1» IMAGE EVALUATION TEST TARGET (MT-3) // / L/ A% c^ &/ V 1.0 I.I f »^ ill 1.8 1-25 1.4 1.6 1 ^ g II \ u 1 .S^ V] > ' ^ V ^l'^^ '/ / /^ ^ Photographic Sciences Corporation 23 WEST MAIN STREET WEBSTER, N.Y. 1458^ (716) 872-4503 k''<^'' v ^\ %^ ^^ # m >^ CIHM/ICMH Microfiche Series. CIHM/ICMH Collection de microfiches. Canadian Institute for Historical Microreproductions / Institut canadien de microreproductions historiques Technical and Bibliographic Notes/Notes techniques et bibliographiques The Institute has attempted to obtain the best original copy available for filming. Features of this copy which may be bibliographically unique, which may alter any of the images in the reproduction, or which may significantly change the usual method of filming, are checked below. D Coloured covers/ Couverture de couleur □ Covers damaged/ Coi verture endommag^e Covers restored and/or laminated/ Couverture restaurie et/ou peliicuiie Cover title missing/ Le titre de couverture manque Coloured maps/ Cartes giographiques en cou'our Coloured inic (i.e. other than blue or black)/ Encre de couleur (i.e. autre que bleue ou noire) Coloured plates and/or illustrations/ Planches et/ou illustrations '>n couleur Bound with other material/ Reiii avec d'autres documents n n D Tight binding may cause shadows or distortion along interior margin/ La reiiure serr^e peut causer de I'ombre ou de la distortion le long de la marge int6rieure Blank leaves added during restoration may appear within the text. Whenever possible, these have been omitted from filming/ II se peut que certaines pages blanches ajoutdes iors d'une restauration apparaissent dans le texte, mais, iorsque cela 6tait possible, ces pages n'ont pas 6t6 filmies. Additional comments:/ Commentaires suppl6mentaires: L'Institut a microfilm^ le meilleur exemplaire qu'il lui a 6t6 possible de se procurer. Les details de cet exemplaire qui sont peut-Atre uniques du point de vue bibliographique, qui peuvent modifier une image reproduite, ou qui peuvent exiger une modification dans la mithode normale de filmage sont indiqu6s ci-dessouo. I I Coloured pages/ Pages de couleur Pages damaged/ Pages endommagdes Pages restored and/oi Pages restauries et/ou peliicul^es r~~| Pages damaged/ I I Pages restored and/or laminated/ rTyj ^ages discolourec ^^^^*««^ i^ at, Albumen. form use up "■"" ANIMALS DISTINCTIVE CUARACTERS OF ANIMALS AND PLANTS. (After Pye-Smith, modified.) 1. Chemical. Animals. Predominance of N compounds. Presence of luemordobiu. Plants. Predominance of Starchy compounds. Cellulose wall to each cell. Presence of chlorophyll. 2. Structural. Digestive cavity, ner- vous and muscular tissues. 3. Functional. Nutrition from inorganic food. Fixation of C. Nutrition from organic food only. Functions of relation predominant. Exceptions : 1. FiinrotocoQOU.s : The protoplasmic con- tents protrude through the cell-wall in the form of vibratile cilia. The cell- wall may disappear, and the protoplasm may undergo division ; it generally returns finally to the resting state. Like the other forms of plants already considered it hears drying without loss of vitality, and can be readily transported in this condition by winds. I. AMCEBA OR PROTEUS ANIMALCULE. A one-celled typical animal. It consists of a microscopic mass of jelly-like proto- plasm in which the following parts may be 4istinguish- ed : (a) Ectosarc firmer and clearer. (6) Endosarc more •fluid and granular, (c) Nucleus, (d) Nucleolus, (e) Contractile vacuole. (/) Paeudopodia. There is no ■cell-wall. Amoiba may exist in a less dilt'erentiated form. Tlie ama3ba reproduces by (a) fission, (]) gemmation. 14 All the activiti(« of amceba are permanently arrested at 0° C. and 4 5^ C. It has the following properties : It is Contractile. Irritable and automatic. Keceptive and assimilative. Metabolic and secretory. Respiratory, lieproductive. The above properties belong to protoplasm in general whether of plants or animals. It is clear that as a7P.wha can discharge all the functions of the highest animal it may be considered the simplest animal type. II. GExNERAL MORPHOLOGY. The units of which animals and plants are made up ai cells. A cell consists of a luall, contents', a nucleus and, sometimes a nucleolus. The nucleolus and cell-wall may be wantin^r. The anhial cell is generally without cell-\v\i,ll. The 7mcleus seems to determine largely the behavior of the cell, especially in reproduction. The ovain from the development of which the animal