trunk. In this way, the blood, however slight 
 the impulse which propels it, has its natural dis- 
 
320 THE LAWS OF ORGANIC 
 
 position to circulate promoted. The circulation, 
 by degrees, extends itself to the head, extremi- 
 ties, and surface of the body, and it is evident that 
 recovery will be proportionate to the facility with 
 which the distribution to every other part of the 
 system is effected, as it tends to remove the con- 
 gested condition of the internal viscera and vessels. 
 If the head were placed much lower than the 
 trunk the blood would flow with still greater ease 
 from the chest to the brain ; but this change, in- 
 stead of relieving the powers of life, would pro- 
 bably destroy them, by preventing the return of 
 sensorial sensibility, indispensable to the recovery 
 of the individual. 
 
 CCCLXVIII. In the operation of paracente- 
 sis abdominis, syncope very often takes place, 
 particularly if the water be evacuated copiously 
 and suddenly. It is supposed that syncope oc- 
 curs, because the internal vessels have lost their 
 accustomed pressure. Dr MASON GOOD observes, 
 when vessels have been pressed upon, as in drop- 
 sy of the abdomen, that they " suddenly acquire 
 a power of dilatation." There are several reasons 
 which induce me to dissent from this opinion. 
 
 a. Vessels of the head, in Chronic Hydroce- 
 phalus, must be considerably more compressed 
 occasionally, than those of the abdomen in Asci- 
 tes, if either be compressed. The bones of the 
 skull do not so readily accommodate themselves 
 to the power from within, as the parietes of the 
 
AND ANIMAL LIFE. 321 
 
 abdomen ; it is therefore probable, if pressure 
 affected the vessels to the extent which is gene- 
 rally imagined, that the circulation would be en- 
 tirely obstructed, or, at least, evidently disturbed, 
 which, however, is far from being the case. 
 
 b. If internal pressure diminished the calibre 
 of the vessels to the extent supposed, we should 
 certainly expect great disorder in the sanguife- 
 rous system, whenever this power was even 
 moderately exerted. We have seldom the en- 
 larged and oedematous extremities till general 
 debility be present ; and this condition is often 
 remarked when we have no internal pressure to 
 account for it. 
 
 c. The only function immediately relieved by 
 the operation of paracentesis abdominis, is that 
 of respiration. It is extremely difficult, or almost 
 impossible, to breathe in a supine posture when 
 the hydropic accumulation is considerable. 
 
 CCCLXIX. Whatever alteration the abdomi- 
 nal vessels may suffer from the watery evacua- 
 tion, I am persuaded that the change, neither 
 directly nor indirectly, is the cause of syncope. 
 During the collection of the fluid the diaphragm 
 has been pushed up, presenting an almost un- 
 yielding convex surface to the lungs. The cavity 
 of the thorax, the capacity and mobility of the 
 lungs, have consequently been much lessened and 
 impeded. When the fluid is evacuated, the 
 diaphragm almost instantly resumes its proper 
 x 
 
THE LAWS OF ORGANIC 
 
 situation and form ; the atmospheric air rushes 
 in to dilate the cells, which had previously been 
 compressed, or almost obliterated ; and the blood 
 likewise, jinding less resistance in the chest, flows 
 towards it in greater quantity than usual producing 
 palpitation of the heart, if the quantity be slight ; 
 if inordinate, syncope, from the great oppression. 
 
 CCCLXX. The alterations which the ab- 
 domen undergoes in parturition may be re- 
 garded as operating in the same manner upon 
 the chest and its contents, and we have some- 
 times the same effects ; but Nature, by certain 
 wise provisions, has diminished very much the 
 liability of the female to such occurrences. The 
 first five or six months of gestation are attended 
 by a greater difficulty of breathing and thoracic 
 derangements than the remainder of the period ; 
 and this arises from the situation of the foetus, 
 which is principally confined to the upper part 
 of the abdomen, and therefore more injurious to 
 the respiratory function ; but, from this time to 
 the period of confinement, it gradually descends, 
 and occupies the lower region of the abdominal 
 cavity, relieving the function of respiration. 
 During the pains of parturition the foetus de- 
 scends still more, till at last it reaches the pelvis. 
 The gradual changes during labour having the 
 tendency to effect this end, the sudden expulsion 
 of the fcetus is not accompanied by serious 
 results ; because the respiratory organs have, by 
 
AND ANIMAL LIFE. 328 
 
 degrees, in this manner, been protected from 
 effects that would otherwise have destroyed or 
 endangered life. 
 
 CCCLXXI. The various stages of gestation, 
 and the act of parturition, are among the best 
 illustrations that can possibly be brought forward 
 of the origin, transmission, and influence of sen- 
 sations, and of physical changes to which the 
 delicate frame of the female is highly susceptible. 
 
 x 
 
324 THE LAWS OF ORGANIC 
 
 CHAP. XV. 
 
 Physiology of Passion. 
 
 SECT. I, The Seat of Passion. 
 
 CCCLXXII. THE endeavour to trace the 
 connection between mind and matter has been 
 frequently made; but the inquiries to which 
 it has led have added little to the most ancient 
 opinions concerning Passion. Anatomy and phy- 
 siology have certainly made us better acquainted 
 with the structure and functions of organs, and 
 with the mode in which these reciprocally act on 
 each other ; but, instead of removing the diffi- 
 culties which envelope the nature of this subject, 
 they have tended to increase them. A superior 
 knowledge of the nervous system has enabled 
 some to form many fanciful theories concerning 
 the operations of mind, such as the oscillation of 
 the nervous fluid, the peculiar action of ganglia, 
 and the direct communication of different nerves. 
 
 CCCLXXIII. When an investigation is of 
 trifling moment in its results, we may occasion- 
 ally allow the ingenious mind to indulge in its 
 visionary speculations ; but when the interest of 
 humanity is a prominent object, the flights of 
 imagination ought not to take the place of sound 
 
AND ANIMAL LIFE. 325 
 
 reasoning and correct deductions. The speculative 
 physiologist and philosopher more frequently re- 
 tard than promote the progress of science. The 
 splendour of great names attached to systems or 
 opinions gives these authority and currency, not 
 only when they are well founded, but even when 
 they are gratuitous assumptions. 
 
 CCCLXXIV. Since we know nothing of the 
 nature of mind, and almost as little of certain 
 properties belonging to the nervous system, we 
 are by no means prepared to develope principles 
 that necessarily suppose a knowledge of ultimate 
 causes. Although certain secrets of our consti- 
 tution appear impenetrable, yet it is within the 
 comprehension of human faculties to observe the 
 succession of phenomena, to mark their order 
 and importance, and, by the light which they 
 afford, to distinguish, in a clear and consistent 
 manner, the relation existing between the mind 
 and the vital organs of the body. 
 
 CCCLXXV. The labour of tracing conse- 
 quences to their source is tedious and irksome 
 to the generality of individuals. The progress 
 of science, thus regulated and measured by gra- 
 dual steps, is necessarily slow, and the object 
 attained appears trivial, unless viewed in con- 
 nection with others of the same or similar cha- 
 racter. It would seem the natural disposition 
 of mankind to systematize, rather than to collect 
 and arrange individual facts by close observation 
 
26 THE LAWS OF ORGANIC 
 
 and unprejudiced judgment. The eye of taste 
 delights to look upon an edifice complete and 
 beautiful in proportion, possessing a variety of 
 qualities adapted for embellishment or utility, 
 and the mind is similarly constituted : the crea- 
 tions of others, or its own, seldom please unless 
 the plans or principles unfolded are extensive 
 and harmonious in all their parts, a circumstance 
 which seldom occurs, even in appearance, except 
 in those cases in which theory or hypothesis is 
 employed to fill up the interstices or vacuities 
 left by sound reasoning or experimental philo- 
 sophy. 
 
 CCCLXXV1. In the following attempt to in- 
 vestigate the connection between mind and body, 
 I have not been guided by any opinion respect- 
 ing the nature of the former ; it is sufficient for 
 my purpose to ascertain that ideas and sensations 
 are properties of the one, as motion and sensi- 
 bility are the endowments of the other. 
 
 CCCLXXVII. The views which I bring for- 
 ward are less the production of the closet than 
 the result of close and patient observation on 
 man in the busy theatre of the world, where he 
 is continually agitated by the vicissitudes of for- 
 tune or the ever-changing incidents of life. I 
 have attended more particularly to the extremes 
 of mental emotion than to the slighter and more 
 continued influence of less evident feelings, as I 
 propose to reason only from effects ; but what- 
 
AND ANIMAL LIFE. 327 
 
 ever laws or principles maybe advanced to explain 
 one class of phenomena will apply equally well 
 to another, whose only difference lies in the de- 
 gree of the cause. 
 
 CCCLXXVIII. One part of the philosophical 
 world is disposed to regard mind as an immater- 
 rial principle, independent of the direct control 
 of organization ; another would seem to measure 
 its profundity, or estimate its limits, by the quan- 
 tity of matter presented to the eye. In subjects 
 of this kind it is difficult to make even an ap- 
 proximation to truth, as the phenomena of which 
 we treat are inexplicable on any known law ? and 
 are too mysterious to be fathomed by the facul- 
 ties of man, in a manner sufficiently precise to 
 enable him to refer them to certain well esta- 
 blished principles of the mental constitution. 
 
 CCCLXXIX. Effect and cause in the animal 
 economy cannot be compared to those arising 
 from ordinary physical adaptations. In the lat- 
 ter we have a clear and distinct idea of the rela- 
 tion existing between the two ; but in the former 
 the conception is indefinite and inconclusive, as 
 a variety of causes predispose to produce one 
 great and evident result, the nature and opera- 
 tion of which are not understood : or if one agent 
 be considered the efficient cause, our knowledge 
 even of this will necessarily be confined to its 
 most obvious influence, which will give us 
 no insight whatever into its own nature or 
 
328 THE LAWS OF ORGANIC 
 
 mode of action ; and therefore the simplicity of 
 material arguments becomes complex as soon as 
 it presumes to explain the grounds of its own 
 existence. 
 
 CCCLXXX. Passion, by which term I mean 
 every violent perturbation of the mind, has its 
 origin undoubtedly in the brain. Different phy- 
 siologists have given it different seats ; by some 
 it is imagined to reside in the above-mentioned 
 organ, by others in the ganglia of the sympa- 
 thetic nerve, by BICHAT, and many distin- 
 guished individuals, in the viscera of the body. 
 Passion may be considered a part of the mind, 
 and is as essential for the continuance and regu- 
 larity of every function of the system as the in- 
 tellectual qualities themselves. 
 
 CCCLXXXI. We are so constituted by na- 
 ture, that our feelings and mental powers reci- 
 procally act on each other. Reflection, as it un- 
 folds the baseness of those who possessed our 
 confidence, excites our various passions, and 
 in how many instances do the latter give energy 
 to the desponding exertions of the former ! 
 
 The intimate connexion between these oppo- 
 site states of the mind, strengthens the opinion 
 that they both possess the same general organ, 
 or at least one formed of similar materials. 
 
 CCCLXXXII. We have not only proofs in 
 support of this supposition in the observations 
 of their ordinary actions, but we arrive almost at 
 
AND ANIMAL LIFE. 329 
 
 demonstration in tracing their consequences in 
 an extreme development. At one time our pas- 
 sions destroy the balance of the intellectual facul- 
 ties, at another these annihilate the proper mani- 
 festations of the former ; and as insanity is to 
 be attributed to one or both of these conditions 
 of aberration, it is certainly most philosophical 
 to refer every species of this affection to the dis- 
 turbance of the sensorial functions. The warmest 
 advocates for visceral passions, if I may be al- 
 lowed the term, would be unwilling to treat 
 mental diseases, even if they could prove the 
 dependence of these on violent perturbation, on 
 those principles which have a particular applica- 
 tion to the different organs of the system. 
 
 CCCLXXXIII. In individuals who have 
 suffered long from insanity, the brain is fre- 
 quently found, after death, to exhibit indications 
 of disease ; and although we are unable to de- 
 tect them in all instances, the apparent absence 
 of such is no proof whatever that they do not 
 exist. Before we can decide on the morbid state 
 of any part of the body, we must previously 
 be acquainted with those appearances character- 
 istic of health. This knowledge is seldom accu- 
 rate or extensive in regard even to those organs 
 whose functions are evident, and whose structure 
 is easy to explain ; but this knowledge, in relation 
 to the various offices belonging to the nervous 
 system, is still more uncertain and superficial. 
 
330 THE LAWS OF ORGANIC 
 
 CCCLXXXIV. The external form of the head 
 has of late years been much studied in the spirit 
 of experimental philosophy, and is now divided 
 into general and individual sections. General ob- 
 servations go far to support the correctness of the 
 first, viz. the division into those regions appropri- 
 ated to intellect, sentiments, and feelings. If these 
 principles (in their outline) be received as legiti- 
 mate conclusions, the seat of the passions becomes 
 as obvious as that of vision. 
 
 CCCLXXXV. The opinions and actions of 
 the vulgar have a greater influence in controlling 
 the progress of philosophy than is generally im- 
 agined. It is almost impossible, however ta- 
 lented the mind, to investigate causes, and to 
 weigh effects, unbiassed by the many motives and 
 considerations which are borrowed, perhaps un- 
 consciously, from society. The truth of this 
 observation is illustrated in the manner in which 
 BICHAT has treated the seat of passions, believ- 
 ing them to belong to the different viscera. To 
 prove the soundness of his views, he could not 
 appeal to experiments, by which he, on other 
 occasions, has distinguished himself, and there- 
 fore was confined to reasoning, which is princi- 
 pally founded on the influence of emotions on 
 the action of the heart, and the expressions of 
 individuals under such circumstances. 
 
 CCCLXXXVI. In fear, the countenance is 
 pale, the lips tremble, and the heart palpitates; but 
 
AND ANIMAL LIFE. 331 
 
 if, from observing the effects of this passion, he is 
 induced to place it in the latter organ, he may 
 as logically refer it to any other part of the frame 
 if excited or depressed* A difference in the de- 
 gree of the consequences occasioned, is insuf- 
 ficient to authorize a distinction of such into 
 causes and effects, unless in relation to each other, 
 and in reference to the mind as the primary 
 agent. 
 
 CCCLXXXVII. Although palpitation of the 
 heart is a concomitant of fear or anger, yet it 
 is not a proof that either of these has its seat in 
 the thorax, nor does the general reference of 
 mankind to the region of palpitation yield any 
 support whatever to this opinion. The learned 
 and the illiterate act equally from the impulse 
 or feeling of the moment, in regard to the ex- 
 ternal expressions of nature. The hand is fre- 
 quently placed over the heart when we are agi- 
 tated by the most tender or elevated passions, 
 whether in solitude or society ; and when we wish 
 to communicate to others a knowledge of our 
 sentiments, the same sign is employed. In the 
 first instance, it is almost unconsciously applied 
 to the heart in the second, because the indi- 
 vidual is aware that he speaks most eloquently to 
 his hearers when he brings into action the most 
 significant of conventional symbols ; and this is a 
 character as well understood as paleness, or redness, 
 or the expressions of the tongue. 
 
33 THE LAWS OF ORGANIC 
 
 CCCLXXXVIII. In the early stages of civili- 
 zation it is not improbable that passion was sup- 
 posed to reside in the chest, as a peculiar sensa- 
 tion of the heart never failed to accompany the 
 stronger emotions of the mind ; and in those ages 
 most distinguished for refinement and taste the 
 same ideas were entertained, not because men 
 had reflected on the origin of their feelings, and 
 were therefore satisfied of the language in use to 
 express them, but simply because they knew al- 
 most as little as those that had preceded them of 
 the functions of animal and organic life. 
 
 CCCLXXXIX. The different epithets in con- 
 stant use to designate a good or bad heart, or the 
 peculiarities of the head, have arisen from the 
 same principle as that which gives a visceral local- 
 ity to the passions. The greater part of violent 
 emotions being placed in the thorax, and indi- 
 viduals being good or bad according to the deve- 
 lopment or direction of such, and, still further, 
 mankind being supposed to err from the impro- 
 per government of such feelings, it became 
 proverbial to say that the heart was virtuous or 
 wicked. 
 
 CCCXC. These general observations soon 
 led to others of a more minute description. The 
 heart being regarded as the seat of passion, it was 
 remarked that the most generous and liberal cha- 
 racters were those whose feelings were readily 
 excited by the variety of external objects, and 
 that such individuals had the open, ruddy, and 
 
AND ANIMAL LIFE. 333 
 
 kindly expression of countenance, as indicated 
 by the sanguineous temperament, agreeably to 
 their undigested notions concerning the relation 
 existing between the heart and the moral action 
 or sentiments of the mind. 
 
 CCCXCI. That physiologists in modern 
 times should have been so far regulated by vul- 
 gar opinion as to adopt it in their arguments, in 
 support of the same views, is somewhat extraor- 
 dinary. If the organs which were endowed with 
 passion had exhibited no obvious functions, it 
 might then have been reasonable to attribute to 
 them the origin of every emotion ; but since 
 there is no viscus in the chest thus unoccupied, 
 we cannot allow the imaginative mind to indulge 
 in its fancies at the expence of common sense. 
 
 SECT. 11. The Phenomena and Physiology of Passion. 
 
 CCCXCII. THERE are few terms more fre- 
 quently employed, or more abused, than that of 
 passion. It is common to bestow it on a variety 
 of states of the mind that have not the least si- 
 militude to each other, either in the causes by 
 which they are determined, or in the effects by 
 which they are characterized. If it be defined a 
 perturbation of the mind, accompanied by visible 
 alterations in any of the general systems of the 
 body, a great number of mental conditions will 
 
334 THE LAWS OF ORGANIC 
 
 necessarily be excluded from the catalogue of our 
 passions. If we analyse the constitution of the 
 mind, we shall find it extremely complex, even 
 in regard to those faculties which are more or less 
 distinguished by sensation ; but if we closely at- 
 tend to the expressions and actions of individuals, 
 we shall be enabled to form certain general divi- 
 sions of the mental states of passion. 
 
 CCCXCIII. It is obvious that passions excite 
 or depress, and therefore they possess imme- 
 diate effects upon the system ; and unless we 
 observe these effects, we are not entitled to con- 
 clude that the conduct of an individual is influ- 
 enced by passion. Ambition, pride, and vanity, 
 do not display any of those marks by which we 
 understand a person to be warmly exasperated 
 or deeply grieved ; we have neither the florid nor 
 pale countenance, the hurried nor retarded res- 
 piration, the pulse bounding, or small and fre- 
 quent : no indications are present belonging to 
 the system by which we know that such are the 
 characteristics of the mind. 
 
 CCCXCIV. From the above and other reasons, 
 passions are divided into those that Excite and 
 those that depress, and the different conditions of 
 the mind that cannot be referred to either of 
 these classes are designated mental peculiarities. 
 The consistency of this general division will pro- 
 bably be appreciated when the sentiments con- 
 cernino' each subdivision have been fully stated. 
 
AND ANIMAL LIFE. 335 
 
 CCCXCV. The principal passions, which are 
 stimuli to the whole system, are joy, anger, hope, 
 and love ; and the chief of those that act as seda- 
 tives are fear, wonder, melancholy, grief, and jea- 
 lousy. Ambition, pride, humility, avarice, and 
 vanity, are included in the class of mental pecu- 
 liarities. The distinguishing character of the 
 two former is, that they are directly excited by 
 immediate objects, and the extent of the influence is 
 measured by the obvious changes induced ; whereas 
 it is almost impossible, by any external manifesta- 
 tions, to assert the existence of the latter. Our 
 passions are seldom entirely suppressed; they 
 may be controlled : but ambition and pride are 
 dispositions of the mind that are sometimes alto- 
 gether concealed, and, as they produce no parti- 
 cular consequence upon the system, we cannot 
 estimate precisely their nature or degree. The 
 ambitious man may employ the greater part of 
 his life in endeavouring to exalt himself, without 
 having any of his corporeal functions deranged. 
 Deliberate reflection on the best means likely to 
 promote his interest, or the attainment of his 
 wishes, neither excites nor depresses the organic 
 system ; and therefore the principle by which he 
 is actuated ought not to be regarded in the light 
 of passion. The same observations apply to the 
 rest included in the same class. 
 
 CCCXCVI. When I speak of passions, I 
 allude to these as depending, equally with men- 
 
336 THE LAWS OF ORGANIC 
 
 tal peculiarities, on the natural constitution of 
 the mind. Our tastes and susceptibilities are 
 certainly very dissimilar ; and although some are 
 disposed to consider such as the consequences of 
 civilized society, or of circumstances, yet it is more 
 consistent with my own experience and reflec- 
 tion to attribute the variety, in degree and cha- 
 racter, to a fundamental difference in the confor- 
 mation of our minds. As this opinion is the one 
 most generally entertained, and as its full deve- 
 lopment does not belong to the subject in ques- 
 tion, it is unnecessary in this place to investigate 
 its merits. 
 
 CCCXCVII. In glancing at the exciting pas- 
 sions individually, it is evident that these differ 
 almost as much among themselves as they do 
 from those that belong to the other class. Hope, 
 in its prospective view, is one of the most gentle 
 of excitants : it disburdens the present of its 
 weariness or misery, and embellishes the future 
 with all that imagination can create. There are 
 few clouds which it cannot disperse, and few ob- 
 jects which it cannot brighten ; but its influence 
 is so mild that it may somewhat be likened to 
 that of the moon, which diffuses more light than 
 warmth. Yet this passion, although apparently 
 so feeble, is of great importance to the animal 
 economy ; it is a constant mid benignant stimulus to 
 the mind, and, as the involuntary actions of respi- 
 ration are regulated by the latter principle, it is the 
 
AND ANIMAL LIFE. 337 
 
 indirect means of distributing throughout the sys- 
 tem blood of a more invigorating quality. 
 
 CCCXCVIII. Joy excites the mind more pow- 
 erfully than the preceding passion ; or, from being 
 more connected with feeling than intellect, im- 
 presses its effects more strongly upon the coun- 
 tenance. 
 
 CCCXCIX. Anger is the most violent of all men- 
 tal stimuli, and, as it is characterized by a greater 
 variety of phenomena, it will illustrate more clear- 
 ly the connection of mind and matter. Of what 
 kind soever be the- object that awakens our feel- 
 ings, its primary action is upon the mind ; and 
 when an individual receives an insult, or is vehe- 
 mently exasperated, we observe the fluency with 
 which he pours forth his sentiments, the hurried 
 state of his respiration, and the muscular exer- 
 tions employed to enforce the character of his 
 feelings. His volubility of tongue changes the 
 regular order of respiration. Expirations are more 
 numerous and complete than inspirations the ef- 
 fect of which is, that the blood becomes better 
 oxygenated, from the quantity within the chest 
 being less than natural. The blood, having un- 
 dergone more perfect chemical changes, becomes 
 more stimulating to the heart ; the pulsations of 
 this organ are more frequent and forcible ; the 
 increase of contraction, conjoined with augment- 
 ed muscular exertion, explain the rapidity of the 
 circulation and the highly florid colour which it 
 Y 
 
338 THE LAWS OF ORGANIC 
 
 gives to the face. At this stage of anger, it is 
 not uncommon for the heart to palpitate ; and 
 this irregularity arises from the more stimulating 
 nature of the blood. The internal cavities of 
 this organ, and the coronary arteries, receive a 
 more than usual excitation, and therefore the 
 function to which they contribute is influenced 
 accordingly. 
 
 CCCC. If the violence of anger be long con- 
 tinued, we remark a different train of symp- 
 toms. The countenance is swollen, and of a 
 livid aspect ; the respiration becomes deep and 
 laborious, and the individual often applies his 
 hand to the prascordial region, from the pain or 
 oppression which he feels in this situation. Ex- 
 pirations having exceeded inspirations to a pain- 
 ful extent, necessarily prevent the free return 
 of blood from the head and other parts of the 
 body ; and this fluid, in a short time, accumulates 
 and occasions that bloated expression to which I 
 have alluded. 
 
 CCCCI. I have spoken only of one species 
 of anger. There is another* which is more 
 rare, and has often been fatal, from destroying 
 the action of the heart. It is that in which an 
 individual scarcely utters a word, and in which 
 he exhibits extreme paleness. When an emotion 
 is very intense, it seldom spends itself in idle 
 words ; it absorbs too much of the mind to vent 
 its indignation in momentary expressions ; and, 
 instead of being a stimulant it becomes a seda- 
 
AND ANIMAL LIFE. 339 
 
 tive to the system. Expirations are not excited 
 as in the preceding instance, but the person 
 affected draws deep inspirations ; and these hav- 
 ing the tendency to bring the blood towards the 
 chest, they diminish the quantity in the face and 
 surface of the body ; and the superabundance in 
 the thorax quickly causes palpitation or syncope, 
 from the action of the heart being oppressed. 
 
 CCCCII. I have witnessed one or two 
 well-marked instances of the latter description of 
 anger ; and these accord with the principles pro- 
 posed to explain them. The curled and tremb- 
 ling lip, the scowling eye, and the fixed features, 
 are observed ; and, at the same time, the chest 
 deeply heaves, as if to muster force or suppress an 
 inward feeling. If the cause of the emotion were 
 unknown, and a few of its external traits were 
 absent, the individual would be supposed to suf- 
 fer from fear : the respiration and circulation are 
 influenced in a similar manner in both cases. 
 
 CCCC1IL Having pointed out briefly the 
 mode in which the heart is acted upon by those 
 passions that powerfully excite it, is clear there 
 is not that mysterious connexion between the 
 mind and body so universally believed. Every 
 functional derangement of the heart, if the effect of 
 passion, is occasioned by a primary disorder in the 
 regularity of the respiratory functions) and is never 
 the consequence of a nervous communication between 
 
340 THE LAWS OF ORGANIC 
 
 the brain and the nerves which supply this organ* 
 The following objections may, probably, be 
 brought forward against the present view: 1. 
 That the heart is, at times, instantaneously affected 
 with palpitation. %. That the order of respiration 
 is frequently deranged without being accompanied 
 by a corresponding alteration in the heart.* In 
 answer to these and similar objections, I may 
 here remark, that there are different degrees of 
 palpitation, agreeably to the intensity of the 
 causes that produce them ; and although we speak 
 of palpitation as a general term well understood, 
 yet we must not forget that the recognition of 
 this abnormal action depends as much upon the ca- 
 pability of the mind to attend to its sensations as 
 upon the irregularity in the function of the heart. 
 If we were always equally sensible to every 
 change of this organ, it is not improbable that 
 we should become so familiarized with the va- 
 riety of its pulsations as to be entirely unsus- 
 ceptible of its present occasional disorders. The 
 heart is beating more violently when the system 
 is stimulated by spiritous liquors, by running, 
 vehement speaking, and many other kinds of 
 muscular exercise, than in the generality of those 
 cases in which we complain of palpitation; but, un- 
 der those circumstances, the mind is also excited, 
 
 * For the better understanding and appreciating the causes 
 which disturb the thoracic organs, the reader is referred to the 
 Chapters on Palpitation and Syncope. 
 
AND ANIMAL LIFE. 341 
 
 and, on this account, is not always sufficiently at 
 rest to analyze feelings of this nature. The ner- 
 vous patient, whose every moment is devoted to 
 the discovery of new or uncommon pains, regards 
 the palpitation of the heart as the most constant 
 and troublesome of all symptoms ; but when we 
 apply the stethoscope to the chest, it is not un- 
 usual to find the action as regular as in the state 
 of health. 
 
 From these remarks, it is manifest that palpi- 
 tation, in many instances, may be supposed to 
 exist where there is no increased or irregular 
 action of the heart, but a greater susceptibility 
 of the mind to the ordinary operations of the sys- 
 tem. 
 
 CCCCIV. Several cases are on record of indi- 
 viduals who were able to arrest the motions of 
 the heart, shewing that these were under the 
 direction of the will. It is impossible to doubt 
 the fact, bqt the manner may be called in ques- 
 tion. From the great power we possess in ex- 
 citing or depressing respiration, and the direct 
 influence this has upon every state of the heart, 
 it is probable that the action of the organ was 
 stopped by exercising the will upon respiration, 
 and not upon the heart. We are not to infer from 
 this surmise, that every individual is capable of 
 performing the same act, nor do I imagine it 
 possible to be taught ; because I believe, when- 
 ever this phenomenon occurs, that there is some 
 
342 THE LAWS OF ORGANIC 
 
 defect or peculiarity in the organization of the 
 heart itself, on which account it is more liable to 
 be deranged by every alteration in the respira- 
 tory function. If we suppose its cavities to want 
 their proper proportions, it will be easy to con- 
 ceive that a quantity of blood, more abundant 
 than usual, will enfeeble or control its action ; 
 or some other predisponent condition may exist 
 of which we have no idea. 
 
 CCCCV. I have placed Love among the pas- 
 sions of this class, which we have hitherto con- 
 sidered : but it is difficult to say to what divi- 
 sion it properly belongs ; it varies according to 
 the nature of our feelings and motives, the at- 
 tractions of the object, the difficulties opposed 
 to our wishes, and many other circumstances not 
 easy to enumerate. This passion is at one time 
 gentle and soothing, at another it distracts by 
 its violence, or depresses by its fears ; but every 
 diversity which it displays may be referred to 
 one of the two general classes. 
 
 CCCCVI. From this very brief account of the 
 way in which exciting passions derange the cir- 
 culatory system, and from what has also been pre- 
 viously stated in the preceding chapters, I hope 
 it has been satisfactorily shewn that the mind 
 has no direct agency upon the heart ; and still 
 further, that it is of vital importance to cultivate 
 pleasurable and buoyant feelings in our do- 
 niestic or friendly circles ; not for a momentary 
 
AND ANIMAL LIFE. 343 
 
 gratification, but because such are stimuli to that 
 function whose office it is to improve the condition 
 of the blood, and to regulate its distribution, cir- 
 cumstances so important, that every other function, 
 lohether intellectual or organic, operates in extent 
 and correctness, according to the nature and quan- 
 tity of this jiuid. 
 
 CCCCVII. The next class of passions we re- 
 view is that of the depressing. The general ob- 
 servations which I made in speaking of those that 
 excite, concerning the essential qualities of pas- 
 sion, apply with equal force to the present. To 
 illustrate and explain the phenomena of the for- 
 mer, I selected Anger, as presenting extremes in 
 its development, and therefore more likely to be 
 seized by the common observer. To facilitate 
 the accomplishment of the same end, in regard 
 to those that depress, I shall dwell particularly 
 on Fear. 
 
 WHYTT, in treating the subject of passion, re- 
 marks, " The paleness from fear may arise from 
 a different cause, (he had previously spoken of 
 paleness from anger,) viz. a deficiency of the 
 nervous power ; hence, though the small vessels 
 are not affected with any spasm as in anger, yet 
 they are, in a great measure, deprived of their 
 alternate contractions, to which the motion of the 
 blood in them is principally owing." Instead of 
 bringing forward hypotheses of this kind, in sup- 
 port of which we have not the least evidence, I 
 
344 THE LAWS OF ORGANIC 
 
 prefer discussing the merits of general changes 
 in the mode of circulation, as such are apparently 
 more consistent or more easy to demonstrate. 
 
 CCCCVIII. When an individual is acted upon 
 by fear, the first symptoms we perceive, are deep 
 inspirations and paleness. I look upon the lat- 
 ter as invariably the consequence of altered res- 
 piration. The veins of the face have the same 
 dependence upon the action of the respiratory 
 organs as those belonging to the whole surface of 
 the body ; and when the influence of the cause 
 applied to the mind is violent, the general capil- 
 lary system suffers equally ; and when this is mo- 
 derate, the face seems alone to exhibit a sympa- 
 thy, on account of its vicinity to the heart, and being 
 also the seat of expression. The former circum- 
 stance places it more immediately under the con- 
 trol of the disordered function of respiration, and 
 the latter, from the delicacy and sensibility of 
 the part affected, allows us to mark every sudden 
 change. 
 
 CCCCIX. Inspirations, as frequently alluded 
 to, have the tendency to bring the blood towards 
 the chest in greater quantity than usual, and, 
 if we have a superabundance here, it is obvi- 
 ous that a diminution will occur in other situa- 
 tions ; and it is these modifications in its distri- 
 bution that explain the paleness of the face, 
 coldness of the extremities, and the oppression of 
 the chest in fear. It is not intended by this opi- 
 
AND ANIMAL LIFE. 345 
 
 mon to imply that the lungs are the only or- 
 gans in a state of venous congestion, or in a con- 
 dition approaching to it: the abdominal visce- 
 ra will also be implicated in the disorders in- 
 duced. 
 
 CCCCX. It is common for the heart to pal- 
 pitate in fear ; and, whenever this happens, it is 
 not from the mind acting directly upon this or- 
 gan ; nor is it to be referred to any mysterious 
 agency of the brain : but is to be attributed sole- 
 ly to those changes in the mode of respiration 
 which determine within the chest an undue 
 quantity of blood, and which being greater than 
 the heart can with facility propel, destroys the 
 regular order of contraction and dilatation, as de- 
 monstrated by the fluttering or irregular action 
 of the heart. The uneasy sensation will continue 
 as long as the cause remains, and of course will 
 cease in proportion as the sanguineous fluid as- 
 sumes its normal distribution; which improve- 
 ment is easily perceived, from the capillary ves- 
 sels of the face, and other external parts of the 
 body, presenting their usual fulness or colour. 
 
 CCCCXI. The coldness which is experienced 
 is not owing to a condition of the nerves arising 
 immediately from the influence of cold, but ori- 
 ginates from the deranged circulation of blood ; 
 and this feeling is present whenever this state is 
 induced, whether by external or internal means. 
 Intermittent fevers, spasmodic asthma, nauseat^ 
 
346 THE LAWS OF ORGANIC 
 
 ing medicines, and the commencement of most 
 inflammatory diseases, are illustrations of the 
 correctness of the opinion. The same physical 
 alterations may occur without an individual com- 
 plaining of its influence, or apparently being con- 
 scious of its presence, as is frequently observed to 
 be the case when the mind is too much absorb- 
 ed by an interesting tale or discourse, or when 
 the sensorium does not possess its ordinary sen- 
 sibility to take cognizance of those impressions 
 which the nerves transmit. 
 
 A still further illustration, in support of this 
 view, and of the explanation already given of 
 certain phenomena characteristic of fear, is found 
 in retracing the transactions or amusements of 
 our juvenile years. On a winter evening, when 
 assembled together to listen to the credulous 
 matron, who felt all she described, and whose 
 stories, from their interest, suspended every fa- 
 culty except attention, and obliterated every 
 feeling save sympathy the pale countenance, 
 heaving chest, and palpitation of the heart, ex- 
 pressed sufficiently well the depth of our senti- 
 ments, and indicated clearly the cause to which 
 the effects were attributable, viz. the Junctional 
 disorders of respiration. During the continuance 
 of the interest, no shivering or coldness was felt ; 
 but when we approached towards the close, when 
 no further mystery remained to excite or absorb, 
 
AND ANIMAL LIFE. 347 
 
 the mind became susceptible of the sensation of 
 cold. 
 
 CCCCXII. Persons have frequently died from 
 the effects of anger and fear; but the proximate 
 cause of death in these two passions is as opposite 
 as the feelings by which they are accompanied. In 
 the former, from the expirations being long conti- 
 nued and violent, the return of the blood from the 
 head is impeded, and apoplexy is the consequence; 
 but, in the latter, the head and the surface of the 
 body have less, and the lungs more, of this vital 
 fluid, than in the natural state of the system. The 
 surcharge of the lungs explains the difficulty to 
 which the heart is opposed in circulating the 
 blood, and, when the accumulation is great, ac- 
 counts also satisfactorily for the complete cess- 
 ation of the action of this organ. 
 
 CCCCXIII. It might probably be expected 
 that we should here treat the subject of Melan- 
 choly, as being of a depressing nature ; but as 
 this belongs to the character of the tempera- 
 ment, and is rather continuous than temporary 
 in its results, it is evidently excluded from the 
 definition I have given of passion. Cheerfulness 
 has the same relation to the previous class we 
 have considered, that melancholy has to that of 
 the depressing; and it is from the same reasons 
 that it was not mentioned when I glanced at 
 some of the peculiarities of exciting passions. 
 
348 THE LAWS OF ORGANIC 
 
 CCCCXIV. Wonder, as it produces instanta- 
 neous consequences, and these of an obvious de- 
 scription, is with propriety regarded as a passion. 
 When something is suddenly presented to the 
 mind which is new and strange, it creates a series 
 of emotions from the perplexities and doubts ap- 
 pertaining to the object; and the influence of this 
 is perceived in the pale or vacant expression 
 of the countenance, in the palpitation of the 
 heart, or in the disagreeable sensation of the pree- 
 cordial region. These effects vary little from 
 those characteristic of fear ; and if we minutely 
 observe the manner in which respiration is per- 
 formed on the present occasion, we shall conclude 
 that the same general derangement of this im- 
 portant function is the sole cause of the different 
 phenomena belonging to both. 
 
 CCCCXV. Grief, although the consequence 
 of an immediate impression of an unpleasant 
 kind, and although it is easily traced to its source, 
 from its direct and evident connexion with ante- 
 cedent circumstances, yet differs widely from 
 almost every other passion. It originates in the 
 same manner, but instead of disappearing after a 
 few minutes, which is frequently the case with 
 the preceding, it continues at times for days, 
 weeks, and months, and during the whole of this 
 period we have more or less some of those exter- 
 nal signs which depict the passion and charac- 
 terize the nature of its primary development. 
 
AND ANIMAL LIFE. 349 
 
 We are almost entitled to call this state of the 
 mind at one time an acute and at another a chro- 
 nic affection ; for in those instances in which it 
 does not subside, like the generality of our violent 
 feelings,it presents throughout its duration symp- 
 toms so well marked as almost to authorize the 
 employment of a term which supposes the ab- 
 sence of those indications by which it was in the 
 first place particularly distinguished, and yet, at 
 the same time, a state of aberration too evident 
 to be neglected or unobserved. 
 
 CCCCXVI. It is impossible to bring forward 
 any passion that more clearly shows the validity 
 of the principles proposed than that of grief. The 
 constant sighing, or deep inspirations, must neces- 
 sarily tend to pervert the proper distribution of 
 the blood throughout the system ; and must also 
 facilitate the accumulation of the same in the 
 lungs. I shall not multiply any further observa- 
 tions on this passion, nor do I think it necessary 
 to examine the phenomena of any other, as they 
 are all referrible to those states that either excite 
 or depress ; and although they may otherwise 
 seem to differ, yet the diversities, when investi- 
 gated, will be found to consist rather in the degree 
 than in the nature of the feeling, understanding 
 by nature the qualities distinctive of each class, 
 and not the fine and ingenious divisions of the 
 metaphysician. 
 
350 THE LAWS OF ORGANIC 
 
 SECT. III. The Influence and Effects of Passion. 
 
 CCCCXVII. In all ages the mind has been 
 supposed to operate in a mysterious and ex- 
 tensive manner upon the body, not only in 
 the state of health producing acute affections, 
 but also increasing the susceptibility of the con- 
 stitution to every variety of disease ; and the 
 same power has also been equally efficient in re- 
 tarding or arresting the progress of general and 
 local maladies. I shall not occupy the reader's 
 attention by an enumeration of facts in support 
 of the opinion, for these possess not only uni- 
 versal belief, but individual corroboration, but 
 shall proceed to develope the principles, which 
 are alone sufficient to explain the nature of the 
 connection and the character of the results. 
 
 CCCCXVIII. Exciting passions are consider- 
 ably less dangerous than the depressing to the 
 well-being of the constitution. The former sel- 
 dom excite or predispose to any disease, except 
 active aneurism of the heart, apoplexy, or 
 congestion of the brain ; they very rarely pre- 
 dispose to disorders of the lungs, or tedious ner- 
 vous affections, nor do they enfeeble the diges- 
 tive functions, nor increase the liability to con- 
 tagion, all of which effects are found to follow 
 depressing states of the mind. 
 
 CCCCXIX. The strong and vigorous consti- 
 tution is almost proof against contagious and 
 
AND ANIMAL LIFE. 351 
 
 epidemic diseases, if it have not, for a short time 
 previous to exposure, been deranged by excess 
 of some kind. -The reason of this will pro- 
 bably be understood from the following con- 
 siderations. The blood is the only general sti- 
 mulus of the body, and the different organs 
 will be excited or depressed according to the 
 properties of this fluid. Whether the agent 
 which produces fever be effluvia from the body, 
 or an impure condition of the atmosphere, it is 
 always to be regarded as a sedative, and its in- 
 fluence is to diminish the powers of life. When 
 an individual possesses superior physical endow- 
 ments of the system, he is less prone to conta- 
 gious diseases, because the natural stimulus of the 
 blood is sufficient to counteract the evil pro- 
 perties of that to which it is exposed. It is on 
 this account that persons who are kept in a con- 
 stant state of excitation from spiritous liquors, 
 can frequently mingle with impunity among 
 those infected with contagious disease ; and it is 
 also from the same cause that fever has in many 
 instances been cut short. 
 
 CCCCXX. When I remark that the strong 
 and vigorous are often exempt from contagion, 
 it is necessary to limit the observation, or to 
 state those circumstances which seem on the one 
 hand to support, and on the other to invalidate 
 the opinion. When individuals from the country, 
 possessed of sound constitutional qualifications, 
 are brought within the influence of contagion, 
 
352 THE LAWS OF ORGANIC 
 
 they are more frequently attacked than others 
 similarly constituted, in the same situations. In 
 agricultural pursuits there are pure air and exer- 
 cise ; but when those who follow such pursuits re- 
 side in, or visit a town, for a period, however 
 short, where fever is raging, they not unusually 
 become affected. We must, in the first place, 
 suppose a specific poison to exist in the atmos- 
 phere to which the patient is confined, and to 
 which every person is equally exposed that 
 approaches its limits ; but, besides this, there is 
 an unhealthy condition of the air which is 
 breathed, arising from its deficient circulation 
 and from want of cleanliness, to which one 
 unaccustomed to such impurities is more par- 
 ticularly sensible. This state of the atmos- 
 phere acts conjointly with the contagious mat- 
 ter; but that is particularly felt by him only 
 who is a stranger to its qualities, and, therefore, 
 it is obvious that he has to contend against this 
 condition of the atmosphere, and also against the 
 common specific principle of the disease* 
 
 CCCCXXI. Professional characters, for the 
 purpose of investigating truth, or relieving the 
 sick, have occasionally devoted their days and 
 nights to attendance on those suffering under the 
 most severe forms of the plague, without falling 
 a sacrifice to its ravages. To him who is fully 
 acquainted with history, it is superfluous to men- 
 tion many remarkable instances connected with 
 
 * Vide Appendix. 
 
AND ANIMAL LIFE. 353 
 
 the influence of the mind on the body. Ar- 
 mies, when flushed with victory, have been able 
 to traverse the most unwholesome situations 
 without detriment to health ; and such a feel- 
 ing has often dissipated malignant fevers and 
 affections, which were previously thinning their 
 ranks. PETIT, of Lyons, relates, that during 
 the time this city was besieged, in 1793, every 
 common sore was almost immediately affected 
 with gangrene, and that this consequence was 
 not only observed here, but showed itself in 
 every other place subject to the same unfortur 
 nate circumstances. 
 
 CCCCXXII. In explaining these phenome- 
 na, I am forced to recur to certain principles de^ 
 veloped at the commencement of this work, viz. 
 that the blood is oxygenated, consequently stimulat- 
 ing, in the inverse ratio of the quantity contained 
 within the chest. Depressing passions have one 
 universal tendency, to augment the proportion 
 which the lungs receive, and therefore to dete- 
 riorate the condition of the sanguineous fluid. This 
 alteration is not produced in a moment, so as to 
 be sensibly felt by the whole body ; it is impos- 
 sible to fix any precise period for its occurrence, 
 as it is regulated entirely by the susceptibility 
 of the mind, and the severity of the depressing 
 feeling. If we suppose an individual to be con- 
 tinually apprehensive of losing his life, property, 
 or friends, he will sigh, or draw cjeep inspira- 
 
354 THE LAWS OF ORGANIC 
 
 tions when reflecting on the probabilities of for- 
 tune, and, when not particularly engaged on this 
 subject, his respiratory functions will still show 
 that they are governed occasionally by the im- 
 pressions of the same cause. 
 
 CCCCXXIII. Digestion, secretion, circula- 
 tion, in fine, every animal and organic function, 
 are deranged by the deteriorated qualities of 
 the blood : Whenever this wants its usual sti- 
 mulus, the constitution will be predisposed to fever ; 
 and if the solids of the body have been for some time 
 supplied with vitiated fluids, those will, on the slight- 
 est occasion, exhibit symptoms of mortification. 
 
 CCCCXXIV. The above consequences are il- 
 lustrations of an extreme condition of the body ; 
 but if we examine the results of milder causes, 
 we shall observe effects in harmony with the 
 same. If the passion of grief be felt for a few 
 weeks or months, the eye soon loses its bright- 
 ness, and the countenance its natural expression 
 and colour ; digestion is tardy and fastidious ; 
 secretion is generally disordered ; the circulation 
 is quick and feeble, its distribution is rather in- 
 ternal than external, and the temperature of the 
 body is diminished : but as soon as the mourn- 
 ful object ceases to control the operations of the 
 mind, so soon does this restore to the respiration 
 its normal action, and every part of the system 
 is invigorated with new life. 
 
 CCCCXXV. Depressing passions being at 
 
AND ANIMAL LIFE. 355 
 
 all times injurious, Providence has so constituted 
 our minds, and the world without us, that it is 
 almost impossible to dwell long on what is dis- 
 agreeable to our feelings. The variety of our 
 intellectual faculties, sentiments, and passions, 
 is with difficulty concentrated to one point: 
 each having its own individual object, will, as it 
 were, unconsciously steal from the absorbing 
 subject, and apply itself to that which has a 
 much closer relation to its taste ; and Na- 
 ture, whether endowed with animal or vegeta- 
 tive life, or whether subject to inorganic laws, 
 teems with those diversities that are well fitted 
 to elevate or expand the mind, or, with eloquence 
 peculiar to herself, will teach us either to over- 
 look or to improve the present. 
 
 CCCCXXVI. In those cases in which the 
 mind continues to brood upon its sorrows till 
 the body is too much emaciated to recover its 
 wonted energy, the explanation of the pheno- 
 mena will be found in the principles developed 
 in different parts of this work. To break the 
 chain of unpleasant associations, the first step is 
 to remove the individual from the situation 
 with which these are connected ; or, by lively 
 society and cheerful amusements, to present new 
 objects for thought : or, if he complain of ima- 
 ginary or slight derangements of the system, to 
 prescribe rather to satisfy his fancy than to cure 
 supposed diseases. The mere exhibition of me* 
 
356 THE LAWS OF ORGANIC 
 
 dicines forms but a slender part of the profes- 
 sional duties of a physician ; and it is to be 
 regretted that his value, in the eyes of a great 
 part of mankind, is estimated by his obvi- 
 ous operations, and not by the obvious bene- 
 ficial results. There was a time when charms 
 and specifics were held in high repute ; and, 
 although we are at present too enlightened to 
 allow the public to be indiscriminately imposed 
 on, yet I hope we are sufficiently candid to ac- 
 knowledge that these have not only protected 
 thousands from disease, but have saved them 
 when scientific practice had lost its efficacy. 
 Although we are unwilling to imitate servilely 
 the product of ignorance, let us appreciate and 
 apply those principles from which empiricism 
 and priestcraft have derived the greater part of 
 their reputation and consequent success. 
 
 CCCCXXVII. Individuals who have suffer- 
 ed long from depressing passions are frequently 
 subject to pulmonary affections. If we consider 
 that the lungs, throughout the mental disturb- 
 ance, have been more or less oppressed by the 
 congestion of blood, and this of a quality not 
 calculated to stimulate the thoracic and abdomi- 
 nal organs, the occurrence of disorganization 
 ought not to surprise. 
 
 CCCCXXV1IL BICHAT, in his General Ana- 
 tomy, relates one or two interesting cases of in- 
 dividuals who had suddenly become jaundiced 
 
AND ANIMAL LIFE. 357 
 
 from the influence of fear ; and others of a simi- 
 lar kind are mentioned by GEORGET, in his Phy- 
 siology of the Nervous System ; indeed, exam- 
 ples of this description are by no means rare. 
 BICHAT, in reasoning upon the origin of the 
 symptoms, endeavours to show, that fear has an 
 intimate connexion with the liver, agreeably 
 to his notions concerning the seat of passions. 
 He states, that the secretion of bile is increased, 
 as proved by the surface becoming of a yellow 
 colour. The change in the aspect of the body 
 appears to be the only fact from which he 
 deduces his opinion : and as this condition 
 occurs in many instances where such a supposi- 
 tion cannot be allowed, we cannot permit it to 
 pass without examination. Jaundice is common 
 in chronic diseases of the liver, in the obstruc- 
 tion of the biliary ducts by stones, or from any 
 other cause producing the same physical effect. 
 It is often found to take place at the commence- 
 ment of certain fevers ; and its derangement is 
 evident in many acute and chronic affections of 
 the abdomen : the secretion of bile appears oc- 
 casionally so much increased, as to characterize 
 particularly one fever. 
 