is derived is itself a cell. At one period of the development of the most com- plex animal forms tlie oroanisni is composed wholly of cells. Later in most animals there are, in addition to cells 15 tissues which are made up of cells, modified cells and '• ^' formed " material or secreted material, all derived from cells. t • Every cell arir^es from some antecedent cell by fission^ endogenous multiplication, gemmation^ etc. The simplest animals and plants as amceba and pro- ' tococcus are unizellular organisms. Some animals remain but little more than colonies of amceba?, as the sponges and some other crolenterates. The Infusoria may be regarded as modified amceba3 ; they are unicellular. Animals may be divided in accordance with their structure into two great groups : 1. Protozoa (Protista), one-celled organisms of which Amoeba, Faramoeciuni (slipper animalcule) and Vorticella (bell animalcule) are readily obtainable examples. " * 2. Metazoa, consisting of aggregations of cells and including all animals not belonging to the first group. A knowledge of the structure prevailing in the lower divisions of the group metazoa, may be derived from a study of changes taking place in the ovum of many animals. T'le ovum by segmentation divides into a number of cells which are finally grouped in a certain order, varying in different divisions of the Metazoa. Of spe- cial interest are the morula and the gastrida forms. In the morula the segments form a mulberry-like spherical mass. The cells nny so separate from one another as to give rise to a segmentation cavity within. 16 The cells may be arranged around the latter by invO' gination (inversion), or^by delamination giving rise to the gastrula. The segmentation cavity {archenteron) opens outward by the blastopore. The outer layer of cells is the epiblast ; the inner, the hypoblast. These, with the iatermediate memblad, constitute the ** germ-layers " of the vertebrate ovum. The gastrula form gives a good idea of the structure of hydra, the fresh- water polyp. The latter is composed of an outer layer of cells {ectoderm,) and inner layer {entoderm) which ^nclose a cavity answering to the stomach, etc. The tentacles may be regarded as tubular expansions of the sac. The mouth corresponds to the blastopore of the gastrula form. Hydra reproduces by gemmation, but in the summer season testes form at the bases of the tentacles and ovaries at the attached end of the animal. A polyp may be regarde I as a colony of amaiboe, modified, and arranged as a double- walled sac. Such structure is typical of the whole group coelente- rata (sponges, jelly fishes, hydroids, corals, etc.) If a hydra be divided into segments, each of the latter can develop into an entire animal. The neuro-muscidar cells and the urticating capsules (thread cells, nematocysts) are of special interest. 11. Physiological. Introductory. Physiology is the science which treats of the func- tions of living organisms. Vitality and function are the resultant of certain forces, chemical and physical. Life may be regarded as the sum or resultant of the energies of living matter. Energy may be potential (latent) or kinetic. Kinetic energy is evidenced in motion, whether of molecules and atoms or of masses. One kind of energy is representable and exchangeable into another ; but energy or force cannot be annihilated. Consumption of energy ; correlation of forces. Vital energy may be transformed chemical energy, latent or potential in food and rendered kinetic in the form of heat and motion. Physiology is advanced only by observation and •experiment. It is an experimental science. "Experimental" is often used in a sense opposed to " chemical " physiology. Modern physiology aims at ascertaining the chemistry and physics o( protoplasm. As a matter of fact, physiology has, hitherto, inves- tigated the functions of certain woU-known mammals B 18 (rabbit, dog, cat, and, to u less extent, the horse and a few others), chiefly. Human physiology has been studied in a few cases of traumatic listulie, &c. ; but a great part of the so- called " 'luman " physiology is the product of inference and deduction from the results obtained by the experi- mental study of the lower animals and from clinical and pathological investigation. The latter must always be received with great caution in the realm of physio- logy. Its chief value lies in its nuggestiveness. The physiology of the invertebrates, ami in great part of tlie lower vertebrates, is yet to be wrought out ; but till such is acconijilished there can be no complete human physiology. In the advancement of the latter branch of the science much may be done by the individual in the form of observation and experiment on himself. Modern physiology and psychology are closely related. It will appear from the foregoing sections that the study of physiology implies the application of anatomy, chemistry and physics at every step. The tissues are susceptible of the following i:)hjsiolo- gical division : Contractile. Irritable and automatic. Secretory or excretory. Metabolic. Reproductive. Indifferent, mechanical or storage. Ill Chemical Constitution of the Body. Such food as supplies energy directly must contain carbon compounds. Living matter or protoplasm always contains nitroge- nous carbon compounds. In consequence C, H, 0, N, are the elements found in greatest abundance in the body. The elements S & P are associated with the nitroge- nous car])on compounds ; they alio form metallic sul- phates and phosphates. CI and F form salts with the alkaline metals Na, K and the earthy metals Ca and Mg. Fe is found in hcemoglohin and its derivativea. Protoplasm, when submitted to chemical examination, is killed. It is then found to consist of proteids, fats, carbohydrates, salines and extractives. It is probable that when living it has a ve^y complex molecule consisting of C, H, 0, N, S and P chiefly. riiOXIMATE PRINCIPLES. I Proteids. (a) Nitrogeuoud. j ^.^^^^j^ crystalline bodiefl. 1. Organic 2. Inorganii (b) yon-nitrogenou8. \ f Mineral salts. \ Water. Carbohydrates. Fats. 20 Salts. — In general the salts of sodium are more characteristic of animal tissues and those of jw^as- sium of vcffetable tissues. Na CI is more abundant in the fluids of animals ; K and ])hosphates more aliundant in the tissues. Earthy salts are most al)undant in the harder tissues. The salts are ])ro])aljly not' much, if at all, changed in their passage through the body. In some cases there is a change from acid to neutral or alkaline. The salts are essential to preserve the b.ilance of the nutritive processes. Their absence leads to disease, e.g., scurvy. OEriERAL CHARACTERISTICS OP PROTEIDS. They are the chief constituents of most living tissues, including blood and lymph. Tlte molecule consists of a great number of atoms (complex constitution), and is formed of the elements C, H, N. 0, S and V All proteids are amorphous. All are non-diffusible, the 'peptones excepted. Tliey are soluble in strong acids and alkalies, with change of properties or constitution. In general they are coagulated by alcohol, ether and heating. Coagulated proteids are coluble only in strong acids and alkalies. 21 (ftaaaifiration and Dlatlngidshing CJiaractera of Proteiih. 1. Native alhxLmina : serum albumin; egg albumin; soluble in water. 2. Derived Albumins (albwninatea): Acid and alkali albumin; casein; soluble in dilute acids and alkalies, insoluble in water. Not precipitated by boil- ing. 3. Olobulins: globulin (globin) ; paraglobulin; myosin ; fibrinogen. Soluble in dilute saline solutions and precipitated by stronger saline solutions. 4. Peptones: soluble in water; diffusible through animal membranes ; not ^precipitated by acids, alkalies" or heat. Derived from the digestion (peptic, pancreatic) of all proteids. 5. Fibrin: insoluble in water and dilute saline solu- tions. Soluble, but not readily, in strong saline solutions and in dilute acids and alkahes. CERTAIN NON-CRYSTALLINE BODIES. The following bodies are allied to proteids, but are not the equivalents of the latter in the food. They art. all composed of C, H, N, 0. Chondrin, gelatin, keratin have in addition 8. Chondrin: the organic basis of cartilage. Its solu- tions set into a firm jelly on cooling. Gelatin : the organic basis of bone, teeth, tendon, etc. Its solutions set (glue) on coolin< 22 Elaaiin : the basis of elastic tissue. Its solutions do not set jelly-likv ''gelatinize.) Mucin: from the secretion of mucous numbranes; precipitated by acetic acid and insoluble in excess. Keratin: derived from hair, nails, epidermis, horn, feathers. Highly insoluble. Nttdein: derived from the nuclei of cells. Not digested by pepsin ; cnitains P but no S. THE FATS, The fats are hydrocarbons ; are less oxidised than the carbohydrates ; are intlammable ; possess latent energy in a liigh degree. Chemically, the neutral fats are glycerides or ethers of the fatty acids, i.e., the acid radicles of the fatty acids of the oleic and acetic series replace the exchange able atoms of H in the triatomic alcohol glycerine, e.g. r^^ ' r» 1 •*.