 CCCCXXIX. Whenever the bile is not allow- 
 ed to take its natural course, it is absorbed and 
 carried along by the circulation through every 
 part of the system, as when the passage is ob- 
 structed by biliary stones or other causes, or by 
 
358 THE LAWS OF ORGANIC 
 
 tumours in the vicinity of the ducts compressing 
 the parietes of those through which the bile flows. 
 
 In chronic diseases of the liver, this organ is 
 enlarged and congested. In disorders of the ab- 
 domen, attended by fever, it is undoubted, that 
 the viscera are generally in a state of congestion ; 
 the augmented size of the liver is evident to the 
 hand : depressing passions have the tendency to 
 induce the same conditions. Observing that the 
 influence of fear is to engorge this organ, and, 
 whenever this is the case, that the surface of the 
 body loses its natural colour, I am disposed to 
 infer, that the congestion of the tissue does not 
 promote an increased secretion of bile, but pre- 
 vents its transmission to its ordinary receptacle, 
 thereby placing the bile under circumstances dif- 
 fering little from those in which itsjlow is arrest- 
 ed, either partially or generally, by foreign bodies or 
 organic alterations. 
 
 In corroboration of this view, it may be re- 
 marked, that our treatment in such cases is cal- 
 culated to disburthen the overloaded vessels 
 of the liver ; and in proportion to the success of 
 these means is the disappearance of the peculiar 
 symptoms of jaundice. 
 
 CCCCXXX. Diarrhoea is commonly an at- 
 tendant on fear ; and, as this disease is more fre- 
 quently the consequence of disordered secretion 
 than an augmentation of a natural action, I at- 
 tribute it in this instance to the presence of 
 
AND ANIMAL LIFE. 359 
 
 deteriorated blood, conjoined with a surcharge of 
 the organs appropriated to secretion. I cannot 
 possibly explain how this quantity or quality 
 of blood acts, nor shall I attempt a solution of 
 the difficulty : At present it is sufficient to 
 show that diarrhoea very often occurs when the 
 sanguineous fluid is determined to the abdomin- 
 al viscera by the depressing influence of fear ; 
 or, at the commencement of dysentery, the ori- 
 gin of which I have endeavoured to trace in the 
 chapter on the action of Emetics : and as the 
 present investigation includes the same consi- 
 derations, the reader is referred to that part of 
 the work for a fuller statement of the views. 
 
 By these observations it is by no means intend- 
 ed to show that diarrhoea at all times depends 
 on one state of the system, as, for example, the 
 one described ; the different conditions of the 
 body that predispose to this effect are numer- 
 ous, and of very opposite kinds, the elucidation 
 of which does not belong to the subject of pas- 
 sion. 
 
 CCCCXXXI. There is another prominent 
 consequence connected with fear, the study of 
 which is equally important as the preceding, and 
 the views brought forward to explain its ori- 
 gin will probably throw considerable light on 
 other phenomena of the system which appear to 
 have no relation to the present subject I al- 
 lude to the flow of limpid urine.* 
 
360 THE LAWS OF ORGANIC 
 
 This extraordinary symptom would seem to 
 depend on the same condition of the blood and its 
 distribution that we stated to exist in diarrhoea. 
 In hysteria, nervous diseases, spasmodic asth- 
 ma,* and in several febrile affections, the urine is 
 much changed either in its general colour or quan- 
 tity, or in both. The ancients, who attended much 
 to critical days, considered a favourable crisis at 
 hand when the urine in fever deposited a sedi- 
 ment, or lost its usual watery appearance. The 
 moderns, who observe, are disposed to regard 
 this occurrence in the same light. Why the ab- 
 sence or presence of this simple sign should 
 be believed untoward or propitious has never 
 been explained. Fever never exists without dis- 
 turbing the whole frame : when ushered in, it 
 generally excites the organic and animal func- 
 tions, and as long as this action continues the 
 urine is neither particularly copious nor limpid, 
 often in the opposite states : but when the symp- 
 toms are changed, and we perceive them to be 
 of an asthenic character, or in any measure ap- 
 proaching to it, the urine is then pale, showing 
 that the blood Jrom which it is formed is deficient 
 in its usual properties. 
 
 CCCCXXXII. When the internal organs are 
 gradually relieved of the increased quantity and 
 improper quality of the blood, they allow this to 
 
 * It has previously been shown that the symptoms which 
 characterise these diseases indicate internal congestion. 
 
AND ANIMAL LIFE. 361 
 
 circulate through them with greater facility ; and 
 being of a kind adapted to stimulate the various 
 functions, the change in the secretion of the 
 urine is the result of this general improvement. I 
 have before stated that whenever the circulation 
 is equalized the blood is always better oxygenat- 
 ed; and this opinion receives additional strength 
 in the examination of these phenomena. 
 
 CCCCXXXIII. When digestion is imperfect, 
 we have very frequently a disturbed or muddy 
 state of the urine ; and, during the continuance 
 of fever, this and most of the abdominal func- 
 tions are disordered to a greater extent. The 
 presence of the deposition may, in all cases, save 
 those in which we have disease of the kidneys 
 or bladder, be considered to indicate derange* 
 ment of the stomach or chylopoietic organs. Fever 
 itself is not an exception" to this opinion. The 
 copious deposition in the latter stage of fever 
 shows, that the blood and its circulation are improv- 
 ed ; the different kinds of imperfectly assimilated 
 matter are taken up by the invigorated action of 
 the absorbents ; and, as the urine is derived from 
 the blood, its alterations may be regarded as the 
 result of a better condition and more regular distri- 
 bution of the vital fluid. 
 
 CCCCXXX1V. Fear has at times instan- 
 taneously sobered individuals highly intoxicated 
 and furious. I am acquainted with one remark- 
 able instance of this kind. A gentleman had 
 partaken too freely of the bottle, and was alto- 
 
362 THE LAWS OF ORGANIC 
 
 gether ungovernable, and, while exercising a few 
 of his combative qualities, he suddenly recollect- 
 ed that he had a considerable sum of money up- 
 on him : he instinctively placed his hand where 
 he supposed it to be, and, to his astonishment, 
 found it missing. This unpleasant discovery im- 
 mediately produced a death-like paleness of the 
 face, and he became as quiet and collected as one 
 that had taken no spirits. After making in- 
 quiry concerning it, he learnt that his brother 
 had taken it from him for the purpose of secur- 
 ing it : being assured of the truth of this, he 
 immediately became as intoxicated and ungo- 
 vernable as before. 
 
 Fear, as I have before stated, diminishes the 
 quantity, and probably the action, of blood in the 
 superior and inferior extremities, and on the 
 surface of the body. This change was suddenly 
 induced in the above example, by the supposed 
 loss of the money ; and as soon as the alarm was 
 found to be false, so soon did the respiratory 
 function resume its previous action, and re- 
 establish the abnormal circulation of the brain. 
 
AND ANIMAL LIFE. 363 
 
 CHAP. XVI. 
 
 An Inquiry into the Nature of the Vital 
 Principle. 
 
 SECT. I. An Investigation of the different Phenomena 
 attributed to an Unknown or Immaterial Principle. 
 
 CCCCXXXV. IN undertaking the present 
 subject, I am not insensible that I tread upon 
 ground deemed sacred by the vulgar and the 
 greater part of the enlightened of mankind. 
 The prejudices of youth and of education, and the 
 various associations connected with what is 
 great or wonderful in Nature, tend to retard ma- 
 terially our knowledge of phenomena which are 
 properly within the comprehension of our facul- 
 ties. The child regards, with infinite, pleasure, the 
 different motions of the automaton, or the vari- 
 ous actions of the puppet, without being able to 
 consider the cause of its admiration ; and the 
 mind of man is also liable to be unduly excited, 
 or improperly directed, in observing the phe- 
 nomena of animal and vegetable nature, as these 
 differ so widely from every effect characteristic 
 of inert matter. 
 
364 THE LAWS OF ORGANIC 
 
 CCCCXXXVI. Some have supposed life to 
 be synonymous with soul, and, therefore, assert 
 that it is an immaterial principle, altogether be- 
 yond the province of intellectual pursuits ; but 
 others, with apparently more correctness, are 
 inclined to regard life as produced and regulat- 
 ed by the laws which the Deity has impres- 
 sed on the particles of matter. The individual 
 who entertains the latter opinion has senti- 
 ments as pure and elevated as he who refers 
 every act of existence to the direct agency 
 of Providence ; nor does the doctrine tend to 
 lessen his admiration of what is everywhere 
 great and good throughout nature, nor does it 
 in the least tend to diminish his reverence and 
 the grateful feelings of his heart towards the 
 great Author of his being. Of the two opinions, 
 that which is deemed material is better calculat- 
 ed to excite wonder and religious awe in one 
 highly gifted, as it presents to the expanded 
 faculties of the mind the infinite laws of his crea- 
 tion, whereas, when these are referred to the 
 direct agency of Providence, they cannot be con- 
 sidered as a source of wonder, but may of ado- 
 ration, as the Spirit of the Most High is all 
 sufficient. 
 
 CCCCXXXVII. If the general properties 
 of life be allowed to be sufficient to demonstrate 
 an immaterial principle or soul, every link of 
 animal and vegetable nature will be granted 
 
AND ANIMAL LIFE. 365 
 
 to possess it ; and it still further must be admit- 
 ted, that this principle is subject to decay and 
 reproduction, to derangement or disease, as its 
 manifestations are deranged or diseased by a va- 
 riety of causes. The soul and its ultimate des- 
 tination are objects for the study of the ethical 
 philosopher ; but their development and foun- 
 dation cannot be traced and proved by the 
 bounded powers of the mind, it is to Revela- 
 tion alone that we must appeal for a knowledge 
 of these great truths. 
 
 CCCCXXXVIII. In examining the qualities 
 of matter completely destitute of the principle 
 of life, we have much to admire. Certain par- 
 ticles combine, and the product is unlike the 
 previous properties of either ; poisons become 
 harmless or beneficial by the addition of a new 
 principle, or different proportions of the same 
 of which they are composed ; salts and crystals 
 have their determinate forms, and it scarcely can 
 be considered less strange, that such substances 
 should exhibit a definite external character, than 
 that arteries and veins should be developed with 
 the same unerring certainty in the animal sys^ 
 tern. 
 
 CCCCXXXIX. It is as difficult to show in 
 what manner, or by what exact laws, crystals have 
 an invariable tendency to assume the varieties 
 of determinate forms, as to explain in what way 
 an artery or vein is organized. The former phe- 
 
366 THE LAWS OF ORGANIC 
 
 nomena appear as wonderful as the latter. Both 
 objects are material, but composed of different 
 principles ; but whether the difference consist in 
 the simple or compound nature of these, I shall 
 not presume to say. 
 
 CCCCXL. Why the particles of inert mat- 
 ter are attracted to each other, and form a nu- 
 cleus, is unknown ; and we are equally ignorant 
 of the cause that induces particles derived from 
 animal or vegetable matter to combine in order 
 to develope the various parts of either of these 
 great systems of nature. Blood-vessels are ob- 
 served in the foetal germ, before any other or- 
 ganized structure, and, when these are but par- 
 tially formed, they are prepared to promote still 
 further the objects which nature has in view, as 
 they convey and distribute the maternal blood, 
 which is the exclusive source of every subsequent 
 development. As these vessels become more 
 manifest, the progress of organization proceeds, 
 not precisely as an effect of the first exciting 
 impulse, but as an immediate consequence of the 
 progressive evolution of additional structures, 
 and of the more copious supply of maternal 
 blood ; and these causes augment and continue 
 to operate, till the different organs are constitut- 
 ed, which are necessary to maintain an indepen- 
 dent organic and animal life. 
 
 CCCCXLI. It is extremely difficult to de- 
 fine life. If it be supposed to have any indis- 
 
AND ANIMAL LIFE. 367 
 
 pensable relation to the faculties of the mind, to 
 the sensibility of the frame, or the senses with 
 which an individual is endowed, we have vege- 
 tation, on the one hand, presenting occasionally 
 the exuberance of life, and, on the other, we 
 have animals almost completely destitute of the 
 above conditions ; even man himself exhibits 
 different degrees of perfection in the instruments 
 by which he acquires his knowledge and elevates 
 his natural pre-eminence. We have every ap- 
 pearance of life, where we have neither voluntary 
 motion, sensibility, intellect, nor any of the five 
 senses, and yet we observe that these striking 
 characteristics of life, and the different organic 
 functions, bear a direct ratio to the development 
 and perfection of those organs on which these 
 endowments depend. From such facts, we may 
 infer that life is extended or contracted accord- 
 ing to the number or magnitude of the various 
 organs of the system ; and, still further, that it 
 possesses its degrees in the same individual at 
 different periods of existence, or in different 
 states of the constitution. The youth, buoyant 
 with high spirits, ambitious from the vigour of 
 his mind, and restless from the energy of his 
 animal and organic functions, must be allowed 
 to possess a greater share of the principle of life 
 than the aged and emaciated being, almost para- 
 lysed by debility, imbecile in mind, from his im- 
 
368 THE LAWS OF ORGANIC 
 
 poverished or ill-conditioned brain, indifferent 
 to the pleasures of society, the joys of sense, and 
 almost every tie that binds the soul to earth. 
 
 CCCCXLII. Dead animal or vegetable sub- 
 stances cannot in the least be likened to brute or 
 inert matter. The former contain the remains 
 of those principles that were deemed vital in 
 their operation and effects, viz. the circulating 
 fluids, which are proper to every part of the organ- 
 ized system. As these principles, a few seconds 
 before death, were capable of maintaining the 
 various functions of the living economy, it can 
 scarcely be denied that immediately after this 
 event the properties of the fluids are unchanged. 
 This argument is, in some measure, illustrated 
 in the recovery of individuals from drowning, in 
 transfusion, or certain accidents. Dead animal 
 or vegetable substances, although inorganic, are 
 not destitute of those material principles which 
 supported the complex functions of animal or 
 vegetable life ; and these, therefore, when free 
 from organic laws, quickly undergo what is 
 called decomposition, which is owing to the 
 formation of other combinations, and, in conse- 
 quence of these changes, life appears again under 
 a variety of aspects. 
 
 CCCCXLII1. The various organs of the body 
 possess different degrees of vitality in proportion 
 to the quantity of the circulating fluid they re- 
 ceive ; and may also be considered vital accord- 
 
AND ANIMAL LIFE. 369 
 
 ing as they contribute to the support of the 
 whole system. The lungs, the heart, and the 
 blood-vessels exhibit these two conditions to 
 a greater extent than any other of the constitu- 
 tion. 
 
 CCCCXLIV. Physiologists are continually di- 
 lating on the wonderful properties of the vital 
 principle, in resisting great heat or cold ; in ex- 
 erting itself, on extraordinary occasions, as if en- 
 dowed with consciousness, or fully aware of the 
 necessities which are present. But these indivi- 
 duals do not state, nor even endeavour to ex- 
 plain its nature, while they at the same time en- 
 tirely neglect to consider the physical conditions 
 of the system, whose changes will be found, from 
 the following observations, amply sufficient to 
 solve many of the seeming difficulties connected 
 with the subject. 
 
 CCCCXLV. Many experiments were per- 
 formed by HUNTER which tended, according to 
 his reasoning, to prove, that the phenomena he 
 observed were to be attributed to a vital prin- 
 ciple, exempt from the conditions of matter ; and 
 the same experiments are brought forward by 
 other writers to enforce the same opinion. 
 
 A dead penis, and one of a living person, both 
 of the temperature 92, were immersed in the 
 same vessel with water at 50.* He remarked, 
 
 * Observations on certain parts of the Animal Economy. 
 By JOHN HUNTER, p. 108. 
 
 A a 
 
370 THE LAWS OF ORGANIC 
 
 \ 
 
 " that the dead cooled sooner by two or three 
 minutes ; the living sunk the quicksilver to 58, 
 and the dead to 50." There is nothing extra- 
 ordinary in this result, but, on the contrary, it 
 is such as we should naturally expect. The 
 dead penis is to be considered as an inorganic 
 substance, deriving its heat entirely from the 
 medium in which it had previously been placed, 
 whereas the living one has its temperature con- 
 tinually renewed by the circulation of fresh portions 
 of Hood. The portion which is this moment 
 cooled is necessarily transmitted by the veins to 
 the heart, and arterial blood of the temperature 
 of the body flows hither, and this again is cool- 
 ed, and these series of interchanges unceasingly 
 operate with different degrees of facility and 
 perfection. When the living penis has been im- 
 mersed for some time in water as low as 50, the 
 blood-vessels are constricted, preventing the 
 transmission of the usual quantity of sanguine- 
 ous fluid, and as that which is acted upon re- 
 turns with difficulty, the living penis has its 
 temperature very much reduced. The dead 
 penis, deprived of the physical conditions of the 
 living, has its temperature speedily diminished, 
 and necessarily to a greater extent than the 
 other. 
 
 CCCCXLVI. In the next experiment, the 
 living penis, having the temperature of 92, was 
 immersed for two minutes in water, heated to 
 
AND ANIMAL LIFE. 371 
 
 113. The heat of the parts was raised to 
 but could not be raised higher.* In another 
 experiment " the living and dead parts were 
 both immersed in water, gradually made warmer 
 and warmer, from 100 to 118, and continu- 
 ed in that heat for some minutes ; the dead 
 parts raised the thermometer to 114, while the 
 living raised it no higher than 102?. 
 
 When the living parts were immersed in wa- 
 ter fourteen or fifteen degrees above the temper- 
 ature of the system, the heat which they, or more 
 correctly the blood, acquired, was quickly car- 
 ried into the system by the veins. The arterial 
 fluid subjected to this warm medium continual- 
 ly acquires additional heat, but this is imme- 
 diately transmitted by the veins ; and it is on 
 this account, and not from the existence of a pecu- 
 liar vital principle, that the living parts cannot be 
 heated beyond a few degrees. 
 
 When cold was employed in the first experi- 
 ment the capillaries of the penis were powerful- 
 ly affected, because the return and transmission of 
 the blood were impeded ; but, in the present case, 
 the warm water facilitates both the return and 
 transmission of the blood, and therefore tends to pre- 
 serve the living parts from an inordinate rise of 
 temperature. There is a circumstance connected 
 with the present experiment, which beautifully 
 
 * Ibid. p. 109. t Ibid. p. 110, 
 
 A a 2 
 
372 THE LAWS OF ORGANIC 
 
 illustrates the correctness of the explanation I 
 have given. When the thermometer was put 
 close to the living penis, after it had been im- 
 mersed for some minutes in the warm water, 
 " the quicksilver immediately fell from 118 to 
 104, while it did not fall more than a degree 
 put close to the dead."* 
 
 The individual who submitted to this experi- 
 ment did not feel the water unpleasantly warm 
 when the parts had been immersed in it for a 
 few minutes ; but whenever the water was agi- 
 tated it was felt disagreeably hot. It is manifest 
 that the circidation of blood through the penis 
 continually robbed the water in contact with it 
 of a portion of its heat. As the blood was warm- 
 ed at the expense of the surrounding medium, 
 and as it was renewed every few seconds, the 
 water would necessarily lose several degrees of 
 heat. When the water was agitated, another 
 portion, which had not been particularly acted 
 upon by the blood, was then placed in contact 
 with the living parts, which satisfactorily ac- 
 counts for the heat which was experienced from 
 this simple circumstance. 
 
 CCCCXLVII. RICHERAND, the distinguish- 
 ed French physiologist, has endeavoured to sup- 
 port views similar to those of HUNTER. He 
 says, " I applied bags filled with very hot sand, 
 along the leg and foot of a man whose artery 
 
 * Ibid, P . no. 
 
AND ANIMAL LIFE. 373 
 
 had been tied by two ligatures in the hollow of the 
 ham, for popliteal aneurism. Not only the limb 
 was not chilled, which is what happens when the 
 course of the blood is intercepted, but the extrem- 
 ity, thus covered, acquired a heat much above the 
 ordinary temperature of the body. The same 
 apparatus, applied to the sound leg, did not pro- 
 duce this excess of heat, certainly* because the ful- 
 ness of life in that limb resisted the physical action"* 
 The explanation of this phenomenon is as 
 simple and satisfactory as the preceding in re- 
 ference to the experiments of HUNTER. An 
 artery had been tied in the leg, which would pre- 
 vent the limb from receiving its ordinary quanti- 
 ty of blood, and, consequently, the extremity 
 would become less- vascular, and the circulation 
 would likewise be irregular. On the application 
 of the sand bags, the sanguineous fluid would 
 be warmed, but the limb not possessing the usual 
 quantity, would, therefore, be in cap able of carrying 
 off the external heat to the same extent, and with 
 the same facility, as the greater quantity of blood 
 and its more regular circulation in the sound limb. 
 The extremity in which the arteries were tied, 
 from the great diminution which it suffers in 
 the proportion of the circulating fluid usually 
 
 * Elements of Physiology, p. 45. Edit, quarto. Translated 
 by G. J. M. DeLus, M. D ; with Notes and a copious Appen- 
 dix by JAMES COPLAND, M, D. 
 
374* THE LAWS OF ORGANIC 
 
 distributed to it, may be considered as approach- 
 ing to inorganic matter, and the effects which it 
 exhibits approximate in character to those ob- 
 served in substances altogether destitute of life 
 when subjected to the same circumstances. 
 
 CCCCXLVIII. It is not unusual to observe 
 good, and almost immediate effects, to succeed 
 the amputation of a limb. Paleness, emaciation, 
 debility, and irregularity of the various organic 
 functions, are removed or lessened by such an 
 operation, and these beneficial results are prin- 
 cipally to be attributed to two causes, viz. relief 
 from mental perturbation, and a more copious sup- 
 ply of blood to the remaining parts of the system. 
 On the first point it is unnecessary to insist, as 
 the influence of the mind on the corporeal func- 
 tions is too well known to require further com- 
 ment. Previous to the amputation of a limb, the 
 chief artery or arteries are compressed, which cir- 
 cumstance prevents the ordinary distribution of the 
 vital fluid to the parts which are to be removed, 
 so that the amputated extremity contains much 
 less blood than is possessed by that which is 
 sound : it is therefore evident that the system has 
 received an increase ; and this quantity, although 
 small, may be considered in the light of a natu- 
 ral transfusion, and tends, like that which is oc- 
 casionally employed in cases of great loss of 
 blood, to revive the sinking powers of life. 
 
AND ANIMAL LIFE. 375 
 
 In proof of the great increase of sanguineous 
 fluid to the system, I may observe that thora- 
 cic inflammations sometimes succeed the oper- 
 ation, or great irregularity in the functions 
 of those organs necessary to oxygenate and 
 circulate the blood, and the different symptoms 
 are generally relieved by depletion. I have al- 
 ready remarked, in the chapter on Torpidity, 
 CLXXXVI,that, by circumscribing the circle of 
 circulation, we enable the heart to act with 
 greater ease; but, in the instances which I 
 brought forward, we had a diminished quantity 
 of blood in motion ; but when we lessen the cir- 
 cle by the removal of a limb d we throw more 
 blood of a stimulating kind upon the internal 
 cavities, thereby exciting the heart to augmented 
 contractions^ the energy of whose effects are im- 
 mediately transmitted to the lungs and the whole 
 vascular system. These conditions act and re- 
 act, improving digestion and assimilation, in fine, 
 bestowing new life on the impoverished func- 
 tions of the body. In such instances it cannot 
 be denied that the relation between the cause 
 and effect is obvious, and the conclusion which 
 naturally flows from such premises is, that the 
 principle of life was weak or diminished when the 
 system was deprived of the necessary quantity or 
 quality of blood, and that this principle became 
 strong or increased when one or both of these pro- 
 
376 THE LAWS OF ORGANIC 
 
 perties were present. I shall attempt, in the fol- 
 lowing pages, to show in what way the quality 
 of the blood is improved, and also what is the 
 agent ; w r e shall then be still better able to judge 
 of the principle of life. These observations 
 suggest to the surgical operator the necessity of 
 preserving, as much as possible, the vital fluid 
 for the benefit of the system, when such is im- 
 peratively demanded. This object is accom- 
 plished by applying the tourniquet, or similar 
 means, to the trunks of the principal arteries 
 belonging to the limb, for a few minutes previ- 
 ous to the operation. When the extremity is 
 thus circumstanced, the arterial blood is neces- 
 sarily very much impeded in its flow to the 
 limb, if not almost suppressed, while, at the same 
 time, the venous does not experience an equal 
 difficulty in its return. 
 
 CCCCXLIX. The observations and precepts of 
 mankind, in general, are frequently more valu- 
 able than the man of science is disposed to allow. 
 The basis of the greater part of our knowledge 
 has been formed by contributions derived from 
 vulgar opinion and experience ; and, even at the 
 present moment, the medical practitioner is, to 
 a very great extent, directed in the treatment of 
 diseases, by rules, if not entirely empirical, par- 
 taking considerably of this character. In illus- 
 tration of these sentiments, it is generally stated 
 
AND ANIMAL LIFE. 377 
 
 that children are rendered sickly, or at least do 
 not thrive so well, by sleeping with individuals 
 far advanced in years, and, still further, that the 
 life of the latter is prolonged by such means. 
 From the following observations, it will appear 
 probable that the benefit which the one derives 
 will be at the expense of the other. The tem- 
 perature of the child is superior, and much more 
 equally diffused, and the circulation is also much 
 more vigorous than the same in an old and weak- 
 ly individual. In the latter the extremities are kept 
 warm with difficulty, the surface is pale and col- 
 lapsed, and the susceptibility to cold at this period 
 of life proves, that the source of animal heal possesses 
 neither great energy nor stability. When the 
 system, in this condition, is placed in juxta- 
 position with one that developes the strong 
 powers of life, it necessarily deprives it of a por- 
 tion of its heat, on account of its conducting 
 qualities. The additional stimulus acquired is 
 grateful to the sensations of the aged, and as it 
 tends to excite the external capillary circulation, 
 it communicates a genial warmth and new vi- 
 gour throughout the constitution, and conse- 
 quently improves the various organic functions, 
 whose office it is to oxygenate and circulate the 
 blood, or otherwise contribute towards the de- 
 velopment of the principles of life. From this 
 explanation, we perceive that existence may be 
 
378 THE LAWS OF ORGANIC 
 
 prolonged when it is ebbing from the natural 
 decay of the organs essential to its perfection or 
 continuance ; but we are not aware that the child 
 possesses a superabundance of animal heat or 
 strength of constitution; and therefore, it is 
 highly probable, when it is thus circumstanced, 
 that its health may be impaired, and the evolu- 
 tion of its future powers may be materially cir- 
 cumscribed. 
 
 CCCCL. I have already remarked that life has 
 its degrees in the same individual at different pe- 
 riods of life, and in different states of the sys- 
 tem ; and it has also its degrees in various parts 
 of the animal frame. The extremities, from the 
 effects of wounds, ligatures, or exposure to great 
 cold, are more liable to mortify than any other 
 parts of the body. As they are the farthest remov- 
 ed from the source of circulation and animal heat, 
 the vigour of the one and the extent of the other 
 are considerably modified before they reach these 
 distant parts ; and it is from this cause that cold, 
 for example, occasionally produces immediately 
 fatal effects. In this instance, the limb or the 
 toes die for want of the proper quantity of blood ; 
 consequently this fluid contains the principles of 
 life. 
 
 The above reasoning explains an experiment 
 of HUNTER, which is otherwise accounted for 
 by him. He reduced the temperature o*f the 
 
AND ANIMAL LIFE. 379 
 
 mouth from 97 to 77, by introducing small 
 pieces of ice, and allowing them to melt there ; 
 and he says that the effect would have been 
 much greater, if the hand, instead of the mouth, 
 had been thus circumstanced. The mouth, from 
 its vicinity to the heart, and from the great quan- 
 tity of blood which it receives, is cooled with 
 comparative difficulty, and it speedily regains its 
 ordinary temperature from the same cause ; but 
 the hand, from conditions precisely opposite to 
 these, is greatly and quickly affected by the 
 same means. 
 
 CCCCLL After surgical operations, or inju- 
 ries of the body, the separated surfaces very 
 frequently unite by what is called the first in- 
 tention. This desirable object is sometimes ren- 
 dered tardy, or impossible, by an impoverished 
 state of the system, or by the gloomy passions of 
 the mind. It is facilitated by whatever excites 
 agreeable feelings, or tends to invigorate the 
 powers of the system. I have already endea- 
 voured to prove, in various parts of this work, 
 that the blood, during the influence of depress- 
 ing passions, is deficient in its usual qualities, 
 because the sanguineous fluid, by the exercise of 
 such mental states, is brought to the lungs in great- 
 er quantity than natural, perverting the conditions 
 indispensable to oxygenate completely the blood, as 
 stated in the first chapter. 
 
380 THE LAWS OF ORGANIC 
 
 CCCCLII. It is stated by RICHEIIAND and 
 others, that " the increase of vital energy to an 
 injured part" indicates " the existence of a pre- 
 serving principle, incessantly watching over the 
 harmony of the functions." * 
 
 This idea seems very correct and beautiful 
 when superficially examined, or rather when not 
 examined at all ; but if we take into considera- 
 tion, that he here alludes to the blood flowing 
 to a part which is wounded by the prick of a 
 thorn, it is not difficult to bring forward a thou- 
 sand instances where such a flowing was the 
 cause of great inflammation, suppuration, and 
 death. Indeed, when such cases occur, it is not 
 our object to Increase, but to diminish the deter- 
 mination ; and if the vital principle were inces- 
 santly watching over the harmony of the func- 
 tions, how does it happen that it destroys its 
 own existence by allowing congestions or inflam- 
 mations to take place ? It may probably be as- 
 serted, that it is too weak to resist the influence 
 of powerful agents ; therefore it must be allowed 
 to be serviceable only when its contributions are 
 not particularly required. 
 
 CCCCLIII. In the preceding pages I have 
 alluded to and explained many states of the 
 system that have been regarded by the most 
 distinguished physiologists as inexplicable, ex- 
 
 * Trans, ut supra, p. 48. 
 
AND ANIMAL LIFE. 381 
 
 cept on the supposed existence of a peculiar 
 vital principle, whose attributes are like those 
 of a spirit possessing an unembodied form, sensa- 
 tion, and perception, which is continually on the 
 look out, in order to protect the body from 
 insidious attacks or dangerous breaches, but, 
 when it finds itself unequal to the contest, 
 retires and allows the assailant to devastate the 
 domains it so lately governed and beautified. 
 Having proceeded thus far in the investigation 
 of the nature of the vital principle, I shall en- 
 deavour, in the next section, to make still closer 
 approximations to a knowledge of that vivify- 
 ing principle, by means of which the organic 
 functions and the animal (of course considering 
 the immortal mind as a separate existence) are 
 maintained in the exercise of their various 
 powers. 
 
 SECT. II. An Inquiry into the Nature of that Principle 
 by means of which the System is maintained in Health 
 and Vigour. 
 
 CCCCLIV. THAT the principle of life is 
 ject to an increase and diminution, must appear 
 probable to the most superficial observer of Na- 
 ture ; but, if he investigate the subject profound- 
 ly, his doubts and probabilities will perhaps be 
 exchanged for certainties. In marking the exu- 
 
382 THE LAWS OF ORGANIC 
 
 berance of health displayed by the child in the 
 activity of organic and animal functions, he will 
 not hesitate to allow, that this apparent super- 
 abundance of powers is bestowed in order to de- 
 velope or invigorate the various organs of the system. 
 These powers are evidently much greater than 
 would be required to maintain the infantile con- 
 stitution, if this were intended to be stationary. 
 It therefore ought to be our object to ascertain 
 in what consists the superiority of the child over 
 the adult in regard to those functions that co- 
 exist with, or produce the most important changes 
 of the body. 
 
 CCCCLV. To arrive at a correct knowledge 
 of the animal frame we possess only two modes 
 direct experiment, where such is possible, or a close 
 and patient examination of cause and effect. The 
 latter means are very frequently as conclusive as 
 the former. In following such a plan, we are 
 liable to one general source of error, viz. that of 
 seizing only the apparent cause, without being 
 sufficiently aware that another, or others, may 
 intervene between it and the obvious sequence, 
 which alone can be regarded in strict relation 
 with the effect. 
 
 CCCCLVI. When the child exhibits that 
 necessary and continued activity of body and 
 mind, we observe the respirations frequent, the 
 contractions of the heart and arterial system 
 much more numerous than in after life ; and 
 
AND ANIMAL LIFE. 383 
 
 we also remark, that the surface of the body is 
 highly vascular and generally florid at this peri- 
 od. If we turn to the system in decline from 
 age, we perceive that the frequency and vigour 
 of respiration and circulation are strikingly di- 
 minished, and, still further, that the restless de- 
 sire of action, the rotundity of the muscles, and 
 the vascular and florid condition of the surface 
 of the body, no longer exist. 
 
 It can scarcely be denied, that if we lessen the 
 frequency or perfection of respiration, we shall 
 deteriorate the powers of life. The excited and 
 generally diffused circulation, in childhood, is a 
 consequence of the stimulating properties of the blood 
 and other conditions^ fully stated in Chapter IV. ; 
 and, therefore, this state of the circulating sys- 
 tem, and every organic function dependent on 
 its influence, are to be referred to the frequency 
 or perfection of respiration, as the primary source 
 of every effect. 
 
 CCCCLVII. We may next inquire how the 
 frequency of respiration can operate so as to oc- 
 casion these marked results. In the nine gene- 
 ral laws, or deductions following XXVIII. I have 
 alluded to particular states of the respiration, 
 and have endeavoured to show that certain of 
 these are the cause of the buffy or inflammatory 
 coat in blood, arising from its highly oxygenated 
 qualities ; and, moreover, when opposite respi- 
 ratory or sanguiferous conditions are present, 
 
384> THE LAWS OF ORGANIC 
 
 the blood, in harmony with such changes, does 
 not exhibit the same character, and, in many in- 
 stances, will not even coagulate* The condi- 
 tions which produce the inflammatory coat in 
 disease, are the same as those that predominate 
 in childhood simply modified. When they ex- 
 ist in disease, we have increase of temperature, 
 augmented action of the heart and arterial sys- 
 tem, a vascular or florid appearance of the sur- 
 face of the body ; and when they occur at an 
 early period of life, we have similar symptoms, 
 differing only in degree. The frequent respira- 
 tions, supposing other conditions of the system 
 favourable, as they are almost universally in 
 childhood, must be allowed to deteriorate, in a 
 given time, a greater quantity of air than when 
 these are slow or imperfect. The air which is 
 inspired contains a vivifying principle, viz. oxy- 
 gen ; and if a greater quantity of air be breath- 
 ed in a limited period, a greater quantity of oxy- 
 gen must be received by the blood in the lungs 
 in the same time ; and it is to this agent we 
 must refer the oxygenated or arterialized pro- 
 perties of the sanguineous fluid. 
 
 CCCCLVIII. In the child the arterial blood 
 is more florid than the same in advanced 
 life, or at least the venous is not so dark as at 
 this period. When the body is subjected to 
 great heat or exercise, the venous loses its ordi- 
 
AND ANIMAL LIFE. 385 
 
 nary well-marked characters ;* indeed the dis- 
 tinction, in regard to colour, between arterial 
 and venous blood, is almost lost. The cause of 
 these phenomena appears so evident, and so 
 closely connected with the effect, that it is al- 
 most impossible to refer the latter to any other 
 agent than oxygen. If this be granted, we must 
 acknowledge that the principles or powers of 
 life are to be attributed to the influence of this 
 agent. 
 
 CCCCLIX. The blood possessing under va- 
 rious circumstances a greater or less proportion of 
 the vital principle, as indicated by the activity 
 of organic and animal functions, and also by its 
 external qualities, it necessarily follows, if it be 
 highly oxygenated, and characterized by a variety 
 of effects in the living system, that it ought also, 
 when removed, to be distinguished from that 
 which is in a different condition, if both be 
 placed in precisely the same situation. I have 
 already observed that the circulating fluid in the 
 child possesses a greater portion of vitality than 
 the same in one advanced in years ; and the cor- 
 rectness of this opinion is demonstrated by the 
 following experiments of HUNTER, instituted, 
 not for the purpose of proving the present 
 point, but in order to ascertain the difference in 
 the properties of the blood at different ages. 
 
 Vide Chap. VIII. 
 
 B b 
 
386 THE LAWS OF ORGANIC 
 
 He says, " To see whether the blood in a 
 young person or an old one becomes soonest pu- 
 trid, I desired that the following trials should be 
 made. 
 
 " June 24. Some blood was taken from a wo- 
 man twenty years of age, and its surface, after 
 coagulation, was covered with an inflammatory 
 crust. 
 
 " On the same day, some blood was taken from 
 a woman aged sixty, when crassamentum was 
 also covered with an inflammatory crust. 
 
 " These quantities of blood were set by. 
 
 " The blood from the old woman putrefied in 
 two days ; that from the young woman kept 
 quite sweet till the fifth day, when it began to 
 smell disagreeably ; in this state it continued 
 two days more, and then emitted the common 
 odour of putrid blood." 
 
 " Several experiments were made in the course 
 of the summer of a similar nature with the last, 
 in all which it appeared that the blood from 
 young people kept longer sweet than that which 
 was taken from the old.*" 
 
 It must be acknowledged that the result of this 
 experiment is confirmatory of the principles laid 
 down. HUNTER endeavoured to show that the 
 blood was vital, but he did not attempt to in- 
 vestigate the nature of this property. I have 
 stated in CCCCLVI. and CCCCLVII. that the 
 
 * HUNTER on Inflammation, Vol I. p. 167. Octavo Edit, 
 
AND ANIMAL LIFE. 387 
 
 difference between the inflammatory state of 
 the blood in disease and childhood is merely in 
 degree. This opinion is almost as directly prov- 
 ed as the preceding, regarding the condition of 
 the sanguineous fluid at different ages, by the 
 following experiment of the same physiologist : 
 " I wished," he says, " to see if blood that coa- 
 gulated with an inflammatory crust putrefied 
 later than that which coagulated without it ; 
 for I conceived that the strength of coagulation 
 was something similar to the strength of contrac- 
 tion in a muscle, resisting putrefaction. For this 
 purpose I ordered the following experiments to 
 be made. 
 
 EXPERIMENT I. 
 
 " Four ounces of blood were taken from the arm, which, 
 after coagulation, had the inflammatory crust upon its sur- 
 face, and was also cupped." 
 
 EXPERIMENT II. 
 
 " On the same day four ounces of blood were taken from 
 another person's arm, which on coagulating shewed no 
 inflammatory crust on its surface. Both these quantities 
 of blood were kept, in order to see which would resist 
 putrefaction longest. 
 
 " By the fourth day, that without buff was putrefied ; 
 but the blood with the inflammatory crust did not putre- 
 fy till the seventh day." * 
 
 * Ibid. p. 166. 
 B b2 
 
388 THE LAWS OF ORGANIC 
 
 CCCCLX. In the preceding chapter on the 
 Physiology of Passion I have endeavoured to ex- 
 plain the influence of those feelings which are of 
 a depressing nature, and, therefore, on the pre- 
 sent occasion, shall allude only to such as are 
 in strict relation with the present investigation. 
 It is well known that the depressing feelings of 
 the mind disturb, according to their severity, 
 the regularity of the vital functions. If only 
 slight, the appetite is lessened or becomes fasti- 
 dious, the ordinary complexion of the counte- 
 nance is changed, and the energy of the mental 
 faculties is rendered of little avail ; but if such 
 be severe, we scarcely observe the slow and pro- 
 gressive diminution of the powers of life; the 
 individual affected sometimes dies after a few 
 days indisposition ; and in such cases it is re- 
 marked, that the blood coagulates with difficulty, 
 or sometimes not at all. It is impossible to bring 
 forward a more direct instance in illustration of 
 the influence of the mind upon the body, or one 
 that applies so immediately to the subject of vi- 
 tality. 
 
 CCCCLXI. To those who are well acquaint- 
 ed with the language of grief it is unnecessary 
 to insist particularly on the character of respira- 
 tion. When an individual is suffering from an 
 affection of this kind, his habits are retired ; he 
 finds little or nothing to interest him in the so- 
 cial circle, or in pursuing his ordinary amuse- 
 
AND ANIMAL LIFE. 389 
 
 ments or labours : if not excited by conversa- 
 tion, he remains silent, fixed in thought, and 
 continually draws profound inspirations ; indeed, 
 we perceive occasionally a series of these acts, in 
 his frequent and deep sighs. I have repeatedly 
 stated that inspirations have the tendency to 
 bring a quantity of blood greater than what is 
 natural to the chest, and the truth of this opinion 
 is exemplified in the present case. I have also 
 observed in the first chapter, that, whenever the 
 lungs possess a quantity of blood greater than 
 what is natural, the chemical changes are ma- 
 terially diminished. The influence of grief pre- 
 vents the conditions essential to a perfect 
 oxygenation of the blood, as it brings to the 
 lungs an inordinate quantity of it, and, there- 
 fore, increases on the one hand the blood that 
 has to undergo chemical changes, without augr 
 menting on the other, to the same extent, the 
 proportion of air within the lungs to produce 
 these effects. 
 
 CCCCLXII. From this explanation, it is clear 
 that the properties of the blood are deteriorated, 
 on account of the deficient chemical changes in 
 the lungs, or, in other words, that it is defective 
 in the principle of vitality, from the deficiency of 
 axygen. While a depressing emotion, like that 
 of grief, continues to occupy, or rather absorb 
 the attention of the mind, the blood is gradual- 
 ly losing its stimulating qualities ; the surface of 
 
390 THE LAWS OF ORGANIC 
 
 the body becomes pale ; the organic and animal 
 functions are feeble or irregular ; the individual 
 frequently complains of oppression in the epi- 
 gastric region, from the accumulation of blood. 
 The heart, in such cases, is often subject to pal- 
 pitation, the pulse at the wrist is remarked to be 
 very weak and small, and generally quick ; and 
 when these symptoms are well marked, the tem- 
 perature of the body, in accordance with the 
 character of the above derangements, is less than 
 in the natural state of the system. 
 
 CCCCLXIII. It would be easy to enlarge 
 on the preceding remarks, but I can scarcely 
 point out in a more perspicuous manner than I 
 have endeavoured to explain, the way in which 
 the blood has its vitality diminished for want of 
 the usual chemical changes in the lungs. Ob- 
 servations of this description are important, as 
 tending to explain the way in which the vital 
 fluid is deteriorated ; and if the present views be 
 allowed to be correct, we can now, with perfect 
 ease, speak of mental influence, not as a myste- 
 rious or immaterial power pervading the whole 
 system, but as a cause which gives rise to the 
 different phenomena, from having disturbed the. 
 regularity of the respiratory functions. The prin- 
 ciples which enable us to explain these pheno- 
 mena, by examining the strict relations existing 
 between cause and effect, are precisely the same 
 
AND ANIMAL LIFE. 391 
 
 as those by which I have, throughout this work, 
 attempted to solve many difficulties connected 
 with organic and animal life. 
 
 CCCCLXIV. In individuals of the sanguine- 
 ous temperament, we have those characteristics 
 which indicate an exuberance of vitality. The 
 strong contractions of the heart, the florid com- 
 plexion of the countenance, the development of 
 physical powers, the gaiety or cheerfulness of 
 the mind, or the occasional bursts of passion, are 
 a few of those symptoms by which this tempera- 
 ment is distinguished. The greater part of these 
 conditions are to be referred to the natural con- 
 stitution of the mind, and the peculiar circumstan- 
 ces under which it has been placed. The full 
 elucidation of this subject would present many 
 new views in regard to the temperaments ; but, 
 on the present occasion, it is sufficient to observe, 
 that if the character of the mind be cheerful, it 
 will invigorate the system, if melancholic it will 
 depress it. The mind has only one way of com- 
 municating its influence to the body, namely, 
 through the function of respiration ; and as this, or 
 a similar apparatus, is the primary source of the 
 continuance of existence in the whole animal 
 and vegetable creation, it necessarily follows, 
 that what excites or depresses its operation will 
 excite or depress the whole system. 
 
 CCCCLXV. When any of the inferior ani- 
 mals have undergone excessive exercise, as, for 
 
392 THE LAWS OF OllGANIC 
 
 example, when they have been chased or driven 
 for a great distance, it has been repeatedly prov- 
 ed that the blood will not coagulate, conse- 
 quently, that it is deprived of its ordinary vitality. 
 This phenomenon will be found to arise from 
 certain physical conditions of the blood, some- 
 what similar to those peculiar to depressing pas- 
 sions. Moderate exercise augments vitality, be- 
 cause the sanguineous fluid is favourably cir- 
 cumstanced for its more perfect oxygenation ; 
 indeed, it very often exhibits the buffy crust, as 
 in cases of inflammation ; but when this exer- 
 cise is accompanied by great debility, we have 
 other effects. 
 
 CCCCLXVI. Excessive exercise is attended 
 by a great expenditure of the properties of the 
 blood, and of those materials that the system has re- 
 ceived for nutrition. Great exercise, before it 
 gives rise to debility, is maintained at the ex- 
 pence of the nutritive qualities of the sys- 
 tem, which, under the present circumstances, 
 are more quickly dissipated than on ordinary 
 occasions. The blood is more than usually 
 stimulating ; and, moreover, its circulation is 
 augmented in every respect. The existence 
 of these causes in some measure proves, that, if 
 great exercise be long continued, the blood will 
 speedily be impoverished. If we even suppose 
 the lungs to receive the natural, or even a greater 
 quantity of oxygen, this cannot supply the want 
 
AND ANIMAL LIFE. 
 
 of those materials essential to support the gra- 
 dual loss of the constitution ; its office is to 
 act on the principles contained in the sanguineous 
 fluid, and if these be deficient the usual chemical 
 changes will also be affected. 
 
 CCCCLXVII. It is from the above causes 
 that debility follows excessive exercise ; and when 
 that condition of the system becomes oppressive 
 the regularity of the respiration is disturbed; and 
 this alteration also tends to augment the general 
 weakness, and to deteriorate still more the proper- 
 ties of the blood. 
 
 CCCCLXVI1I. In regarding oxygen as one of 
 the principal agents of the universe, through 
 whose energetic influence the animal and vege- 
 table creation are enabled to display their various 
 endowments, 1 do not by any means imagine 
 that the grand effects of its power are referrible 
 to its simple diffusion or presence, but rather to 
 its innumerable combinations with whatever is requir- 
 ed for the ultimate ends of these si/stems of Nature 
 Whether we regard the secretions of the kid- 
 neys, mucous membranes, or the liver, or whe- 
 ther we examine the qualities of the blood or 
 constitution of the solids, we observe every where 
 acids, alkalies, and a variety of other combina- 
 tions. In many chemical substances without the 
 body these are, in many instances, inert or active 
 acording to the quantity of oxygen which they 
 contain. It must be allowed, that chemical 
 
394 THE LAWS OF ORGANIC 
 
 science is even yet in its infancy; but if, thus im- 
 perfect in its analysis, it is capable of proving the 
 general efficiency or superiority of oxygen, we 
 may probably be allowed to anticipate that, at 
 some future period, it will demonstrate the cor- 
 rectness of opinions, at present little better than 
 conjectures, which, however, are occasionally of 
 great utility towards the promotion of science. 
 
 CCCCLXIX. Arterial blood is rendered as 
 dark as venous by the application of galvanism. 
 If coagulated, on the employment of this agent 
 it becomes fluid, and never again assumes the 
 same condition. Individuals are occasionally 
 killed by lightning, and in such the blood is 
 found in a fluid state. It is not improbable that 
 galvanism and lightning are of the same nature : 
 their influence on the animal economy presents 
 the same phenomena. These agents are said to 
 destroy the vitality of the blood ; and if it be 
 supposed to be the result of oxygen and its va- 
 rious combinations, no opinion is better support- 
 ed by experiments. There is scarcely a substance 
 in Nature but what is almost immediately de 
 composed by the application of a strong galvanic 
 power. We know that chemical combinations ex- 
 ist in the blood ; and we still further know, that 
 such are separated without the body into their 
 different elements by the influence of the galva- 
 nic aura. Therefore, if the blood be considered 
 
AND ANIMAL LIFE, 395 
 
 vital before we employ this agent, when these 
 chemical combinations are entire, and that it loses 
 its vitality on the application of this power, we 
 are almost necessitated to allow that vitality is the 
 result of these combinations, as it no longer exhibits 
 any of its properties when these are destroyed. 
 
 CCCCLXX. In Chapter VII. on Torpidity, 
 I have dwelt at considerable length on the par- 
 ticular influence of cold in retarding the oxyge- 
 nation and circulation of the blood ; and have also 
 endeavoured to shew in what manner warmth 
 tends to restore the enfeebled powers of life. 
 The diminution and increase of animal and orga- 
 nic functions were, in these instances, the diminu- 
 tion and increase of vitality. 
 