• 4 -i Glycerine tvi-palmitate Glycerme. 1 almitic Acid. -^ t^ , or I alniitin. c OH HO.OC.C.j H,, r O.CO.C,,H3, CjHs I O H + HO.OC.C,, H3, = C3 H J O.CO.C.iH,, + 3Iiyo (oh HO.OC.C,, H3, "(.0.00.0,^13, A soap is formed by tlie action of caustic alkalies on fats, e.g. Tripalmitin. Potassium Palmitate. (CSJ0,,.3(K0H),3{(^..-».0)0|.C»H.|0^ 23 The soap may he decomposed hy a strong acid into a Eitty acid and glycerine, e.g. C,» H„. C O, K 4- H CI « C„ H„. CO, 11 + K CI. . rotasiium Palniitate. Palmitic Acid. The/.(^5 are insolulde in water, l>iit .soluljle in hot alcohol, ether, chloroform, etc. The alkaline soaps are soluble in water. Most animal fats are mixtures of several kinds in varying proportion; hence the molting point for tlie fat of each species of animal is different. PICULIAK FATS. Lecithin, Protucion, Cerebri n : They consist of C, H, N, 0, and the two first of P in addition. They occur in the nervons tissues. CARBOHVDRATKS. 'General formula Cm (II, 0)n. 1. TfiE Sugars: Dextrose c m-am su'-^ar C. H, O + H, readily undergoes alcoliol'"c fermentation ; less readily lactic fermentation. Lachse raillc sugar C,, II,, 0„ -f H, ; susceptible •of the lactic acid fermentation. Inosit or muscle sug ir C , H,, > -f- 2 H, ; capable of the lactic fermentation. Maltose C,, H,, 0„ + H. 0, capable of the alcoholic fermentation. Tlie chief sugar of the digestive process. All the above are much less sweet and soluble than ordinary cane sugar. 2. The Starches: . Qlycogen Cc H,o Oj convertible into dextrose. Occurs abundantly in many ftetal tissues and in the liver, especially of the adult animal. Dextrin Co H,o 0^, convertible into dextrose. Soluble in water ; intermediate between starch and dextrose ; a product of digestion. Pathological: grape sugar occurs in the urine la Diabetes mellitus. Certain substances formed within the body may be regarded as, chiefly, waste-products, the result of meta- bolism or tissue changes. They are divisible into nitrogenous metabolites and non-nitrogenous metabolites. Nitrogenous Metabolites : 1. Urea, uric acid an 1 compounds, kreatinin, xanthin, hypoxanthin (sarkin), hippuric acid, all occurring in v.rine. 2. Leucin, tyrosin, taurocholic and glycocholic acids, which occur in the digestive tract. 3. Kreatin, constantly found in muscle ; and a few others of less constant occurrence. The above consists of C, H, N, 0. Taurocholic acid contains also S. The molecule in most instances is complex. 25 Non-Nitrogenous MetabiJites. These occur in small quantity, and some of them are secreted in an altered form. They include lactic and sarcolactic acid, oxalic acid, succinic acid, etc. Demonstration : The properties of the bodies coil- sidered in this chapter. IV. Blood and Lymph. BLOOD. Blood with Lymph constitutes the great ''internal medium" of the tissues. (liernard). Blood is morpholoiLjicjilly a tUsue in vvhicli th. isma represents the matrix and the corpuscles tuv. cell elements. Living blood in tlie vessels consir^cs of plasma and corpuscles; blood when shed rapidly dies resulting in coagulation. Histological : 1. Colorless corpuscles : relative num- bers, form, size, etc. They constitute the sole morphological element in the blood of most invertebrates. 2. lied Corpuscles : size, shape, &c., in the different groups of vertebrates. Their peculiarities in the mammalia. The red corpuscles of man. Nucleated in the fcx^tus. Distinction of stroma and hoimoglohin. The colorless corpuscles are morphologically and physiologically amoeboid cells (amoebae.) 27 Physiological : Bluud within an arteriole ; within a caj)illary. Blood as it issues from a divided artery; a divided vein. Phenomenon of Coagulation : As seen in blood shed into a vessel. Stages: gelatinous stage; solid clot (coaguluni) ; cupping ; expression of serum. Coagulation of a drop of freslily drawn blood, under the microscoj)e ; fibrin threads ; rouleaux. Clotting in a capillary tube. Whipping or defibrinization of blood. Physical condition of blood : (a) Before coagulation as ( Plasma. in a blood vessel ; 1 Corpuscles. ^_ . „ , . ^ c Fibrin. (o) After clotting : Clot. \ , , , ' ° ( Corpuscles. Serum. / \ -Tk r-i • ^ 1 I I i ( Corpuscles. (c) Deiibriiiated blood : < ,, ^ ' ( Serum. Theories of Coagidation : 1. Coagulation is due to the action of a fibrin fer- ment on i)araglobulin (tibrinoplastin) and fibrinogen (A. Schmidt). Ferments are classified as : 1 Organized, as yeast. 