 CCCCLXXI. Nothing in Nature can be attri- 
 buted to chance. Harmony and beauty are ob- 
 served in the grand outlines of design, perceived 
 in those creations within the grasp of our facul- 
 ties ; and since the Supreme Being has thus won- 
 derfully constituted our frame, and given it es- 
 tablished laws, it is somewhat probable that oxy- 
 gen is the instrument which principally tends 
 to accomplish his intentions. Regarding oxy- 
 gen as a primary principle of vitality harmonizes 
 with the figurative language of Scripture, in 
 which it it is stated, that after God had created 
 man " He breathed into his nostrils the breath of 
 life.' 
 
396 THE LAWS OF ORGANIC 
 
 CCCCLXXII. Having generally investigated 
 the subject of vitality, we are now, in some 
 measure, better prepared to define it. The ar- 
 terial blood in the foetal germ is certainly pre- 
 sent before evident structural adaptations, ex- 
 cept vessels, are formed ; and, therefore, the 
 blood, or vital principle, may be said to precede 
 organization ; but it is, at the same time, the 
 result of organization, as it is derived from the 
 mother. The blood she distributes to this vital 
 nucleus is of the same kind as that which is 
 employed to secrete the gastric juice, bile, or 
 mucus. These different secretions cannot be 
 supposed to originate from different kinds of 
 blood, but must be referred to peculiar organic 
 adaptations proper to each organ, in the same 
 manner as the eye is fitted to the laws of light. 
 It forms no part of our inquiry to investigate 
 Iww the foetal system is developed. We do not 
 know the laws by which a crystal is formed, 
 which appears a much simpler phenomenon. 
 It is our province to examine the circum- 
 stances which are closely connected with the ob- 
 ject we cultivate. From having pursued this 
 plan, I am disposed to attribute vitality, or the 
 principle by means of which the system is gra- 
 dually formed and supported throughout exist- 
 ence, to qualities of or combinations existing in the 
 blood. It has also been seen, in the preceding 
 pages, that these qualities or combinations have 
 
AND ANIMAL LIFE. 397 
 
 an exciting or depressing tendency ; or, in other 
 Words, exhibit a superabundance or deficiency of 
 vital energy according to the quantity of oxygen 
 which the sanguineous fluid contains. From this 
 reasoning we are not to conclude that vitality 
 and oxygen are synonymous ; with as much 
 consistency we might state that a machine and 
 its source of motion are the same. The func- 
 tions of the animal frame are retarded or accele- 
 rated according to the quantity of oxygen ex- 
 isting in the blood, or according to its changes in 
 the lungs ; and we also observe that the diffe- 
 rent machines which man employs, whatever be 
 the power that continues their action, have a 
 jforce proportionate to the extent of the moving cause. 
 But, in these examples, there is no similarity, 
 either in the agent which operates, the materials 
 acted upon, or the effects produced. 
 
 Life is not a simple principle, but is the result of 
 compound principles and actions pervading and 
 common to every part of organized nature. 
 
398 THE LAWS OF ORGANIC 
 
 CHAP. XVII. 
 
 On Sympathy. 
 
 CCCCLXXIII. There are few subjects in me- 
 dicine that have occupied, equally with Sympa- 
 thy, the attention of the physician and physio- 
 logist. Whether the human frame be regarded 
 in the state of health or disease, certain indefinite 
 links of association seem to connect the various 
 organs of the constitution ; and the phenomena 
 which arise from the reciprocal action of these 
 organs, in their different states, are frequently, 
 to the physician, indications of practice. It is 
 scarcely necessary to enumerate the divisions 
 and subdivisions of sympathy which have been 
 proposed. Some men of eminence have endea- 
 voured to point out certain intimate relations ex- 
 isting between individual membranes of the same 
 or of a dissimilar description, between internal 
 organs and the mucous or cellular membrane, 
 or between parts that are continuous, contiguous, 
 or remote. By some the nerves and the brain 
 are regarded as the only efficient agents in trans- 
 mitting, influencing, or in maintaining every 
 species of irritation or disorder. 
 
AND ANIMAL LIFE. 399 
 
 CCCCLXXIV. It is seldom that a series of 
 propositions is altogether true or false ; and the 
 correctness of this observation is obvious, when 
 applied to the different theories concerning sym- 
 pathy. But if these had been capable of demonstra- 
 tion, or had immediately enlightened our pro- 
 fessional views, our reasonings would have been 
 less confused and indistinct. The great objec- 
 tion to the prevalent opinions with respect to 
 the laws of sympathy is, that they are either 
 gratuitous, or suggest little improvement in 
 practice. 
 
 CCCCLXXV. It is not, on all occasions, 
 easy to detect error, and, when detected, it is 
 sometimes more difficult to supply its place with 
 truth. But, in medicine, the exposure of error, 
 sooner or later, leads to the establishment of 
 truth, or gives rise to principles that are more or 
 less salutary in their influence. In this chapter 
 I shall attempt to expose many important errors 
 either committed or supported by physiologists 
 of eminence ; and, while I liberally bring for- 
 ward the mistakes of others, I shall humbly pro- 
 pose opinions that appear to me better calculated 
 to solve the most essential phenomena of sym- 
 pathy, and which also appear to have a closer 
 connection with the indications of practice. 
 
 CCCCLXXVI. Sympathy, however produced 
 by the different states of the body, I have di- 
 vided into the four following classes : 
 
400 THE LAWS OF ORGANIC 
 
 a, Sanguineous. 
 b 9 Sensorial. 
 c, Nervous. 
 d, Nervo-sen sorial. 
 
 1. By the term Sanguineous Sympathy, I allude to af- 
 
 fections produced and propagated by changes in the 
 nature, quantity, and circulation of the blood. 
 
 2. By Sensorial Sympathy, I mean certain effects originat- 
 
 ing in sensations or states of the mind subsequently 
 propagated through the medium of nerves : an ex- 
 ample of this division is the production of syncope 
 and vomiting from a mental cause. 
 
 3. Nervous Sympathy is the propagation of certain effects 
 
 accomplished by nerves alone, as in risus sardonicus, 
 arising from irritation or inflammation of the dia- 
 phragmatic nerve communicated to the seventh pair 
 of the face. 
 
 4. Nervo-Sensorial isa term employed to explain phenomena 
 
 which result from the irritation of a nerve or nerves, 
 of which the brain takes cognizance, and which 
 afterwards transmits its impressions to other organs 
 of the body. Vomiting is frequently an instance of 
 this reaction. 
 
 CCCCLXXVII. The division proposed will 
 enable us to simplify the explanation of many 
 irregular actions or states of the body ; and if the 
 views and principles be found correct after ma- 
 ture examination, they are sure to suggest an 
 improved mode of treatment in many anomalous 
 and well marked-affections of the system. 
 
 Sanguineous sympathy will shew, in a man- 
 ner more consistently than has hitherto been 
 
AND ANIMAL LIFE. 401 
 
 done, why parts that are continuous, contiguous, 
 or remote, are at times simultaneously affected ; 
 why the same or different membranes are al- 
 ternately or reciprocally influenced by disease ; 
 why disease in one organ induces derangement 
 in another ; and why the aberration of one func- 
 tion occasionally implicates the whole system. 
 
 CCCCLXXVII. There is scarcely a cot d c ion 
 of the body that is not produced by sympathetic 
 action ; irritations, inflammations, dropsies, fe- 
 vers, delirium, hemorrhagies, and a variety of 
 other affections, are said to be examples of its in- 
 fluence. 
 
 CCCCLXXVIII. The consideration of hemor- 
 rhagy, as the first illustration of Sanguineous sym- 
 pathy, will occupy the present chapter. 
 
 This disease has been divided into the active 
 and passive ; in the former, we have generally a 
 slight degree of febrile action, an accelerated or 
 full pulse, a sensation of heaviness or oppres- 
 sion in the chest or head ; but in many instances 
 the flow of blood is neither preceded nor accom- 
 panied by any of these symptoms : the other 
 seems to take place without an increased action 
 of the circulation, occurring most frequently in 
 debilitated habits or organs. 
 
 Many objections have been brought forward 
 against this division. Although it be not strictly 
 correct, yet its adoption is considerably less in- 
 
 c c 
 
402 THE LAWS OF ORGANIC 
 
 jurious in practice than many of the additions 
 and views of those who are adverse to it. 
 
 CCCCLXXIX. BROUSSAIS regards all he- 
 morrhagies as depending on an irritation of the 
 capillary vessels, consequently deems them ac- 
 tive, and endeavours to shew that debility does 
 not occasion the flow of blood. He says, if 
 debility produces hemorrhagy, that it ought to 
 occur in all cases of long continued weakness, in 
 the latter stages of life and disease ; that a para- 
 lytic limb ought to be subject to the affection, 
 which is never the case ; and still further, that 
 ecchymoses and petechias ought to characterize 
 as frequently diseases of manifest debility as 
 fevers of a typhoid nature. These arguments 
 are far from being conclusive; his favourite 
 theory, irritation, seems to obscure his reasoning 
 powers, or necessitates him to adapt to it a va- 
 riety of symptoms and conditions of the consti- 
 tution that cannot, except by force, be incorpo- 
 rated with the dangerous and exclusive views 
 implied in it. 
 
 CCCCLXXX. From the observations of 
 BROUSSAIS, one would imagine that he looked up- 
 on debility as the same in its effects, how differ- 
 ent soever the causes that produce it. Debility 
 is sometimes occasioned by excessive depletion ; 
 by want of proper nourishment ; by inflamma- 
 tory and typhoid fevers ; by slow pulmonic dis- 
 organizations, and by the gloomy passions of the 
 
AND ANIMAL LIFE. 403 
 
 mind ; but in every one of these cases, the debi- 
 lity, in relation to the condition of the solids and the 
 fluids, is as various as its causes. If we, for a mo- 
 ment, examine a patient labouring under phthi- 
 sical symptoms, we perceive the fair complexion 
 intermingled with a florid flush, white teeth, and 
 snowy hands, body easily fatigued, and mind 
 buoyant with bright hopes ; but are these the 
 symptoms we observe in the latter stage of typhus? 
 CCCCLXXXI. The nature of the sanguine- 
 ous fluid will vary with the character and dura- 
 tion of the disease ; and the state of the whole 
 system will be influenced more or less by the 
 same causes. If the body suddenly become 
 weak, we cannot expect that the blood, the fluids, 
 and the solids of the system, shall have undergone 
 those minute and extensive changes which in- 
 variably follow or accompany opposite circum- 
 stances. The healthy action of vessels may be 
 as much deranged as the fluids which circulate 
 in them ; and when this general diseased state 
 occurs, we certainly have a right to anticipate 
 the well-marked indications of asthenic affec- 
 tions. We have then petechias or ecchymoses, 
 not because the blood alone is diseased, or the 
 capillary vessels, or the various solids or fluids of 
 the body, but because the whole of them are 
 more or less affected. If this reasoning be cor- 
 rect, is it consistent to expect in a paralyzed limb, 
 or in the decrepid weakness of old age, or in the 
 
 last moments of life, the same external signs of 
 ccSI 
 
404 THE LAWS OF ORGANIC 
 
 debility ? Neither the blood nor its vessels are 
 in the same diseased condition or diminished 
 state of vitality. 
 
 CCCCLXXXII. Dr PARRY, in speaking of 
 sea-scurvy, seems to think that it may probably 
 in all cases be preceded by an increased momen- 
 tum of blood, and, still further, that petechise 
 are probably more rare in typhus than in fevers 
 of a purely inflammatory type.* 
 
 Dr PARRY'S experience does not harmonize 
 with that of the generality of observers. Petechias 
 are seldom or never found in diseases of a purely 
 inflammatory description as long as the inflamma- 
 tory type continues, but are found at the termina- 
 tion of the excited action, when the body has 
 become extremely debilitated by the previous 
 excitement and derangement of functions. The 
 severe forms of the plague are occasionally un- 
 accompanied by inflammatory action, and yet 
 we perceive in this dreadful disease the most 
 extensive consequences of asthenic influence. 
 
 CCCCLXXXIII. Dr CULLEN has endeavour- 
 ed to explain why different kinds of hemorha- 
 gies occur in different organs of the body at the 
 various periods of life ; but his arguments appear 
 to me quite unsatisfactory. He says, that youth 
 is most subject to epistaxis, because the head has 
 its organization the soonest completed ; the con- 
 sequence of which is, that the solid parts less 
 
 * Elements of Pathology and Therapeutics, p. 1 64. 
 
AND ANIMAL LIFE. 405 
 
 easily adapt themselves to a continued distend- 
 ing power, but, as this force is frequently exert- 
 ed, a rupture of vessels necessarily takes place. 
 
 CCCCLXXXIV. Hemoptysis, at a later pe- 
 riod of life, is supposed, by the same author, to 
 arise from the balance being destroyed " between 
 the systems of the aorta and pulmonary artery, 
 or between the vessels of the lungs and those of 
 all the rest of the body." 
 
 CCCCLXXXV. As hemorrhagies of a passive 
 character are often remarked at a time of life 
 much later than the two preceding, he has brought 
 forward a truly ingenious hypothesis to explain 
 the origin of these diseases ; but it is not, perhaps, 
 less chimerical than the former reasons he ad- 
 duces. He observes, that the veins in early life 
 have a greater proportional density than the arte- 
 ries, and that on this account they are enabled to 
 propel with greater energy their contents into the 
 latter, and in this way they subsequently become 
 distended or engorged, giving rise to epistaxis 
 and hemoptysis ; but, towards the decline of 
 life, the arteries have their cellular texture in- 
 creased by distention, and from this cause they ac- 
 quire a greater proportional density than the 
 veins, so that these are liable to receive more 
 blood than they can possibly circulate. 
 
 CCCCLXXXVI. In place of explaining the 
 preceding phenomena on the supposition of this 
 or that organ being the soonest completed, or 
 
406 THE LAWS OF ORGANIC 
 
 that the coats of the vessels are subjected to the 
 modifications he imagines, I prefer regarding the 
 three periods of life as periods of constitutional 
 changes in the mode of circulation, and in the degree 
 of the vitality of the blood, independent of the orga- 
 nic alterations of ivhich he speaks. 
 
 CCCCLXXXVII. In early life the circulation 
 is quick, frequent, and regular; the temperature 
 of the body is higher and more permanent than 
 that of the adult in the decline of years ; the 
 respirations are often repeated, and from the rest- 
 less mind of youth, and the variety of desires 
 and wants, the physical powers are continually 
 exercised. These conditions tend to develope 
 and strengthen the various organs of the body ; 
 the assimilating functions are more vigorous ; 
 and, from these causes, the whole arterial system 
 exhibits a degree of energy superior to that of the 
 veins. 
 
 From the peculiarities of youth, the colour of 
 the countenance, the temperature of the body, 
 and its unceasing exercise, the conditions of the 
 circulation at this time of life are designated by 
 the term external, in contra-distinction to its ge- 
 neral distribution in the later stages of existence. 
 
 Taking this view of the subject, epistaxis is 
 regarded as the effect of an increased action of the 
 whole sanguineous system, conjoined with a local de- 
 termination of blood greater than what is consistent 
 with the proper operation of the organic functions. 
 
ANIMAL LIFE. 407 
 
 The complicated net-work of vessels which co- 
 vers the internal surface of the nostrils, offers an 
 easy passage to the blood when its momentum is 
 suddenly increased ; and as no other part of the 
 body is similarly constituted, bearing the same 
 relation to this external circulation, the blood will 
 flow from the nose in preference to any other 
 part of the system.* 
 
 CCCCLXXXVIII. DrCciLLEN says, that "an 
 hemoptysis may be expected to happen from a 
 faulty proportion between the capacity of the 
 lungs and that of the rest of the body." This 
 reasoning appears perfectly correct; but I cannot 
 perceive the justness of what follows, " that an 
 hemoptysis will especially happen about the 
 time that the body is approaching to its acme, 
 that is, when the system of the aorta has arrived 
 at its utmost extension and resistance." Accord- 
 ing to this opinion, hemoptysis does not occur 
 in childhood, because the aorta accommodates 
 itself to every additional quantity of blood. The 
 thoracic viscera in infancy and childhood are ex- 
 tremely active, and from the great expirations 
 and violent exertion of individuals at a tender 
 age, we should certainly anticipate derange- 
 
 * It may probably be asked, Why does it not flow from the 
 anus ? In answer to a question of this kind, I may observe, 
 tbat the mucous membrane of the nose is highly vascular, as 
 the seat of a sense j and, from its proximity to the thoracic 
 organs, more liable to be disturbed by those causes that in- 
 crease the impetus of the blood. 
 
408 THE LAWS OF ORGANIC 
 
 ments similar to what take place at the acme of 
 life, if the extensibility and resisting power of 
 the orta and pulmonary artery were the only or 
 chief differences of the two periods. 
 
 There are three reasons which induce me to 
 dissent from Dr Cu ,i EN'S explanation : 
 
 , The comparative unfrequency of hemop- 
 tysis is one of considerable importance. If we 
 suppose, agreeably to him, that certain great 
 organic and functional changes take place at any 
 two or three periods of existence, and that these 
 are not peculiar to one individual, but are com- 
 mon to all mankind, from the operation of uni- 
 versal causes on matter precisely of the same na- 
 ture, is it philosophical to bring forward a few 
 solitary cases in support of principles that are found 
 inefficient in their general application ? 
 
 b, The second objection to this view is, that 
 the aorta and pulmonary artery are sometimes 
 found to be partly ossified without this condition 
 having been characterized by hemoptysis, or 
 any unpleasant symptom. When the parts are 
 thus disorganized, the distending power and ex- 
 tensibility must be materially diminished. 
 
 c, In the third place, HIPPOCRATES has stated, 
 that hemoptysis happens between the age of 
 15 and 35 ; and to this observation Dr CULLEN 
 assents. If hemoptysis depend on any particu- 
 lar conformation of an organ or organs, or on 
 #ny constitutional change that occurs, or is liable 
 
AND ANIMAL LIFE. 409 
 
 to occur at one part of life called its acme, it is 
 impossible or absurd to suppose that this same 
 acme shall at one time be present at 15, and at 
 another at 35 years. 
 
 CCCCLXXXIX. After having weighed ma- 
 turely the reasoning of Dr CULLEN, and having 
 also reflected on the revolutions of the system, 
 on their concomitant circumstances or subsequent 
 effects I am persuaded that there are chan- 
 ges in the mode of circulation in every period 
 of life, which satisfactorily account for their 
 accompanying or succeeding phenomena, with- 
 out referring these changes to the organic de- 
 velopment or alterations of which he speaks. 
 
 From youth to manhood the circulation has 
 evidently undergone great modification ; the re- 
 spirations are less frequent, and various organs 
 begin to assume a new or more important cha- 
 racter in the animal economy. The develop- 
 ment and support of these organs must neces- 
 sarily make a call upon the sanguiferous system, 
 and in proportion as the demands of the Internal 
 functions are increased, either by exercise or the 
 evolution of new powers, in the same ratio the 
 general or external distribution of the blood will 
 be diminished* 
 
 CCCCLXC. The condition of the circula- 
 tion at this period I would call internal, not 
 wishing to imply, by this expression, a state ap- 
 
 * Vide Chap. IV. 
 
410 THE LAWS OF OBGANIC 
 
 preaching to congestion, or, at the same time, 
 that the surface of the body is deprived of its 
 necessary blood, but simply to communicate to 
 the mind an idea of a mode of circulation pecu- 
 liar to this stage of life. 
 
 CCCCXCL Exertion, of whatever kind, has 
 a tendency to augment the flow of blood ; and, 
 whenever its motion is facilitated, a greater quan- 
 tity, in a given time, is transmitted to the lungs 
 with augmented impetus; and these, from their 
 organization and office, are calculated to experi- 
 ence the first pressure made upon the system at 
 the different periods of life. 
 
 CCCCXCII. If we take into consideration that 
 the lungs, in some individuals, are predisposed 
 to hemorrhagy, or that the circulation of blood, 
 or that the activity of the internal organs is na- 
 turally different or variable, it is not difficult to 
 explain the occurrence or absence of hemoptysis. 
 CCCCXCIII. Hemorrhoids, hemorrhagia ani, 
 and diseases of the same kind, which are called 
 passive, from the veins being the seat or source 
 of these, are accounted for by Dr CULLEN in 
 the following manner: 
 
 " The proportional density of the coats of the 
 veins to that of the coats of the arteries, is greater 
 in young than in old animals. From which it 
 may be presumed, that the resistance to the pas- 
 sage of the blood from the arteries into the veins 
 is greater in young animals than in old ; and, 
 
AND ANIMAL LIFE. 411 
 
 while this resistance continues, the plethoric 
 state of the arteries must be constantly continued 
 and supported. As, however, the density of the 
 coats of the vessels, consisting chiefly of a cellu- 
 lar texture, is increased by pressure, so, in pro- 
 portion as the coats of the arteries are more ex- 
 posed to pressure by distention than those of the 
 veins, the former, in the progress of the growth 
 of the body, must increase much more in density 
 than the latter; and, therefore, the coats of the 
 arteries, in respect of density and resistance, 
 must come in time not only to be in balance 
 with those of the veins, but to prevail over 
 them."* 
 
 CCCCXC1V. The preceding paragraph of Dr 
 CULL EN is beautifully ingenious ; but, if exa- 
 mined critically, will be found to be hypotheti- 
 cal or fallacious. The reasoning is intended to 
 show why hemoptysis does not happen after the 
 age of 35 years, and why the veins ultimately 
 become the seat of an affection similar to that 
 which has previously existed in the arteries. To 
 suppose, in the first place, that the coats of the 
 veins, in early life, have a greater proportional 
 density than those of the arteries, in order to ac- 
 count for the arterial flow of blood, is scarcely 
 consistent with the phenomena we observe in 
 the animal economy. 
 
 * CULLEN'S First Lines, Vol. II. JDCCLX.VI. 
 
412 THE LAWS OF ORGANIC, 
 
 CCCCXCV. At the period of life when he 
 imagines the veins to obstruct the current of 
 blood flowing from the arteries, in consequence of 
 which the latter are distended, the pulsations of 
 the heart are frequent and strong, the respira- 
 tions are numerous, the physical powers are con- 
 tinually exerted, and every other means that can 
 in any way increase the respiratory and circula- 
 tory functions are present. 
 
 CCCCXCVI. It is the excited state of the arte- 
 rial system, and not its engorgement from the ob- 
 stacles which the venous presents, that occasions 
 the phenomena of arterial hemorrhagy. That 
 the coats of the arteries acquire additional den- 
 sity from the power oj distention, is a supposition 
 that gains little support from the operation of the 
 same agent on other parts of the system. 
 
 CCCCXCVIl. The heart is not only unusually 
 dilated, but even enfeebled by the distending 
 force of the blood. The bladder, the intestines, 
 and the stomach, are debilitated by the influence 
 of such a power ; nor am I acquainted with any 
 organ of the body that is augmented by disten- 
 tion alone. The heart, when its parietes are 
 thickened, has been subject to an increased ac- 
 tion, which has a tendency to stimulate its own 
 individual vessels, and these receiving a greater 
 quantity of blood, or blood of more perfect oxy- 
 genated properties, give additional nourishment 
 to its muscular fibres. 
 
AND ANIMAL LIFE. 413 
 
 CCCCXCVIII. If we reason on the influence 
 of distention in the arteries themselves, it is dif- 
 ficult to conceive how this circumstance can pro- 
 duce a greater degree of tonicity or strength. 
 The distention of a vessel implies the enlarge- 
 ment of its cavity ; and whenever this condition 
 occurs, the circulation is retarded. 
 
 CCCCXCIX. Instead of the veins becoming 
 the seat of hemorrhagy from the greater propor- 
 tional density of the arteries, they are thi.s cir- 
 cumstanced owing to the arteries , hem? elves hav- 
 ing their ncrmal action deranged. If the respira- 
 tions are less perfect, and the heart becomes less 
 able to propel its contents, the veins must partici- 
 pate in the deteriorated action. In advanced life, 
 when the symptoms of passive hemorrhagy oc- 
 cur, there are many proofs present, which indi- 
 cate that the abdominal congestions are in ac- 
 cordance with the diminished activity of the 
 thoracic functions. The pulse is generally slow, 
 full, and soft, and the individual does not possess 
 the disposition or ability to exert those physical 
 powers that act as stimuli to the sanguiferous 
 system. Agreeably to these principles, we per- 
 ceive, that many debilitating causes, even before 
 the age of 35, are known to occasion the ordi- 
 nary effects of old age, by acting in a similar 
 if not precisely in the same manner upon the ar- 
 terial and venous circulation. 
 