2. Unorganized, such as occur in the animal body. They are characterized by the following : (a) small amount required for action ; (b) are not destroyed by the process ; (c) efficient only within narrow limits of temperature ; {(^) they act only in a medium of a definite chemical reaction. 28 2. Coagulation is due to the action of a fibrin ferment on fibrinogen alone (Hanimarsten). Recent eonfirmation of the latter by the study of the blood of the tortoise (Howell). Bearing ujton the subject of coagulation of the investigations of Wooldridge. The study of morphological elements of the blood other than the red and white corpuscles (Bizzuzero, Osier, Hay em, Kemp). Comparative: Investigation of the blood of Crustacea, etc. (Halliburton, Howell). It follows that fibrin does not exist preformed in liv- ing blood. Appearances of the clot under different circumstances. Variation in color ; " the buffy coat. " Importance of coagulation in accidents ; surgical oper- ations, etc. Paraglobin found in serum : how separated. •.» Fibrinogen obtained from transudation fluids. Method of preparation. Denis' plasmine ; preparation. Fibrin ferment ; preparation. Prevention of coagulation by cold. Settling of th& corpuscles, (horse's blood). Coagulation of the supernatant plasma on raising the temperature. Coagulation by mixing serum and hydrocele fluid. Coagulation in the heart and vessels of a dying ani- mal. 29 Coagulation on foreign bodies jilaced in the vessels. Why blood does not coagulate in the living body. Fluidity of blood after death. The influence of the living tissue of the internal coat of the blood vessels ; effect of disease and injury of the same. ' The influence of surface on coagulation. The influence of the constant interchange in nutrition. Circumstances favoring coagulation. >^ o '< . products of digestion or Xle ' " '"'"''"'' "'"^ ""« ^c«W2/r (Gaskell ; MillsJ ; •of Menohra7U'hu» ( Mills) ; of the cuttle-fwh Hansom. /Ka^^^^Jl^ These investigations have greatly modified our con- •oeptions of spontaneous rhythm ; of the nature of the heart heat as a muscular act ; of the nervous supply of the heart. Especially has it been shown that the var/us has functions much more varied and important than was formerly supposed. Brief summary of the main conclusions. DEiMONSTUATIONS. Flow irom an artery and vein compared. The action of the valves in the dead heart of a mammal. The heart of the mammal i?i situ : chest opened. Auscultation of sounds before «nd after opening chest ; palpation of ventricles in action. Isolated frog's heart : The Stannius' ligature. Arrest by electrical stimulation of sino-auricular junction. Electrical stimulation of the isolated ventricle ; !' stair-case " of beats. £ 66 Pulsating sections of tne heart of the frog. Variations in the action of the heart with altered temperature ; jjilocarpin ; at'opin, &c., &c. Behaviour of the ventricle of the frog's heart when supplied with nutriment. Behaviour with altered pressure. The work of the heart. Inhibition of vagus effects by otropin. Nerve effects : Section of one and of both pneumogastric nerves of the dog. Vagal inhibition in the mammal and frog. Keflex Miliibitiou in the frog (Goltz' experiment). Vagus and accelerator effects on the heart of the mammal. Stimulation of the accelerator. Blood pressure : Comparison of the arterial pressure in two large arteries of the same mammal. Comparison of blood pressure in an artery and a vein. Blood pressure experiments without the use of the kymograph. Blood presmre experiments with use of kymograph; manometer and tracings. Effects of: Stimulation of peripheral end of vagus. Stimulation of central end of depressor. Section of spinal cord. 67 Stimulation of peripheral end of spinal cord. Compression of the aorta. Local blood iircssure : Effect on vessels of rabbit's ear of : Section of the cervical sympathetic. Stimulation of its peripheral end. Stimulation of the central end of the auricularls nnafjnvs. The sphygmogiaph : tracings. Various points onnected with blood-pressure, the heart, the pulse, etc., by simple apparatus improviged for the occasion. Observation by the student in his own person of : pulse ; cardiac impulse ; study of the heart sounds with bin- aural stethoscope ; venous flow, etc., etc. THE LYMIMIATIC CIRCULATION. Anatomical and physiological : Origin and structure of lymph capillaries ; resem- blances of lym})hatic3 to veins. Laciuiw or lymphatic spaces. Principal points of junction of the lymphatics with the great veins. Lymphatic glands : the regenerators of the leucocytes ; the thoracic duct; main channel of commimication with the digestive tract. Tiie lymph hearts of the frog, etc. Lymph, chyle and blood compared. iii lii! 68 Lymph is the immediate source of nourishment of the tissues which are bathed in it. It is also the first recipient of the waste products of tissue metabolism. The valves of lymphatics. The onward flow of lymph is facilitated by : 1. Muscular exercise. 