 D. The explanation which Doctor CUL- 
 LEN gives of the preponderance of the venous 
 
414 THE LAWS OF ORGANIC 
 
 system towards the decline of life, as accounting 
 satisfactorily for the origin of apoplexy, appears 
 to be exceptionable in its principles. The know- 
 ledge of those organic states that are known to 
 predispose to this disease, and an investigation of 
 those causes that hasten its occurrence, would 
 certainly lead one to believe that the short neck 
 is favourable to the flow of the arterial blood to- 
 wards the head, and that every accidental and 
 continued agent which tends to promote the af- 
 fection acts powerfully upon the arterial system, 
 increasing the rapidity, force, and preponderance 
 of its actions. But Dr CULLEN supposes that 
 apoplexy takes place " when the powers pro- 
 moting the motion of the blood are much weak- 
 ened." 
 
 DI. Apoplexy is not a disease that is particu- 
 larly confined to the decline of life ; but, in many 
 instances, if not in the greater number, occurs 
 when an individual is in the full enjoyment of 
 his mental and corporeal faculties. Nor does it 
 happen to those whose venous system seems to 
 prevail over that of the arterial, but when this 
 has the ascendancy, or at least when it is much 
 excited. Nor, in the last place, does the mode 
 of living that predisposes to an attack of apo- 
 plexy appear to occasion, in an exclusive man- 
 ner, an equable or general turgescence of the 
 veins, except as a consequence of increased arte- 
 rial action. 
 
AND ANIMAL LIFE. 415 
 
 DIL The question has frequently been agitat- 
 ed, How hemorrhagy contributes to a plethoric 
 state of the system ? The fact can scarcely be 
 doubted ; and the knowledge of it has diminish- 
 ed materially the long-established custom of an- 
 nual depletion. It is observed by Dr CULLEN, 
 ft that the quantity of serous fluids being given, 
 the state of the excretions depends upon a cer- 
 tain balance between the force of the larger arte- 
 ries propelling the blood, and the resistance of 
 the excretories ; but the force of the arteries de- 
 pends upon their fulness and distention, chiefly 
 given to them by the quantity of red globules 
 and gluten, which are, for the greatest part, con- 
 fined to the red arteries ; and, therefore, the spo- 
 liation made by a hemorrhagy being chiefly of 
 red globules and gluten, the effusion of blood 
 must leave the red arteries more empty and weak. 
 In consequence of the weaker action of the red 
 arteries, the excretions are in proportion dimi- 
 nished, and therefore, the ingesta continuing the 
 same, more fluids will be accumulated in the lar- 
 ger vessels." 
 
 Dili. If the above explanation be correct, one 
 would imagine that the ordinary means which 
 contribute to create a state of plethora would be 
 similar to those that produce a sudden return of 
 that condition. Eut we find that individuals 
 whose pursuits require great exercise, and whose 
 mode of life is extremely simple, are not unusual- 
 
416 THE LAWS OF ORGANIC 
 
 ly stout and plethoric. Constant exercise pro- 
 motes the circulation, and increases the action of 
 the excretories. The quantity and quality of the 
 ingesta appear to have less influence in inducing 
 the effect than is generally supposed. If we even 
 granted to Dr CULLEN that the action of the 
 excretories depends on the force of the sanguine- 
 ous fluid, it would enable him to solve the phe- 
 nomena connected with the present subject ; but 
 it would certainly give rise to new difficulties. 
 The circulation of the child is particularly fre- 
 quent, and the motion of the heart strong for its 
 years, and yet it acquires, in a very short time, 
 a plethoric condition of the constitution. 
 
 DIV. Since the time of Dr CULLEN, physio- 
 logical science has introduced many improve- 
 ments, and these enable us to appreciate more 
 correctly the discoveries and the theories of pre- 
 ceding ages. Much additional light has been 
 thrown on the intricate subject of absorption, 
 which seems to prove that the vessels appropri* 
 ated to this function are ex iled or depressed 
 according to the fulness or distention of the sangui- 
 neous system. 
 
 DV. Depletion diminishes the force or ful- 
 ness of the arterial circulation ; and when this re- 
 sult is produced in the state of health, from a 
 law of the animal economy, the absorbents are 
 enabled to take up more nourishment in a given 
 time, and it is this augmented power that so 
 
AND ANIMAL LIFE. 417 
 
 quickly brings on the train of symptoms which 
 the lancet had previously removed, and not the 
 diminution of the excretions, the usual quantity 
 of the ingesta remaining the same, as imagined 
 by Dr CULLEN. 
 
 DVI. The influence of heat and cold upon the 
 body shows the extensive sympathy which is ex- 
 perienced by every part of the system in conse- 
 quence of the changes of circulation. When heat 
 is applied to the surface of the body, it stimu- 
 lates the capillary vessels to increased action ; 
 and this condition is communicated to the larger 
 vessels, and afterwards to the lungs themselves. 
 When the heart and the respiratory function 
 are indirectly excited, as in this instance, they 
 react upon the sanguineous jiuid^ and transmit it in 
 greater abundance to the capillary vessels. Dur- 
 ing this reciprocal action, the remote and exter^. 
 nal parts of the body receive a greater quantity 
 of blood ; but the rapidity of the motion with 
 which it circulates in the lungs over excites or 
 disorders the minute vessels, which chiefly com- 
 pose their substance, and gives rise to hemor- 
 rhagy. Stimuli taken within, and exercise of 
 every description, produce the same effect. If 
 we consider that the organization of the lungs 
 is extremely delicate, and that the capacity and 
 operation of these must be in harmony with the 
 different branches of the arterial and venous cir 
 
 Dd 
 
418 THE LAWS OF OKGANIC 
 
 dilation, yet at the same time are subject to 
 every alteration of the sanguiferous system, the 
 absence, and not the occurrence of hemoptysis, 
 becomes a matter of surprise. 
 
 DVII. It was formerly believed that hemop- 
 tysis was the consequence of a rupture of some 
 of the pulmonary vessels ; but modern patholo- 
 gists have clearly shewn that this circumstance 
 seldom happens except when a vessel, traversing 
 a tuberculous excavation, is partly destroyed by 
 the progress of disease. Hemoptysis is some- 
 times the consequence of an aneurism opening 
 itself into the trachea, bronchia, or substance of 
 the lungs. 
 
 DVIII. When the quantity of blood which is 
 poured from the lungs is even considerable, it is 
 regarded by L^NNEC as a sanguineous exhala- 
 tion into the pulmonary parenchyma, and is de- 
 scribed by this pathologist under the name of 
 Pulmonary Apoplexy.* 
 
 DIX. Cold, and the sudden removal of at- 
 mospheric pressure, are enumerated by CULLEN 
 among the exciting causes of hemorrhagy. It 
 is almost impossible for the former to produce an 
 active form of the affection, as this does not depend, 
 as is supposed by some, upon a state of conges- 
 tion determined by the slow and gradual influ- 
 ence of cold, but is more justly to be referred to 
 an increased action of the capillary vessels. In 
 
 * JLjENNEC del Oscultation Mediate, Vol. II. p. 45. Edit. 
 Prima. 
 
AND ANIMAL LIFE. 419 
 
 apoplexy, it is probable that great congestion is 
 present. We have frequent proofs that the 
 disease, at times, consists entirely in an over- 
 charged condition of the vessels of the head. 
 
 DX. The reasoning which is employed to 
 explain the origin of hemoptysis or epistaxis, 
 would be incorrect if applied to explain the phe- 
 nomena of apoplexy. The seat of the latter is 
 the brain, which is enclosed by the unyielding 
 parietes of the skull, and is supposed by MONKO 
 and Dr KELLIE to occupy fully the cavity in 
 which it is contained. It is therefore obvious, that 
 an accumulation will easily take place, and this, 
 though existing to a slight extent, will be imme- 
 diately indicated by the symptoms of compres- 
 sion. 
 
 DXL Epistaxis does not arise from a simply 
 congested state of the vessels, but from the action 
 of these being augmented. Nor can we attribute 
 hemoptysis to a similar condition of the pulmo- 
 nary vessels. A great number of thoracic dis- 
 eases retard the flow of blood in the lungs with- 
 out the congestion induced being accompanied 
 or succeeded by hemorrhagy. If we review the 
 ordinary exciting causes of hemoptysis, we shall 
 discover that it is the tendency of such not 
 to weaken or obstruct the flow of blood, but 
 to facilitate its motio?i, increase its strength, and to 
 give additional stimulus to its character. From 
 these, and similar considerations, we may con- 
 p d 2 
 
420 THE LAWS OF ORGANIC 
 
 elude, that epistaxis and hemoptysis have not the 
 same proximate cause as apoplexy. 
 
 DXIL It is stated, that the sudden removal of 
 atmospheric pressure distends the external blood- 
 vessels in the same manner as heat. There is a cer- 
 tain seeming coincidence in the phenomena that 
 tkese present : but if we narrowly investigate the cir- 
 cumstances in which they resemble each other, we 
 shall perceive a great difference in the origin and 
 influence of their peculiar properties. Heat does 
 not simply distend the blood -vessels, but more par- 
 ticularly rouses the circulation, and gives rise to 
 those general consequences described in DV., but 
 particularly in Chapter VIII. The removal of 
 atmospheric pressure does not immediately sti- 
 mulate the vessels upon the surface of the body, 
 but allows the blood to flow here with greater 
 facility, and gives to the vessels a degree of ful- 
 ness and distention, not unlike the appearance ex^ 
 bited by an increase of temperature ; but when 
 such is the consequence of heat, the internal or-r 
 gans are not only relieved by a diminution of 
 blood, but are likewise excited by the stimulus 
 conveyed to the respiratory and circulatory func- 
 tions ; but, in case of diminished pressure, no sti- 
 mulus whatever is communicated to these, except 
 such an improvement of energy as may follow the 
 change in the distribution of the blood. 
 
 J3XIII. Philosophers not being fully acquaint- 
 e4 with the alterations whicfy the circulation 
 
AND ANIMAL LIFE. 421 
 
 undergoes on the removal of pressure, when the 
 body is completely at rest, or when the whole 
 system is animated by exercise, have differed 
 among themselves as to the precise operation of 
 this power. When an individual ascends one of 
 the loftiest mountains, he has great difficulty of 
 breathing. The countenance is extremely flush- 
 ed, and the veins on the surface of the body are 
 much swollen. These and a variety of other symp- 
 toms are said to be the results of diminished 
 pressure ; but when the aeronaut is elevated to 
 an equal height, he does not experience the same 
 painful sensations, nor does the system exhibit 
 the same effects. The evident difference in the 
 consequences, when the body is similarly exposed 
 to the influence of the same agent, is a circum- 
 stance which militates materially against the ra- 
 tionale proposed by the most enlightened physi- 
 cians. 
 
 DXIV. The nature of these physiological 
 studies have naturally led me to investigate the 
 influence of pressure, when exerted alone, and 
 when in combination with exercise ; and the 
 principles deduced appear to harmonize the di- 
 versities of opinion previously entertained on 
 this subject. When the body is in a state of re- 
 pose, and subjected to a cold atmosphere, which 
 is always the case with the aeronaut, the flow of 
 the blood becomes more internal than external, 
 in consequence of which the diminished pressure 
 has to act upon a less quantity of sanguineous fluid, 
 
THE LAWS OF ORGANIC 
 
 and has also to contend against the influence of the 
 cold, whose property it is to constrict the capil- 
 lary vessels, and, by lessening their diameter, to 
 retard the flow of blood to the surface of the body ; 
 but when this condition of atmospheric pressure 
 is conjoined with exercise, the influence of the 
 cold is counteracted. The respiration and circu- 
 lation are much accelerated by exercise, as is uni- 
 versally known, and therefore the blood is trans- 
 mitted in greater quantity, and with superior 
 energy, to every part of the system. It is now 
 external in its distribution, and the effect of the 
 atmospheric pressure is materially augmented by 
 the addition of a new power acting in unison 
 with its own. A greater quantity of blood being 
 determined upon the surface of the body by ex- 
 ercise, and the influence of the diminished pres- 
 sure, the consequence is, that the proportion of 
 this fluid in the lungs is materially lessened ; 
 therefore its stimulating properties and circulation 
 mil be much increased. Many statements are on 
 record which clearly show that the union of the 
 two causes has been attended by epis taxis and 
 hemoptysis, and many other symptoms of san- 
 guineous disturbance ; and the rationale proposed 
 seems to be satisfactory in the solution of the 
 phenomena. The fact that hemoptysis and epis- 
 taxis occur under these circumstances is strongly 
 corroborative of the idea concerning their proxi- 
 mate cause.* 
 
 * Vide Appendix. 
 
AND ANIMAL LIFE. 
 
 CHAP. XVIII. 
 
 The general action of Emetics on the system, with 
 a Jew remarks on their efficacy in Chronic and 
 Acute Diseases. 
 
 DXV. THERE are few classes of medicines 
 that have been so universally employed as that 
 of emetics. From the earliest authentic records 
 of medical science to the present day these sub- 
 stances have been used, and occasionally extolled 
 as specifics in a variety of diseases. It is impos- 
 sible to deny the good effects which have been 
 attributed to them ; and it is not difficult to ac- 
 count for their success and general adoption at 
 one time, or for their injurious tendency and par- 
 tial reception at another. 
 
 DXVI. When our knowledge of the opera- 
 tion of medicines is narrow or inaccurate, or when 
 we are, in a great measure, ignorant of certain 
 important laws of the animal economy, our prac- 
 tice is necessarily empirical. If, at one time, we 
 have cured diseases of a certain class by emetics, 
 at another we immediately prescribe the same, 
 whenever the same or similar indications are pre- 
 sent, without being fully sensible that the means 
 which we had previously found beneficial were 
 complex in their nature, and that the affections 
 which we had to treat were also as multifarious 
 
424 THE LAWS OF ORGANIC 
 
 and variable as the seasons, the conditions of the 
 body, the severity and number of the deranged 
 symptoms, and many other modifying circum- 
 stances which had not been duly considered. 
 
 DXVII. We are too frequently misled by what 
 may be called theoutline of diseases, and too little re- 
 gulated by what may be considered the subordinate 
 features or symptoms of general or local disorders. 
 He that, at one time, cures by wholesale, will, at 
 another, destroy in the same proportion. His 
 knowledge is the only fixed and unvarying ob- 
 ject: every thing around him is continually 
 changing ; and it is therefore obvious that the 
 application of his principles will be efficient or in- 
 jurious according to the conditions of the system. 
 
 DXVIII. The subject of this chapter will be a 
 further illustration of sanguineous sympathy ; and 
 I am not aware that any other class of medicines 
 so directly proves the justness of the division of 
 sympathies I have introduced as the one under 
 consideration. By the exhibition of emetics the 
 constitution is roused or depressed to an extreme, 
 and the most characteristic phenomena attending 
 these different states belong to the sanguiferous 
 system. 
 
 DXIX. The action of emetics on the animal 
 economy might have been deduced from the ge- 
 neral principles developed in different parts of 
 this work ; but I have, on the present occasion, 
 endeavoured to demonstrate, by direct experi- 
 
AND ANIMAL LIFE. 425 
 
 ment, the nature of this action. In this under- 
 taking I was kindly assisted by my friend Mr 
 BUCHAN of Devenport. 
 
 DXX. I was induced to try the effects of 
 emetics for the purpose of ascertaining clearly the 
 state of the circulation during nausea and after 
 vomiting, and also of noting the alterations which 
 these produced upon the temperature of the body. 
 I took four grains of emetic tartar, dissolved in 
 seven or eight ounces of water. At the com- 
 mencement of the experiment the temperature 
 of the room was 59|, the pulse 77, full, and of 
 good strength : the heat of the body was 97. 
 In the space of half an hour I felt slightly sick, 
 but did not experience the least dullness or ri- 
 gor. To facilitate, if possible, the progress of 
 nausea, I took, in a very short period, between 
 three and four pints of warm water. This quan- 
 tity of liquid quickly brought on, to a trifling 
 extent, the unpleasant sensations of sickness ; but, 
 before these became painfully disagreeable, vomit- 
 ing was occasioned, but lasted only for a few se- 
 conds. After the copious ejection of the watery 
 contents of the stomach, the pulse was 100, very 
 weak and small, and the temperature of the 
 body had risen to 100g. In fifteen minutes after 
 the evacuation of the contents of the stomach, the 
 pulse was found to be 80 in a minute, small, but not 
 weak, and the temperature of the body was 99. 
 In an hour and a quarter from the commence- 
 
426 THE LAWS OF OKGANIC 
 
 merit, when I experienced no nausea or disposi- 
 tion to vomit, but certainly felt great debility or 
 weariness, the pulse was still about 80, and the 
 animal heat remained stationary at 98. I had 
 to regret, in this experiment, that the nausea 
 had not been sufficiently severe to cause its 
 ordinary and well-marked effects upon the sys- 
 tem. To obviate this incompleteness, Mr BUCHAN 
 very kindly submitted to a similar experiment, 
 and the general results were in every respect the 
 same as those already detailed, with the excep- 
 tion of the nausea ; and this continued in him, 
 oppressive and disagreeable to an extreme, for al- 
 most three hours, 
 
 DXXL At half past eleven o'clock, A. M. the 
 day succeeding the previous experiment, his 
 pulse was 66 in a minute, small, the temperature 
 of the body 98, and that of the room 63^. 
 These circumstances being accurately noted, he 
 took four grains of emetic tartar, in about eight 
 ounces of water. He did not feel the least in- 
 convenience from this quantity for more than 
 half an hour; and, being desirous to promote sick- 
 ness, he took 10 grains of ipecacuanha in a simi- 
 lar quantity of water ; but this was accompanied 
 by no unpleasant sensation. On this account the 
 same dose was repeated ; and, in three quarters of 
 an hour from the commencement of the experi- 
 ment, he complained of great coldness in the 
 back and the superior and inferior extremities, 
 
AND ANIMAL LIFE. 427 
 
 particularly the latter ; in fine, so severe was the 
 sensation of cold, that he employed muscular ex- 
 ertion for the purpose of warming himself. 
 Great sickness almost immediately succeeded this 
 state of feeling, and, during its continuance, the 
 pulse was 74, very weak and small, and the tem- 
 perature 96. After he had vomited several 
 times, the pulse was 77, still very weak and 
 small, but the animal temperature had risen to 
 98]. Nausea, with occasional vomiting, continu- 
 ed until one o'clock, at which time the pulse was 
 74, presenting the above characteristics ; but the 
 thermometer, when applied to the mouth, as 
 usual, indicated 99. 
 
 DXXII. Before I draw any conclusions from 
 these facts, I may state certain peculiarities con- 
 nected with the mode in which the thermometer 
 was influenced in the case of Mr BUCHAN. Be* 
 fore the experiment, the instrument remained se- 
 veral minutes in the mouth, without the mercu- 
 ry being raised so immediately as it generally 
 is to its usual point. To make the instrument 
 as sensible as possible, the mercury was raised to 
 about 98 before it was applied ; yet, notwith- 
 standing these means, it still required several mi- 
 nutes to raise it to the few remaining degrees. 
 When it indicated at one time 96, it seemed to 
 demand a still longer period of time before it 
 attained this point upon the scale ; but after vo- 
 miting, when the thermometer stood, at one mo- 
 
428 THE LAWS OF ORGANIC 
 
 ment, at 98^, and at another at 99, the sensibi- 
 lity of the instrument appeared proportionately 
 augmented. The gentleman, to whose animal 
 temperature I allude, is young, vigorous, and ap- 
 parently of strong constitution ; his chest is very 
 well developed, and he has not been subject to 
 any pulmonic disease whatever ; yet, notwith- 
 standing these organic adaptations for the gene- 
 ration of animal heat, and for the force and ful- 
 ness of the pulse, his temperature is generally be- 
 neath the average, and it is with the greatest dif- 
 ficulty that he can bear cold. His pulse ranges 
 from 60 to 65 in a minute, and is at all times small. 
 
 DXXIII. Having, by the preceding experi- 
 ments, observed the operation of emetics upon 
 the system, in reference to certain preconceived, 
 and, I almost venture to say, established princi- 
 ples, I hope the attempt will not be deemed pre- 
 sumptuous that aspires to regulate in future the 
 exhibition of emetics, by explaining, in a clear 
 and simple manner, the nature of their operation, 
 the organs or systems directly influenced, and those 
 that are secondarily acted upon by the changes in- 
 duced. 
 
 DXXIV. Emetics may be divided into two 
 kinds ; into those which nauseate, and into those 
 which excite vomiting. The former have always 
 been considered as depressing the circulation, 
 and the latter as stimulating it ; but it has never 
 been sufficiently ascertained in what way this is at 
 
AND ANIMAL LIFE. 429 
 
 one time depressed and at another stimulated. It 
 would seem that the nervous system occupied a 
 prominent place in the minds of those who en- 
 deavoured to explain the series of consequences, 
 as they frequently speak of sympathy being exert- 
 ed between different parts of the system. 
 
 DXXV. In the two experiments performed 
 to elucidate the operation of emetics, the pulse 
 invariably became small and weak in the stage 
 of nausea, and when this was very severe, it was 
 almost imperceptible ; it would also appear that 
 the animal heat is equally affected by those causes 
 that diminish the force and increase the frequen- 
 cy of the pulse. In my own case, after vomit- 
 ing, the thermometer rose from 98 to 100i, and 
 in Mr BUCHAN'S from 96 to 99. 
 
 JDXXVI. The perspiration which follows vo- 
 miting has been attributed, by almost all writers 
 on the subject, to a particular sympathy existing 
 between the skin and the stomach, or between 
 certain internal organs. Dr CULLEN observes, 
 " Thus we are of opinion, that there is a special 
 consent between the stomach and the vessels on 
 the surface of the body, so that the several states 
 of these are mutually communicated to one an- 
 other ; whence the action of vomiting excites 
 particularly the action of the vessels on the sur- 
 face of the body." 
 
 A more modern, and a highly distinguished 
 author, remarks, " The feeble state of the circu- 
 
4JJO THE LAWS OF ORGANIC 
 
 lation, as indicated by the pulse, and the generai 
 coldness and languor experienced during a par- 
 oxysm of nausea, are to be ascribed to those sym- 
 pathetic relations by which the brain, stomach, 
 and heart, are reciprocally influenced." * 
 
 DXXVII. Although I cannot subscribe to the 
 above opinions, yet it is with diffidence I dissent 
 from such respectable authorities. The coldness 
 which accompanies the operation of emetics, 
 arises from the same proximate cause as that which 
 is the consequence of an exposure to a low state of 
 the atmosphere. The blood, in the latter instance, 
 leaves the extremities and the surface of the 
 body, because the cold constricts the capillary 
 vessels, on which account these contain less arid 
 the internal organs more blood. In the former, 
 the ordinary mode of circulation is disordered, 
 and this necessarily communicates its derange- 
 ment to the respiratory functions ; and as the 
 alternate action of these promotes the return of 
 the sanguineous fluid to the chest, or facilitates 
 its motion to the different parts of the system, it 
 is quite obvious, that whenever those means 
 which bring the blood to the chest preponderate 
 over those which should relieve it, an accumula- 
 tion will follow 5 and it is this accumulation which 
 satisfactorily accounts for \\\e frequency and small- 
 ness of the pulse, the sensation of ch illness, and I he 
 
 * Paris' Pharmacologia, Vol. I. p- 154; 
 
AND ANIMAL LIFE. 431 
 
 oppression sometime,? experienced in the precordial 
 region. 
 
 It is not at all essential to the argument that 
 the circulation be primarily deranged, and that 
 it subsequently react upon the respiration; it 
 is probable that the latter, in the greater number 
 of instances, is, in the first place, influenced by 
 the transmission of impressions to the mind, the 
 consequence of which is, that the circulation be- 
 comes irregular from depending exclusively on 
 the conditions of the respiratory function. 
 
 DXXVIII. As nausea' increases, the pulse 
 becomes more rapid and small, till at length it is 
 scarcely perceptible. The pale and collapsed 
 appearance of the face, and the indications of 
 suppressed or incomplete circulation on the sur- 
 face of the body, are proofs that the blood is in- 
 ternal rather than external, in relation to its usual 
 distribution. The lungs receive more blood than 
 they are accustomed to receive ; and if the quan- 
 tity be much greater than usual, it is clear that the 
 heart will have to propel an augmented proportion, 
 but this is evidently less arterialized from the in- 
 creased quantity of blood in the chest, and there- 
 fore the stimulating principle is diminished. 
 This is the reason why the heart does not contract 
 and dilate energetically ; but the necessity of con- 
 tinuing to act still remains, and consequently the 
 blood is propelled in a small and gentle stream. 
 
THE LAWS OF ORGANIC 
 
 DXXIX. This view is much strengthened 
 by finding the pulse quicker, and still small, im- 
 mediately after the first act of vomiting. Dur- 
 ing the continuance of this operation, the return 
 of the blood from the head, and from other parts 
 of the body to the lungs, is retarded ; but as soon 
 as the vomiting subsides, it flows in increased 
 quantity to the chest. If, on one occasion, the 
 pulse is small and weak, because the quantity 
 and quality of the blood are altered, we ought to 
 expect, on another, that these phenomena would 
 become more apparent when the influence of those 
 changes that produce these conditions is particu- 
 larly exerted. I have shown that during nausea 
 the pulse has certain well marked symptoms of 
 debility, and have also endeavoured to explain 
 their origin. If the rationale be deemed satisfac- 
 tory, and if it be still further allowed, that a 
 greater quantity of blood Jlows to the chest after the 
 first act of vomiting, the increased frequency of 
 the pulse is not only in harmony with the opinion 
 proposed, but tends materially to strengthen the 
 principles on which it is founded. 
 
 Vomiting is always accompanied by great mus- 
 cular exertion, and the co-operation of this cause 
 is another, and probably a more efficient reason, 
 to be assigned for the increased frequency of 
 pulse immediately after the emetic effect. 
 
 DXXX. I have endeavoured to depress the 
 force and increase the frequency of the pulse by 
 
AND ANIMAL LIFE. 433 
 
 taking very deep inspirations, and, by keeping up 
 a jseries of these for one minute, I have at all 
 times produced the effect. In the space of that 
 period the pulse has been augmented twelve 
 pulsations, and its fulness and strength have been 
 proportionally lessened. This simple experiment 
 is not performed without being succeeded by 
 considerable pain in the chest : it is to me suf- 
 ficiently disagreeable to prevent a frequent repe- 
 tition of it. Our voluntary attempts can make only 
 a distant approach to those efforts and consequences 
 which are referred to the involuntary powers ; 
 but if we understand correctly the nature of those 
 means that make even an approach to an involuntary 
 sequence, we are certainly enabled to discriminate 
 much better the action of those powers that are 
 independent of the will. 
 
 DXXXI. The explanation which has been 
 proposed appears more philosophical than the 
 one which assumes that there is & particular sym- 
 pathy existing beftveen the brain, stomach, and the 
 heart. If the one proposed for the consider- 
 ation of the impartial reader be granted to 
 be true, it immediately regulates our practice ; 
 but if the other be preferred, which informs us 
 of certain connexions existing between different 
 internal organs, without, in the least, explaining 
 these connexions, we are still necessitated to re- 
 gard these phenomena as enveloped in the mys- 
 tery of occult and impenetrable causes; and, 
 
 E e 
 
434 THE LAWS OF ORGANIC 
 
 from such an imperfect knowledge of some of 
 the most important laws of the human constitu- 
 tion, it is impossible to extend the limits or im- 
 prove the principles of our profession. 
 
 DXXXII. The reasoning which I have hitherto 
 brought forward in support of the views as ex- 
 planatory of the various states of the pulse, of 
 the origin and influence of sensations, and of 
 many important symptoms connected with thesys- 
 tem during the continuance of nausea, is entirely 
 founded on sanguineous sympathy. By a similar 
 kind of investigation, and by the application of 
 the same reasoning, we shall understand every 
 other change in the circulation of the blood, and 
 in the generation of animal heat, consequent on 
 the action of vomiting. 
 
 I have already stated, that the blood from the 
 head, and from other parts of the body, is retarded 
 in its flow towards the chest when the stomach is 
 engaged in the ejection of its contents ; and, still 
 further, that, as soon as the operation ceases, the 
 blood rushes in greater quantity to the thoracic ca- 
 vity, producing a condition of the lungs almost 
 approaching to congestion ; but if the vomiting be 
 excessive , and frequently repeated, we have differ- 
 ent results. The muscular exertion which the frame 
 undergoes, in a succession of expiratory actions, 
 has the tendency to equalize the distribution, and 
 increase the stimulating qualities of the blood. 
 The blood is more generally diffused throughout 
 
AND ANIMAL LIFE. 435 
 
 the system, the superficial vessels and the extre- 
 mities receive an additional quantity, on account of 
 (he impetus with which it is propelled ; and the pulse 
 is also strong and full from the same cause, conjoined 
 with the better oxygenated state of the blood. These 
 views have been elucidated at length in various 
 parts of this work, and, therefore, do not require 
 a particular consideration on the present occa- 
 sion. As a further support to these principles, 
 I may mention the increase of the temperature 
 of the body after vomiting. The diffused glow 
 which is felt, and the profuse or gentle per- 
 spiration, cannot correctly be attributed to any 
 other causes than those which belong to sangui- 
 neous sympathy, viz. increase of temper at ure> and 
 a more equable distribution of the blood. 
 
 DXXXIII. Having thus detailed, and attempt- 
 ed to explain the different kinds of phenomena 
 which originate from the two effects of emetics, 
 it may probably, to some, appear quite evident, 
 that, as the one excites, and the other depresses, 
 or, in other words, as the former equalizes and 
 stimulates the circulation, and the latter enfeebles 
 the force of this system, there is little difficulty 
 in applying this knowledge to practice. But 
 medicine is a science that demands deep thought 
 and circumspection ; the principles by which we 
 are guided are necessarily complex, and too fre- 
 quently fallacious. And, as we have to/ act on 
 animated matter, we must pause and consider 
 
 E e 2 
 
436 THE LAWS OF ORGANIC . 
 
 still further a few other points of this important 
 subject, before we enforce the application of any 
 part to practice. As nausea has the tendency to 
 bring the blood from every part of the body to 
 the chest and abdomen, it seems reasonable to 
 suppose that this effect ought to be induced in 
 cases of apoplexy or cerebral congestions, in order 
 to relieve the head. But if we reflect that the de- 
 teriorated quality of the blood is equally as de- 
 trimental to the brain as a simple accumulation, 
 we shall perhaps think otherwise. 
 
 D XXXIV. In the condition of the lungs 
 during nausea, the blood is certainly distributed 
 in less quantity, and with diminished force, to 
 the brain ; but, as this is not perfectly arterializ- 
 ed, it will increase the lethargic symptoms which 
 are present, as these arise, in part, from the dete- 
 riorated fluid, and will, most probably, at length 
 contribute to engorge the brain, by preventing 
 the free return of the blood. 
 
 DXXXV. The division of the effects of eme- 
 tics into those that nauseate, and into those that 
 occasion vomiting, has long guided physicians in 
 the selection and employment of such medicines ; 
 but it has long appeared to me that this division 
 is insufficient to regulate our practice, and there- 
 fore the following is introduced as more definite 
 in its application. Emetics are found beneficial 
 in a variety of diseases that have few symptoms 
 in common with each other ; and from reflecting 
 
AND ANIMAL LIFK. 437 
 
 on the nature of these, and on those agents which 
 influence them individually, it seems more just 
 to divide the effects of emetics into four classes, 
 and to arrange under each a few of those dis- 
 eases which are obviously benefited by these 
 effects. The first class is 
 
 The changes both in the distribution and quality 
 of the blood, as a consequence of the influence of 
 emetics ; and the diseases arranged under this 
 head are : 
 
 1. Fever. 
 
 2. Dysentery. 
 
 3. Passive Hemorrhages. 
 
 CLASS 2. Improved action of stcernent vessels. 
 
 1. Croup. 
 
 2. Indigestion. 
 
 3. Diarrhoea. 
 
 4. Phthisis? 
 
 CLASS 3. The changes in the properties of 
 the blood. 
 
 1. Active Hemorrhages. 
 
 2. Pulmonic Inflammation. 
 
 CLASS 4. Increased action of the absorbents ; 
 in which division we have the class of drop- 
 sies arising rather from debility than evident 
 inflammation. 
 
 I am fully sensible that this division of the 
 effects of emetics is not correct in all its parts . It 
 
438 THE LAWS OF ORGANIC 
 
 would be absurd to suppose, that any individual 
 system of the body is exclusively acted upon by 
 the operation of general causes ; but it would not 
 be less absurd to imagine that every function is 
 equally affected by them. The diseases which 
 have been enumerated differ widely in their 
 proximate and remote causes, and they also oc- 
 cupy different textures or organs of the body. 
 Although these circumstances be so dissimilar, 
 yet emetics have been employed in all of them, 
 and with benefit. It is the object of the present 
 chapter to endeavour to explain the principles 
 on which emetics have been or may be useful. 
 
 DXXXVI. The changes in the distribution and 
 quality of 'the blood are conditions common to almost 
 every disease, but those enumerated under this 
 head are a few of such as exhibit these changes to a 
 greater extent than any other ; and I conceive that 
 emetics are useful only in such, as they tend to 
 alter that distribution, or improve the quality of 
 the circulating fluid. That these and subsequent 
 views be properly appreciated, it is necessary that 
 the proximate cause, symptoms, and treatment 
 of each disease be generally understood ; but as 
 these considerations would interfere with the 
 present inquiry, I shall examine them as briefly 
 as possible. 
 
 DXXXVII. Emetics are frequently exhibited 
 at the commencement of contagious or intermit- 
 tent fevers. Few remedies are so powerful in 
 
AND ANIMAL LIFE. 439 
 
 cutting short the former, and I am not acquaint- 
 ed with any, when given before the paroxysm 
 of the latter, that so generally stops or modifies 
 the progress of the symptoms. When an indi- 
 vidual is supposed to be affected with fever of what- 
 ever kind, the pulse, the respiration, the animal 
 heat, and the blood, shew unequivocal indications 
 of disorder, and, at the same time, some of the in- 
 ternal viscera are more or less conges ted ex inflamed. 
 I have already endeavoured to shew that vomit- 
 ing tends to equalize the circulation of the blood, 
 and it is almost impossible to attain this end 
 without changing at the same time the nature of 
 the fluid. If both objects be accomplished, the 
 affection is cut short before it is fully established 
 in the system ; the excess of animal heat which 
 is generated by the disease itself, and by the 
 means employed, passes off in copious perspira- 
 tion, or in the other increased secretions of the 
 body. 
 
 DXXXVIII. Dysentery is a disease concern- 
 ing whose proximate cause there is little unity 
 of opinion. Some are disposed to believe, that 
 the larger intestines are in a state of constriction 
 or spasm, and therefore consider this as the 
 proximate cause. I am inclined to believe, that 
 such a condition is to be regarded in the light 
 of effect and not cause ; others, from perceiv- 
 ing, on all occasions, inflammation, or its conse- 
 quences, believe the proximate cause to be in- 
 
440 THE LAWS OF ORGANIC 
 
 flammation of one or other of the membranes 
 that form the intestines. How much soever dis- 
 tinguished individuals may differ among them- 
 selves on this subject, it is probable that few, if 
 any, will dissent from the view which I take in 
 explaining the action of those agents that occa- 
 sion the disease ; nor will they, perhaps, consider 
 the outline which I give of the pathology of the 
 disease incorrect, if they reflect on the results of 
 dissection in such cases ; and still less, if they in- 
 vestigate the operation of those means success- 
 fully employed in its cure. Dysentery is most 
 frequent in autumn, and from this reason is 
 thought, by some, to be caused by the abund* 
 ance of fruit which this season particularly af- 
 fords. The human constitution must at all times 
 adapt itself to the great changes of the year. The 
 respiration and circulation, the secretions and 
 other organic functions have not the same action 
 in winter that they have in summer ; and, there- 
 fore, one or other of these is liable to be dis- 
 ordered, if these alterations be too severe or too 
 mild for the proper performance of its office. In 
 summer the pulse is quick and full, the animal 
 heat higher than in any other season ; and if we 
 are to judge from these and other well-marked 
 phenomena, we should state that the circulation 
 is external rather than internal at this period, or 
 that the Mood is more generally distributed over the 
 surface of the body. In autumn, there are, occa- 
 
AND ANIMAL LIFE. 441 
 
 sionally, great changes in the hygrometric condi- 
 tion of the atmosphere, in the degree of cold, and 
 also in the frequency and severity of the winds. 
 If these changes be sudden or extensive, the 
 blood will necessarily become internal rather than 
 external in its circulation, not from a regular di- 
 minution of those stimuli or excitants that main- 
 tained the former state, but from an abrupt sup~ 
 pression of them ; and as the organs on which the 
 blood is driven cannot instantaneously adapt them- 
 selves to this unusual quantity, their individual 
 functions are deranged. The mucous membrane 
 of the intestines in dysentery is invariably dis- 
 eased. It is not improbable, at this season, that 
 this membrane is more susceptible of the influ- 
 ence of those agents w r hose action I have endea- 
 voured to explain than at any other, from the 
 tendency which fruit, and indulgences of the sea- 
 sons, have to disorder its functions. If it be 
 granted, from this short and incomplete sketch 
 of the disease, that there is a state of congestion 
 either co-existent with, or subsequent to, the 
 operation of the exciting cause, it will then be 
 easy to understand why the exhibition of emetics 
 is beneficial. When these induce vomiting, either 
 at the commencement of the affection or when it 
 is fully formed, the effect is, that the sanguineous 
 fluid is more equally diffused throughout the sys- 
 tem, and as it is also better oxygenated, the in- 
 testines are not only relieved of that quantity of 
 
442 THE LAWS OF ORGANIC 
 
 blood which impedes their functions, but receive that 
 which is improved in its nature, consequently fitted 
 to promote their ordinary functions. 
 
 DXXXIX. We generally find that emetics 
 act as aperients or purgatives ; and CULLEN says, 
 that they are useful only when this consequence 
 follows their employment.* But he, and all other 
 writers on the subject, seem to imagine that this 
 effect arises from the medicines passing from the 
 stomach to the intestines, arid thus acting direct- 
 ly upon the abdominal viscera. This is certainly 
 a very natural supposition as we observe that 
 substances which are almost exclusively purga- 
 tives, appear to operate in this manner. If we 
 carefully examine the true action of emetics on the 
 general systems of the body, and also reflect on 
 the general effects which follow their exhibition, 
 we shall regard the aperient or purgative conse- 
 quence as the result of the improved condition of 
 the mucous membrane, from the influence of those 
 causes that relieve the congestion and stimulate the 
 secernent vessels of the part. 
 
 DXL. Passive hemorrhages are diseases like- 
 ly to be benefited by the use of emetics. 
 There is probably no affection to which the 
 human frame is subject that more evidently 
 arises from an altered state of the blood, or 
 
 * "As inverting the peristaltic motion, vomits are useful in 
 diarrhoea and dysentery ; but, independent of that, they are 
 probably more useful as purging the intestines, occasioning a 
 greater flow of liquors into the intestinal canal.'' Lectures on 
 the Materia Medica, by W. CULLEN, M. D. &c. MDCCLXXII. 
 
AND ANIMAL LIFE. 443 
 
 unequal distribution of it, than those includ- 
 ed in the order Profluvia. Hemorrhoids, and 
 some of the varieties of menorrhagia, appertain- 
 ing to the passive kind, have, in many instances 
 been much relieved, if not cured, by the action of 
 vomiting. As I have already stated the manner 
 in which vomiting influences the mode of circu- 
 lation and quality of the sanguineous fluid, it is 
 unnecessary to dwell longer on the individual 
 diseases belonging to this class. There are seve- 
 ral other diseases, not in the least alluded to, 
 in which vomiting has been, or may be, found 
 beneficial, if judiciously prescribed ; but, as it is 
 my intention, at the present moment, to select 
 only a few to illustrate the consistency of the 
 views, many disordered states of the body must 
 necessarily be overlooked. 
 
 DXLT. We now come to the consideration of 
 the beneficial effects of emetics in croup, diarrhoea, 
 and indigestion, belonging to the second class, 
 improved action of secernent vessels. Emetics, in the 
 former of these diseases, have been employed, in 
 every stage of it, with decided utility. When 
 persevered in at the commencement of the symp- 
 toms, the diseased secretion, which ultimately 
 becomes what is called a false membrane, is not 
 allowed to form, because the nature of that which 
 is poured from the mucous follicles is consider- 
 ably improved ; or, if we suppose this membrane 
 to be generated, the same means are efficacious, 
 
444 THE LAWS OF ORGANIC 
 
 because the quality or character of the secretion 
 is, in the same manner, altered ; and, whenever 
 this effect occurs, the membrane becomes less ad- 
 herent to the internal surface of the trachea, be- 
 cause the diseased matter which connected the two 
 is displaced by what is healthy. Vomiting may 
 sometimes be the cause of removing this, by the 
 agitation which attends its operation ; and it will 
 materially facilitate this result, if the mucous 
 membrane to which it is attached has experi- 
 enced the more extensive and previous influence 
 of those agents that regulate the secretions by im- 
 proving the qualities or distribution of the blood. 
 DXLII. The mode in which the secretory 
 functions are acted upon by vomiting, is not, on 
 all occasions, easy to explain. The following 
 reasons, which are assigned, may probably be 
 considered to make an approach towards a cor- 
 rect explanation : Inflammation is never absent 
 in croup ; indeed, this is the nature of the dis- 
 ease ; and, whenever any part of the body be- 
 comes the seat of inflammation, it is always ac- 
 companied by an increased action, or congested 
 condition of the blood-vessels. The increased 
 action probably depends on an increased quantity 
 of blood which these receive, this also being of a 
 more stimulating description than usual ; and the 
 congestion may happen when the vessels are not 
 enabled to circulate the blood transmitted to them, 
 this, on the other hand, being of a less stimulating 
 
AND ANIMAL LIFE. 445 
 
 kind. But, whether we regard the vessels in a 
 state of augmented action or of congestion, we 
 may assert, with truth, that these possess a more 
 than ordinary quantity of blood. Either of these 
 states of inflammation being supposed, emetics, 
 when carried to their fullest extent, will distri- 
 bute the blood more universally, from this being 
 of a more stimulating kind, combined with the 
 muscular exertions of the body ; and, if distant 
 and superficial vessels receive a greater quantity 
 from these causes, those vessels that previously 
 received too much will be deprived of a portion 
 of their superabundance. It is in this manner 
 that rubefacients are supposed to act ; and if 
 means which are applied externally, in the vici- 
 nity of an affected part, disburthen overloaded 
 vessels, or modify their action, it is certainly al- 
 lowable to suppose that other means, which 
 operate in a similar manner, but to a much 
 greater degree, ought to be followed by similar 
 results. 
 
 DXLIII. The function of digestion is not un- 
 usually accelerated by emetics ; but as it would 
 occupy a great deal of time to develope the views 
 connected with the origin and influence of its 
 derangement, and, still further, to do ample jus- 
 tice to the principles by which we should be 
 guided in its treatment, I shall refrain from mak- 
 ing any observations at present on this import- 
 ant subject. 
 
446 THE LAWS OF ORGANIC 
 
 DXLIV. Emetics have sometimes been em- 
 ployed, and, with advantage, in different cases of 
 diarrhoea. This disease may be produced by a 
 variety of causes ; but it is not improbable that 
 the proximate cause is the same, with slight modi- 
 fications, in every instance, viz. a morbid increase 
 of action in the secernent vessels of the intestines. 
 When indigestion and crudities of the stomach 
 have been present in this disease, they have 
 generally been regarded as the exciting causes ; 
 and, in order to remove them, vomiting has been 
 recommended.* It is impossible to deny that 
 indigestion and crudities of the stomach have 
 very frequently occasioned this condition of the 
 system. If the stomach, from being oppressed 
 either by quantity or improper quality of food, 
 have its ordinary functions disordered, its con- 
 tents will not be so perfectly concocted as usual, 
 and these, therefore, are likely to irritate the se- 
 creting surface of the intestinal canal. But aU 
 though such causes as these may occasionally ex- 
 ist to produce diarrhoea, yet, I am disposed to 
 think, that the debilitated or deranged state of 
 the system is to be regarded as the principal 
 condition which gives rise to the different dis- 
 orders of the abdominal viscera. If this view be 
 allowed to be correct, emetics have a more ex- 
 tensive influence upon the animal economy than 
 
 * Vide CUJ.LEN'S First Lines of the Practice of Physic, 
 
 MCCCCXCIX. 
 
AND ANIMAL LIFE. 447 
 
 the mere rejection of crude matters from the sto- 
 mach. By the operation of such agents, the 
 quality and circulation of the blood undergo mate- 
 rial changes, the consequence of which is, that 
 digestion is improved from the better secretion 
 of gastric juice, and at the same time, and from 
 the influence of the same changes, the functions 
 of the rest of the abdominal organs are propor- 
 tionally benefited. 
 
 DXLV. I have already stated, that the pre- 
 sent classification cannot be considered correct in 
 all its parts. As our knowledge of the manner in 
 which the exciting causes of diseases affect the 
 system is rendered more exact, we shall be en- 
 enabled to speak with more confidence of the 
 general and particular effects of emetics. The 
 greater part of the treatment in phthisis, whether 
 local or general, promotes an equable distribution 
 of the blood. The warm bath, exercise, blisters, 
 and stimulants, are evidently to be referred in their 
 operation to the principle of altered circulation. 
 Both the stages of emetic effects have an ac- 
 knowledged control over the course of the 
 blood ; but unless we possess clear and accurate 
 ideas concerning the pathology of consumption, 
 it will be impossible to apply either of these 
 stages or general divisions of emetics to the relief 
 or cure of the symptoms. 
 
 DXLVI. It is, perhaps, of little moment to 
 our mode of treatment, whether we suppose the 
 tubercles or degenerations of the lungs to be the 
 
448 THE LAWS OF ORGANIC 
 
 consequence of inflammation, or of a scrophulous 
 or peculiar predisposition, if these be fully formed. 
 But when the first symptoms of the affection are 
 slightly developed, the consideration of the na- 
 ture of those causes to which these are attribut- 
 able becomes an object of imperative investiga^ 
 tion. If, in the first stage of phthisis, a slow 
 inflammatory process be going on, it would seem 
 imprudent to apply means that tend to accelerate 
 this condition ; but if disease be gradually de- 
 stroying the healthy structure of the lungs, with- 
 out the sanguiferous system being in any degree 
 excited, we may be enabled to employ certain 
 powerful agents that would apparently be im- 
 proper in the other case. It was the opinion of 
 LJENNEC, that this disease was seldom or never 
 radically cured unless the tubercles have passed 
 through the various steps of degeneration to the 
 formation of a cavity, the membranes of which 
 protect the pulmonary tissue from further ra- 
 vages, and the purulent matter which they secrete 
 escapes through the communication existing be- 
 tween the bronchial ramification and the cavity 
 itself. The obliteration of this communication or 
 cavity constitutes a perfect cure. 
 
 DXLVII. If we follow the opinion of Dr 
 ALISON, supported by a variety of well establish- 
 ed facts, which seem to show that tubercles are 
 more frequently the effects of inflammation than 
 of any other cause, we shall be influenced accord- 
 
AND ANIMAL LIFE. 449 
 
 ingly in our remedial measures. It has been 
 stated, that, in all cases of nausea, the circulation 
 is depressed, because the lungs contain a greater 
 quantity of blood, or blood not oxijgenated to its 
 usual extent. The existence of both states is 
 most probable. If inflammation be present, can 
 we diminish the excited action of the morbid 
 part by persevering in a long course of nauseat- 
 ing medicines ? This practice has been found use- 
 ful in pneumonia ; but is the analogy between the 
 two affections sufficiently close to allow of the 
 same treatment ? If inflammation be the cause of 
 the disordered symptoms in both instances, there 
 is a manifest difference in the extent and seve- 
 rity of the disease, and also in the general conse- 
 quences. 
 
 DXLVIII. I am disposed to regard the follicles 
 of the mucous membrane, or at least those or- 
 gans appropriated to the secretion of mucus, 
 and which must be supposed to exist throughout 
 the minute bronchial tubes,* as the primary seat 
 of acute or chronic inflammation, producing or 
 concomitant with phthisis. These, by a deter- 
 mination of blood to the lungs, whether from 
 
 * " In most mucous membranes are found minute oval or 
 spheroidal bodies, sligbtly elevated, and presenting an orifice 
 leading to a blind or shut cavity. As they are believed to se- 
 crete a fluid analogous to or identical with raucus, they are 
 named mucous glands. In the state of health these bodies are 
 so minute that it is very difficult to recognize them. 1 have 
 seen them, nevertheless, in the tracheo-bronchial membrane, 
 by the eye and by a lens." Elements of General and Patho- 
 logical Anatomy, By DAVID CRAIGIE, M. D. 
 
 rf 
 
450 THE LAWS OF ORGANIC 
 
 cold or any internal derangement, have their 
 natural action disordered,~the consequence of 
 which is, that an unhealthy secretion is poured 
 out, and probably in greater quantity than is 
 compatible with the well-being of the lungs. 
 This secretion, in the course of its progress, will 
 tend more or less to destroy the permeability of 
 the air-cells in the vicinity of the disease, and 
 will materially contribute to form the various 
 kinds of engorgement particularly described by 
 ANDRAL and LZENNEC. 
 