2. Aspirating influence of the great veins into which the main lymphatic trunks empty. I VIIL Eespiration. The purpose of respiration : removal of the waste* products of tissue metabolism ; provision of oxygen for the tissues. These ends are finally effected by diffusion. The various mechanisms of respiration are subservient to the process of diffusion. Evolution of Respiration: 1. Respiration by thft general surface of the body as in Protozoa. 2. By- the integument as in Amphibia. 3. Folded surfaces, external to the body, suitable for respiration in a liquid medium as by the (jilU of Fishes^ and branchiae of various invertebrates. 4. (a) Open tubes or trachece (insects). \ Within the {b) Folded surfaces or lungs. ) Ijody ; Adapted for respiration in a gaseous medium as in land vertebrates and all ivarm -blooded animals. The respiratory organs of the mammal are outgrowths, from the digestive tract (fore-gut) of the embryo. ANATOMICAL : External respiratory openings (nares) ; trachea and bronchi ; " bronchial tree " ; folded memljrane lined with flat epithelium (I'ulmonary cells). ■'( - ■ r-T-r- 70 A hronclms : muscle ; cartilaginous rings (imperfect) ; mucous membrane with its mucous glands and ciliated epithelium. The lungs : Subdivisions ; alveolar passages (infun- dibula) ; alveoli, air cells or air vesicles ; flat lining epithelium ; capillary circulation ; muscular and elastic tissue. The relations of the pleura (closed sac) to lungs, chest Walls, diaphragm. The relation of lungs to chest walls, heart and great Vessels diaphragm. CorapaTative : The lung in the amphibian, reptile, bird ; air bladder of fishes, etc. THE MECHANICS OF RESPIRATION : RESPIRATORY MOVEMENTS. Marked elasticity of the lungs ; made up in great part of elastic tissue. Never fully distended in the thorax. The elasticity of the human lungs may be represented by a manometric column of 5 millimetres of mercury. How measured. Degree of pulmonary distention in ordinary inspira- tion, forced inspiration, ordinary expiration, forced ex- piration, and the death position compared. Friction, how lessened. In all the movements of the chest walls and diaph- ragm the lungs follow and are closely applied to their surfaces. 71 Why the lungs expand in insj iration (atmospheric pressure) and diminish in expiration (elasticity). Inspiration is the adioe phase of respiration ; expira- tion the passive one. Eecoil of chest walls. Modifications of the shape and size of the chest dur- ing respiration. The diameters of the thorax : vortical, transverse, antero-posterior. Muscular inechanisms hij which they are made to vary ; muscular ruechanics : Muscles of fixation ; of elevation (and depression) ; of aversion ; ordinary and extraordinary. Co-ordination of muscular action in an ordinary inspir- atory act. rhysi(jlogical (functional; division of muscles accord- ing to the character of the respiratory act. The scaleni, the intercostals, the diaphragm. The diaphragm is tlic most important re-[ iratory muscle. Impc»rtance of the abdominal muscles in labored respiration, and various special modifications of the respiratory act associated with other functions (deficcation parturition, vomiting, sneezing, coughing, etc.) The costal movements. The lower ribs in forced inspiration. Types of reHplratioii in the human subject : Thoracic, abdominal, (costo-superior, costo -inferior) 72 Thoracic and abdominal or diaphragmatic respiration^ in other vertebrates. Facial and laryngeal movements in man and other animals. Friction, how lessened. Respiratory rythm. Inspiration to expiration as 10 to 12. Curve of thoracic respiratory movements. (Marey's Pneumatograph). " Cardiac respiration '' of hybernating animals. Modified respiratory acts : Sneezing, coughing, laughing, crying, hiccough, etc. THE VOLUME OF AIR ; ITS VARIATIONS. A certain portion of the air of the lungs is moved by diffusion only. The moving column of air in ordinary respiration is of small volume. Tabulation^of volumes : Stationary air C residual 100 cubic inches. 