 DXLIX. If this pathological view be allowed 
 to be correct, or if chronic inflammation be sup- 
 posed to constitute the disease, in considering 
 the effects, without in the least ascending to the 
 primary cause, our practice in endeavouring to 
 remove the affection will be directed by the 
 knowledge we possess of the nature of those con- 
 sequences induced by chronic inflammation. It 
 will teach us, that those means which improve the 
 follicular secretions will the most speedily restore 
 the healthy function of the lungs. As the effect 
 of nausea is to furnish blood of an inferior qua- 
 lity to the thoracic organs, or rather to engorge 
 than to free them from a partial or general con- 
 gestion, it is probable that it would not facili- 
 tate, if it did not retard, the object that we have 
 in view. Vomiting appears well calculated to 
 benefit the patient. The improved condition of 
 the blood, and its more equal diffusion, are cir- 
 
AND ANIMAL LIFE. 451 
 
 cumstances which will tend to stimulate and 
 relieve the vessels, whatever be their natural 
 functions ; and if these take upon themselves a 
 healthy action, the incipient tubercles, or mass 
 of pulmonary degeneration, will gradually dis- 
 appear. That state of the blood which promotes 
 a healthy secretion will also excite the absorb- 
 ents ; and it is probably the combination of those 
 two powers that dissipates the local and general 
 symptoms of consumption, The disease occa- 
 sionally becomes latent in its effects, or appa- 
 rently inactive : and whenever the exciting cause 
 is augmented or applied, we have then the usual 
 indications of derangement. The different means 
 employed may retard the farther progress of tu- 
 berculous accretion, but may not act to an ex- 
 tent sufficiently great to remove what has al- 
 ready been deposited. 
 
 DL. Gentle exercise of every description, 
 and a sea voyage in particular, are recom- 
 mended in this affection, and have been found 
 more efficient in relieving or curing the symp- 
 toms than the exhibition of any internal medi- 
 cines, or external application. The manner in 
 which these influence the constitution is to be 
 explained only on the assumption that these 
 equalize the circulation, and improve the quali- 
 ties of the blood. In a sea voyage, vomiting is 
 not at all unfrequent ; and if the patient derives 
 any benefit from being several months upon the 
 
 rf 2 
 
453 THE LAWS OF ORGANIC 
 
 sea, I am inclined to believe that no small part 
 of the amendment arises from the repeated oc- 
 currence of that action. 
 
 I have been led to this opinion, from consider- 
 ing the action of emetics on the circulation of 
 the blood ; and the following observations of Dr 
 REID, on the cases enumerated by Dr GIL- 
 CHRIST on the benefit of sea voyages to con- 
 sumptive patients, are corroborative of the prin- 
 ciples. " The patients were generally sea-sick, 
 and vomited much bile ; and in some the good 
 effects ceased when they grew familiar to the 
 ship's motion, and were no longer sea-sick. He 
 relates the case of a consumptive patient who 
 went to sea three times, the distance ten leagues ; 
 each time he was sick, vomited bile, and was 
 cured of his disease. In the last, where the pa- 
 tient was at sea only five or six hours, the effects 
 could not proceed from the air or exercise."* 
 
 DLL The above observations, with respect to 
 the use of emetics, are supposed to apply to the 
 disease at its commencement only, or before the 
 parenchyma of the lungs is very much disorgan- 
 ised. At a later period I should not expect 
 equal success, and, in some instances, should not 
 be surprised if they occasioned injurious conse- 
 quences. 
 
 DL1I. Changes in the properties of the blood. 
 That the sanguineous fluid is capable of being 
 * WILSON on Febrile Diseases, p. 544. 
 
AND ANIMAL LIFE. 455 
 
 rendered more stimulating than natural, can 
 scarcely be called in question ; and, in different 
 parts of this work, I have developed principles 
 which explain the mode in which the blood be- 
 comes unfit for the purposes of the system, on 
 account of its deteriorated qualities. Emetics, if 
 they simply cause nausea, will either arrest or 
 retard the flow of blood in all cases of active he- 
 morrhagy. The truth of this is observed in ve- 
 nesection accompanied by faintness. In this 
 instance the stoppage arises from the circulation 
 being generally depressed ; the blood has the 
 tendency to move towards the chest and internal 
 viscera in greater quantity than usual: and 
 if the feeling of nausea be continued for a 
 long time the blood becomes less stimulating; so 
 that we have two reasons why emetics, confined 
 to nausea, ought at all times to be prescribed in 
 active hemorrhage. The one is, that the extre- 
 mities and the superficial vessels receive less of the 
 sanguineous fluid ; and the other, that the super- 
 abundance, by surcharging the lungs, prevents the 
 ordinary degree of oocygenation, and, on that ac- 
 count, the heart does not propel the blood with its 
 won fed energy. 
 
 DLIII. Emetics have been recommended in 
 pneumonic inflammations, by several distinguish- 
 ed continental physicians; by some for the purpose 
 of exciting nausea ; by others of producing vomit- 
 ing. It is extremely difficult to say whether the 
 
454 THE LAWS OF ORGANIC 
 
 beneficial effects are to be attributed to the for- 
 mer or to the latter, as it is seldom that we have 
 either of these consequences independent of the 
 other. In 1824 and 1825 1 attended to the prac- 
 tice of LJENNEC, at the Hospital of La Charite', 
 during which time he treated inflammation of 
 the lungs principally by nauseating doses of tar- 
 tar emetic, and certainly with success. In the 
 greater number of the cases, slight vomiting was 
 also occasioned. 
 
 DLIV. Inflammation of the pulmonary pa- 
 renchyma differs little in its stages from the same 
 process in every other viscus of the system. The 
 blood-vessels, in the first instance, are more than 
 usually stimulated ; but, subsequently, the in- 
 creased action diminishes, and the vessels are en- 
 gorged. These two important stages are better 
 illustrated by pneumonia than by any other 
 affection with which I am acquainted. The rale 
 crepitant is the distinguishing characteristic of 
 the incipient symptoms ; and it is not improba- 
 ble that this peculiar sound arises from the aug- 
 mented impetus of the blood, its greater quan- 
 tity, and some slight obstruction to its course. 
 When the disease passes from this condition into 
 that in which some part of the delicate texture 
 of the lungs has become impervious to the air, 
 the circulation is considerably impeded, and the 
 vessels are ultimately congested, giving to the 
 chest a dull sound on percussion. 
 
AND ANIMAL LIFE. 455 
 
 DLV. From the nature of these two ge- 
 neral indications, I am inclined to think, that 
 the success of vomiting at the commencement of 
 inflammation of the lungs depends much on the 
 existence of peculiar circumstances. If the dis- 
 ease be not very severe, or if a copious perspira- 
 tion succeeds the exhibition of the emetic, it 
 may be highly beneficial, as it will regulate the 
 distribution of the blood, and remove a portion of 
 the preternatural heat of the body ; but if we pre- 
 scribe these means when the individual is highly 
 plethoric, and the inflammation is intense, with- 
 out being assisted by a profuse sweat, we shall 
 endanger the life of the patient. At this period 
 of the symptoms, nausea will be found useful, as 
 it depresses the circulation, and diminishes the sti- 
 mulus of the blood ; but when we have every rea- 
 son to believe that the pulmonary tissue is con- 
 gested, the operation of vomiting is to be prefer- 
 red. The tendency of this action is, as previ- 
 ously stated, to dis bur then the lungs 3 by equalizing 
 the circulation of the blood, and by improving its 
 qualities. 
 
 DLVI. The practice of the continental phy- 
 sician has not been equally serviceable in Eng- 
 land. The varieties of climate, food, and man- 
 ners, modify very much the success of gene- 
 ral principles. Acute inflammatory diseases, 
 in France and Italy, are more easily controlled 
 by the aid of moderate means than the same in 
 our own country. The substantial and invigo- 
 
456 THE LAWS OF ORGANIC 
 
 rating regimen of our less genial climate, while 
 it fortifies the constitution against almost every 
 inclemency of the seasons, strengthens also the 
 same against the influence of remedial measures, 
 in the state of disease. There are, however, many 
 instances in which the continental practice with 
 regard to emetics may be adopted with advan- 
 tage. When the patient is naturally feeble, or 
 debilitated by a tedious plan of treatment, vo- 
 miting or nausea may enable us to arrest or re- 
 tard the progress of the disease. 
 
 DLVII. In glancing at the following sub- 
 ject, increased action of the absorbents, there are 
 many difficulties to render the investigation in- 
 complete. Our anatomical knowledge of those 
 vessels which exhale or absorb any of the fluids 
 of the system is necessarily very imperfect, from 
 the minuteness of the objects ; and our acquaint- 
 ance with the laws by which they are regulated 
 is far from being satisfactory. The labours of 
 CRUICKSHANK, BAILLIE, PARRY, BLACKALL, 
 and AYRE, have of late years enabled us to make 
 important approximations towards a knowledge 
 of those conditions of the system which predis- 
 pose to, or occasion an accumulation of serum. 
 The weight of authority inclines to the opinion, 
 that the capillary vessels are in a state of conges- 
 tion or inflammation in those cases in which 
 dropsy is induced.* 
 
 * Vide Chap. XXIII. $ I. Serous Membranes. CRAIGIE'S 
 Elements of General and Pathological Anatomy. 
 
AND ANIMAL LIFE. 457 
 
 DLVIII. It was the opinion of Dr CULLEX, 
 that dropsy was to be attributed either to increas- 
 ed exhalation or diminished absorption ; and this 
 view is not at all improbable. We know that 
 different processes are continually going on in 
 the system; for example, that one set of vessels is 
 employed in absorbing, and another in secreting 
 or exhaling. These facts naturally led the mind 
 to conclude, that if we increased the action of the 
 latter, or diminished that of the former, we should 
 have the same results. The reasoning is proba- 
 bly rather mathematically than physiologically 
 correct ; it certainly throws little or no light on 
 the pathology of the disease ; and unless the con- 
 tributions of others in this department had been 
 of a more definite description, our practice in 
 regard to dropsy would not have been improved. 
 As it is now ascertained that congestion or in- 
 flammation of the capillary vessels is, in the 
 greater number of instances, the cause of dropsy, 
 we are enabled to bring into operation some of 
 the most powerful means we possess for exciting 
 or depressing the powers of the system according 
 to the character of the symptoms. Depletion, 
 sudorifics, and emetics are the most efficient 
 agents we possess, when judiciously employed, for 
 removing an inordinate exhalation of serum, and 
 for re-establishing a healthy action of the secre- 
 tory and absorbent organs. If we endeavour to 
 enquire how congestion gives rise to serous accu* 
 
458 THE LAWS OF ORGANIC 
 
 mulations, we are immediately lost in conjectures 
 or fanciful opinions. It is much better, in the 
 present state of physiologial science, to seize and 
 act on what is certain, and, unless the facts which 
 are possessed allow us to secure a step beyond 
 these, to rest here. 
 
 DLXI. Emetics were formerly more fre- 
 quently used in dropsical affections than at the 
 present day. Fashion, which regulates the most 
 trifling concerns of mankind, has gradually in- 
 fluenced the employment of emetics that regard 
 the powers of life. Every class of medicines is 
 subject to these changes of favour, and from 
 very obvious causes. By experience, or chance, 
 it is discovered that particular substances or 
 means act almost as specifics in this or that kind 
 of diseases. This .fact is no sooner proved than 
 the practice is immediately employed generally by 
 others in the same class of diseases : in some it 
 is found to be beneficial, but in the greater num- 
 ber to be injurious or inefficient. When physiolo- 
 gy and pathology have made us better acquainted 
 with the natural or morbid action of the most im- 
 portant functions of the animal economy, we 
 shall then see more clearly than we do, even at 
 present, the absurdity of prescribing remedies, 
 however much extolled, without taking into con- 
 sideration, the varieties of constitution, the influence 
 of pursuits or habits, the extent or character of the 
 disease, the exciting cause, and the season of the 
 
AND ANIMAL LIFE. 459 
 
 year in which the affection occurs. From want 
 of these considerations, medicines of few virtues 
 have occasionally been praised as specifics, and 
 others deserving of this character have been 
 thought to be perfectly harmless. 
 
 DLX. Although inflammation or conges- 
 tion may be the cause, in the greater number of 
 cases, of serous effusions, yet I am disposed to 
 think that these, independently of obstacles to 
 the free circulation of blood, are occasionally the 
 consequence of debility, without this being cha- 
 racterized by either of the above conditions. 
 This opinion is supported by MASON GOOD ; but 
 the authority of this physician, in regard to phy- 
 siological or pathological subjects, cannot be con- 
 sidered great. Debility generally induces con- 
 gestion in those tissues of the body that exhibit 
 a dropsical diathesis. 
 
 DLXI. Other substances besides those which 
 are employed as emetics, such as digitalis, squills, 
 and tobacco, are frequently used, and with good 
 effect, in the different kinds of dropsies. These me- 
 dicines have one common tendency, viz. to produce 
 nausea, and consequently to act powerfully on 
 the sanguiferous system. If the diseases, in these 
 cases, be the result of an inflammatory action, 
 the changes in the distribution and qualities of 
 the blood will tend to destroy this condition ; and 
 in proportion as this is accomplished, the capil- 
 lary vessels will return to their normal state. 
 
460 THE LAWS OF ORGANIC 
 
 This reasoning is intended to apply principally 
 to inflammation supposed to be accompanied by 
 an increased action in the vessels affected, and 
 not when these are particularly oppressed by 
 congestion. If the latter condition be imagined 
 to be present, vomiting will be beneficial, as the 
 efficacy of its operation is communicated to the 
 circulation and properties of the blood, improv- 
 ing the irregularity of the one and the deficient 
 stimulating agency of the other. 
 
 DLXII. If we, for a moment, lay aside the 
 theories of inflammation, and also the considera- 
 tion of the manner in which different causes act, 
 that predispose to or excite dropsy, there are 
 two states of the system which co-exist with, or 
 characterize, the different species of this general 
 class of diseases, too important to be overlooked. 
 In the one, we have unequivocal symptoms of in- 
 flammation ; in the other, the absence of every 
 sign indicative of excited action. The former has 
 been proved to be most successfully treated by 
 those medicines and measures that lessen the 
 inflammatory action, such as by digitalis, squills, 
 and tobacco, and also by the frequent abstrac- 
 tion of blood. The latter, apparently depending 
 on manifest debility, has been prescribed for in 
 almost every possible way. In regard to this 
 the treatment is continually changing, as no par- 
 ticular line of practice has been discovered to 
 authorise the physician to persevere long with 
 
AND ANIMAL LIFE. 461 
 
 confidence in any plan, unless attended by al- 
 most immediate improvement of symptoms. 
 
 DLXIII. From obvious local effects, we are 
 sometimes enabled to estimate the nature and 
 extent of general effects, which are otherwise 
 not to be appreciated, produced by the opera- 
 tion of those causes which are supposed to have 
 occasioned consequences only of a circumscribed 
 character. Vomiting has often been found use- 
 ful in dropsies of the scrotum and ovarium. 
 The good result has generally been attributed to 
 the sympathy existing between the stomach and 
 these organs of the body. The disease is readily 
 traced to those causes which derange the circu- 
 lation of blood in the part ; and I have already 
 endeavoured to prove, by direct experiment, that 
 vomiting has a more extensive action than the 
 mere agitation of the system, or the awakening 
 of any mysterious sympathy. Its operation tends 
 to improve the properties of the bloodby diminish- 
 ing the proportion existing in the lungs, agree- 
 ably to the principles of the first chapter, and it 
 also tends to equalize the distribution of the same 
 throughout the body. These two important 
 conditions are not confined to any single organ 
 of the system, but are common to every viscus 
 and tissue. Is it not, therefore, probable that 
 the accumulated serum disappears from an ex- 
 cited action in the absorbents, derived exclusive- 
 ly from these two conditions of the sanguiferous sys- 
 
462 THE LAWS OF ORGANIC, &C. 
 
 tern ? If twenty such local diseases affected the 
 body at the same time, they would all be simi- 
 larly benefited by these general alterations. 
 
 DLXIV. If the serous accumulation be as- 
 cribed to diminished absorption, we possess no 
 agents that are so well calculated to excite the 
 diseased function of the absorbents as the whole 
 class of emetics ; or if we suppose this to arise 
 from increased secretion or exhalation, the same 
 means will be equally efficient in correcting the 
 disordered function. It may probably be ex- 
 pected that I should explain more particularly 
 how the absorbents and secernents are affected 
 by the exhibition of emetics. In the present 
 state of our physiological knowledge, it is much 
 better to collect and adhere to a few established 
 facts than to attempt to form a complete sys- 
 tem by the assemblage of vague opinions and 
 fanciful hypotheses. 
 

 APPENDIX. 
 

APPENDIX. 
 
 IN XI. XII. page 8 and 9 I have spoken of the in- 
 fluence of inspirations when they preponderate either in 
 number or perfection over the expirations. I have observed 
 that, in such cases, they have the tendency to determine the 
 blood to the internal organs. It may appear to some impos- 
 sible that either expirations or inspirations can have an as- 
 cendancy, since it seems necessary that the quantity of air 
 expired, must, upon the whole, be equal to that which is in- 
 spired. But, if we carefully consider the phenomena which 
 accompany either of these respiratory acts, we shall be con- 
 vinced of the correctness of the above statements. When an 
 individual speaks vehemently, or runs violently, he very soon 
 exhibits shortness of breathing. We perceive that the chest 
 and the shoulders, immediately after the exercise, are raised 
 with great force, arising from the very deep inspirations 
 which the individual is necessitated to make, in order to 
 re-establish in the lungs the ordinary quantity of air, 
 which has been expended in those efforts of the system at- 
 tendant on running and vehement speaking. Most indivi- 
 duals can count 30 or 40, commencing with unit, without 
 taking one inspiration. When they arrive at the limit be- 
 yond which they cannot pass, they are observed to make a 
 very deep inspiration, which draws in at one time the same 
 quantity of air which had been expelled by 30 or 40 previous 
 
 Gg 
 
APPENDIX. 
 
 expirations. The proof of this is, that they can recom- 
 mence counting with facility. In this illustration we per- 
 ceive that one inspiration is equal to 30 or 40 expirations, 
 therefore we can say that an inspiration is perfect or com- 
 plete according to the effects which it produces. The 
 orator can speak for hours without experiencing the want 
 of breath ; but this circumstance is evidently to be attri- 
 buted to the constant pauses, inseparable from temperate 
 or even energetic speaking. Inspirations may preponder- 
 ate either in number or perfection, from different causes. 
 In one instance, the momentary depressing states of the 
 mind, in the other similar mental conditions, but of a less 
 acute nature, as for example grief, will occasion them. In 
 the latter, the occasional sighs are Inspirations, which in- 
 dicate, in many circumstances, a disordered state of the 
 circulation of blood In the lungs. When inspirations 
 occur in consequence of sudden emotions of the mind, they 
 are excited by impressions which the sensorium has re- 
 ceived from some external object ; but when they take 
 place in depressing passions of a continuous nature, they 
 are occasionally to be referred to congestion of blood in the 
 lungs, conjoined with the operation of the mental cause. 
 And I may here remark, that, although this preponder- 
 ance of the one act of respiration over the other is only 
 temporary, and their equilibrium is soon restored, yet the 
 irregularity is often of sufficient continuance to admit of 
 changes taking place fully calculated to account for the 
 morbid results attributed to them in this work. 
 
 In CCLVI. in speaking of the division of the par va- 
 gum in the different experiments performed to elucidate its 
 function, I omitted to state the situation in which the nerve 
 was divided. The division was generally made about 
 three-quarters of an inch below the glottis. 
 
APPENDIX. 3 
 
 In page 321, I have stated that the only function imme- 
 diately relieved by paracentesis abdominis, is that of res- 
 piration. Alvine evacuations are sometimes directly pro- 
 moted by the same means. The relief which is given to 
 the function of respiration is obvious, and seldom fails to 
 succeed the operation ; whereas, the intestines are only oc- 
 casionally acted upon in a manifest and beneficial manner 
 by the influence of the same cause. 
 
 In CCCCXXII. several theories have been proposed to 
 explain the various symptoms which are exhibited by those 
 who ascend very lofty mountains. SAUSSURE, who had 
 ascended Mont Blanc, and who had observed the different 
 phenomena of the system consequent on such an exertion, as 
 bleeding from the lungs, an unusually turgid and florid ap- 
 pearance of the body, and a distended state of the blood- 
 vessels, imagines that, owing to the great rarefaction of the 
 air, the usual quantity of oxygen is not inspired, and, con- 
 sequently, the blood does not undergo its usual changes in 
 the lungs. This opinion, as Dr CARSON justly remarks, 
 is incorrect,* as the symptoms are not such as characterize 
 the breathing of air in which there is a deficiency of oxy- 
 gen. There is one observation of SAUSSURE which shows 
 that the explanation which he proposes cannot be consider- 
 ed sound. He says, the difficulty of breathing and faint- 
 ness almost immediately ceased when the individual rested, 
 and as speedily commenced with the exertions which were 
 made to ascend. This phenomenon clearly proves that 
 the rarefaction of the air is not the only cause ; the indi- 
 vidual, when he rested, breathed with his ordinary free- 
 dom, but when muscular action was employed his respir- 
 ation became difficult. The condition of the atmosphere, 
 in both instances, is the same. 
 
 * An Enquiry into the Causes of the Motion of the Blood, p. 197. 
 
4 APPENDIX. 
 
 Dr CARSON endeavours to obviate the objections which 
 are made to the theory of SAUSSURE. He attempts to prove 
 that muscular exercise prevents the free return of blood to 
 the heart, and, therefore, when an individual rests in a 
 horizontal position, the blood is transmitted in its usual 
 way to the thorax, and consequently revives the sinking 
 powers of the system. This idea appears plausible, but, if 
 minutely examined, it can scarcely be allowed to be cor- 
 rect. Exercise alone seldom or never produces the peculiar 
 symptoms which are described by SAUSSURE and others 
 as occasioned by an ascent to Mont Blanc, and it has already 
 been observed, that the rarefaction of the air is alone insuf- 
 ficient to give rise to the same symptoms : it is, therefore, 
 manifest, that it is the combination of these two agents, co- 
 operating, as stated in the text, that tends to disturb the 
 whole of the sanguiferous system. 
 
 In page 39 I allude to a small machine which I con- 
 trived for the purpose of inflating rabbits with warm 
 air. It was constructed as follows : A common syringe, 
 of about two inches and a half long, was placed 
 in the centre of a small tin box, an inch and a half 
 deep. A brass tube, about the size of a large crow- 
 quill, was connected with the syringe, in order to ad- 
 mit the egress of air from, and ingress into it. There 
 was also another brass tube, about one-fourth of the dia- 
 meter of the preceding, two inches long, soldered to the 
 end of the syringe, which protruded without the box, 
 and which was connected at pleasure to the tube inserted 
 into the trachea of the animal. The box was placed upon 
 four tin legs of two inches and a half long, and was also 
 covered by a lid. The box was filled with water, and af- 
 terwards a spirit-lamp was placed underneath, which very 
 soon heated the water in contact with the syringe, and as 
 
APPENDIX. 
 
 the air, before it passes into the lungs of the rabbit, has to 
 traverse the syringe, it is necessarily warmed by the heat- 
 ed parietes. As it might have been stated that the air, 
 which was sent in, heated the animal to an inordinate extent, 
 I endeavoured to obviate such an objection by ascertain- 
 ing the temperature of the air during the whole process of 
 inflation. A wooden box, about the size of a walnut, was 
 made of two parts ; the bulb of a thermometer was placed 
 within, and when these parts were joined, the neck of the 
 instrument was firmly embraced. The box was after- 
 wards rendered perfectly air-tight by means of sealing- 
 wax. At each end of this box was a small brass tube, 
 one of which was connected, at pleasure, to the tube sol. 
 dered to the end of the syringe, and the other to the tube 
 inserted into the trachea of the animal. As the air passed 
 through the heated syringe into this box before it reach- 
 ed the lungs of the animal, the mercury was raised or de- 
 pressed according to the temperature of the medium to 
 which it was subjected. In this way it is easy to estimate 
 the temperature of the air which is sent in, and, by keep . 
 ing it many degrees beneath the heat of the system, we are 
 enabled to make the conditions of artificial inflation some- 
 what similar to those belonging to natural respiration. 
 Two wooden screens, separated by about four inches from 
 each other, intervened between the animal and tin box. 
 The machine was shown to Dr MILLIGAN, and he approv- 
 ed of the contrivance : It was also exhibited and explain- 
 ed by him to his Physiological Class in the Session of 
 1829- 
 
 THE END. 
 
 J-)hn Moir, Printer, Edinburgh.