200 cubic inches ( supplemental 100 cubic inches. Tidal air. 30 cubic inches.. Complemental air 98 cubic inches. Total capacity of lungs. 328 cubic inches. Vital capacity ; modifying causes. Post mortem " air ; " tissue '* air of collapsed lung. The quantity of air requisite for daily consumption.. Method of computation. I , 78 CHANGES OF AIR IN RESPIRATION. 1. Difference in temperature of the expired and inspired air. Heat is thus lost to the body to the extent of 20 per cent. : (a) by warming the air (5 per cent) ; (b) by evaporating the water given off witli the expired air (15 per cent). Variations in the above. 2. Difference in quantity of moisture. Expired air is almost saturated. 3. Difference in chemical composition. The atmosphere is composed of oxygen " dissolved in " nitrogen. Analysis of the air of respiration ; Oxygen. .Nitrogen. ^-^^-^^^^ Air of inspiration 20.810 79.150 .040 Air of expiration 16.033 79.557 4..380 Total quantity of consumed, and C 0^ exhaled, in 24 hours. Respiratory relations of animals and plants. Proportion in volume of the inspired and expired air.. Real loss in volume by inspiration. " Respiratory quotient " ^- (^^,) =0.90G. Effete organic matter and volatile organic bodies of the expired air. Ventilation. C O2 standard of impurity. I 'I C lass IJiccU Ion of r/a.-ics in relation to the Respirator ij /unction : 1. Indifrercnt : H, N. 2. IiTe.si)irable (spasm) ; CI, N H^, &c. 3. Poisonous : (a) Narcotic C 0^, N^ 0, Ozone. (b) Kcdiicing H, S, P H-, As H,, Sb II,, C N, C 0. NO. THE CHF.MISTltY OF RE.sriR.\TION. External (pulmonary) and internal (tissue) respir- ation : Difference in color between arterial and venous blood. Ordinary venous blood and the blood of asphyxia compared. Average composition of the gases derived from blood : CO, N Arterial blood 2 40 1-2 Venous blood 8-12 46 1-2 From 100 volumes of blood 60 volumes of gas may be obtained. Apparatus for the investigation of the blood gases. The laws governing the absorption of gases by ordin- ary liquids compared with those regulating the corres- ponding a))sorption by blood. Law o[ partial pressure. 76 Interchange of gases according to the taufiio)!. CO, 27 27.44 A alveolar lueinbrane. V rmlial ]»ie6.sure of air in alveoli of luug. Tension of gases in ven- ous bh)0(l of lun«r. 41 22 CO, U The oxygen of blood is almost all combined with the coloring matter of the red corpuscles, hiemoglobiu. The C O. is chiefly in loose chemical combination with certain constituents of the plasma. The nature of the union biitween the oxygen and oxyhienioglobin is one of ** loose cliemical combination." Chemical constitutioti of hiemoglobiu ; C, H, N, Fe, S, 0, in complex combination. Intra-molecular ; loosely combined (J. There is a considerable quantity of iron in the molecule (0.4 per cent). This Fe is replaced by other metals in some animals ; in which also the plasnvx and not the corpuscles seems to function as the respiratory part of the blood (Crusta- ceans). In some animals Fe is associated with the plasma (annelids) . Hiemoglobin may be decomposed into a globulin and hcBmatin ; the latter contains Fe but no S. Hiematoin (^Preyer) is luematin free from Fe. ■!^l 76 H.Tmin is Hydrochlorate of ha'raatin. Crystals of hiumin (Toichinaun's crystals). Crystals of Imano^'lobiii. Importance of blood crystals in the recognition of altered blood ; distingnisliing blood and solutions of lux'moglobin from otlier red Huids, etc. HiL'Uiatoidin (bilirubin) : crystals of old blood clots. Composed of C, H, N, 0. — Ha'Uioglobin. C O — Hiemoglobin. N — Iliemoglobin. Poisoning by N O, C 0, C N-hjemoglobin. Arterial blood is normally almost or quite saturated! with oxygen. Venous blood always (except in fatal asphyxia) con- tains some oxyluemoglobin. Tke oxidative processes of the body occur in the tissues and not in the blood. Illustrated by the study of muscle. During the day time and during exercise, more oxygen is given off as C O^, than is absorbed. The reverse holds during the night and during rest. The same laws hold for the interchange of gases |i between the blood and the tissues as between the blood and the pulmonary air. Relation of blood pigments to the other pigments of the body. 77 SPECTRUM ANALYSIS OF BLOOD rir.MENTS. Spectrum appearances of a solution of: 1. Oxyhiemoglobin of diflerent de^Tues of strengtli. Disappearance of one band. 2. Hiemoglobin (reduced hiBinoglobin). How distinguished from a concentrated solution of '0 — hii'nioglobin. 3. C — luenioglobin (carbonic oxide hiemoglobiu). Its permanancy and irreducibility : will resist putre- faction (Hopj)e-Seyler ; Landois). 4. Acid and alkaline luematin. 5. Hiemachromogen (reduced hicmatin). 6. Hieraatoporphyrin, 7. Methiemoglobiu (spectrum like that of acid hfematin). Metfuemoglobin contains more oxygen than oxyhai- moglobin (IloppeSeyler). Oxyhiemoglobin changed to methjemoglobin when discharged into urine, etc. Kecent spectroscopic investigations (MacMunn). INFLUENCE OF RESPIRATION ON THE CIRCULATION. Aspirating effect of the inspiratory movements. jRetardation of venous flow during expiration. The negative effect on the great arterial trunks of the thorax. Comparison of the curve of b!o3d pressure with the curve of intra-thoracic pressure. if 78 Cfra])hic' r«.!|»re.sc'iitiitiou of clmuges in tho pulse-wave. Triiulic-IIt'iing curvt'.s. Theso suem to l)u owing to iliythiiiic variations in tho action of tho vaso-niotor centre. The respiratory variations of blood-pressure as a whole must be referred to mechanical rather than to nervous causes. THE NKUVOUS MECHANISM OF RESPIKATION'. Eespiration is involuntary ; it nuiy bo ^modified but not wholly arrested by the will. Anatomically the mechanism concurned in respiration consists as in other rellex acts of : {a) Ajferent nerves, especially the vagus. (6) Eferott nerves, supplying the various respiratory muscles. (c) A respiratory centre in the medulla. There are j|)r(jbably otlier suljonliuate centres in the spinal cord. The i)hrenic arising from the cervical spinal cord is the great motor nerve of the dijiphragni. The resi)irat()ry centre or nuiwl vU(d (Flourens) lies below the vaso-motor centre and above the calamus scrijHorius. Experimental : (a) Complete cross section of the spinal cord in dif- ferent regions. (b) Division of a costal nerve : paralysis of its muscle. (c) Division of one and of both phrenic nerves ; para- lysis of diapliragu]. 79 ((/) Division of one and of both \i\<:'i : modi lied res- piratory nioveinents ; deeper anil slower respiration; marked pause. Stbniikitionof: (n) central end of divided vagus; the other nerve being also cut : inspiratory tetanus. (6) Central end of superior laryngeal: exiiiratory tetanus. Division of the medulla in the middle line; f/eminal character of centre. Ina'cascd action of the respiratory centre : (a) After division of the s]>inalct»rd below the med- ulla oblttngata with section of both vagi. ( b) After ligature of the blood vessels of the neck. The increased action is due chiefly to diminution of the supply of oxygen to the centre. The action of drugs on the centre through the blood. Eflect of emotions; of cold (water) suddenly applied to the skin. Surnmary of Inferencts from the ahove experiments : Impulses which tend to modify the discharges from the res})iratory centre are constantly proceeding to it along the spinal cord, chiefly ; but also from the cere- brum ; either originating j rimarily in these centres or proceeding to them by various nerves, especially the pneumogastric. The costal and the j'lireuic are the most important 1^ motor nerves of ordinary inspiration. so The pneumogastric is the path of impulses tending to quicken the respiratory movements and the superior laryngeal that of tliose of an opposite character. The respiratory centre is geminal. It is essentially automatic in action ; but its action is constantly being modified by afferent impulses. It is possible that the movements of the lungs them- selves may furnish stimuli exciting to action of the centre. The action of the centre is detei mined by the quality of the blood supplying it ; venous blood being stimulat- ing (C 0,). The nature of dyspnoea apnoea and eupnoea com- pared with special reference to the respiratory centre. The rhythmic action of the respiratory centre is pro- bably the resultant of two forces, ore rep'sting, the other exciting to nervous discharges. The action of the centre may furnish its own stimuli in the form of waste-products. The nerves are at once the conductors of modifying impulses, and the avenues along .vhich the discharges of the centre travel to the muscles. The resistance theory of Rosenthal. The double character of the centre : inspiratorv and expiratory. The phenomena of Asphyxia ; stages and duration ; character of the blood. Post mortem appearaaces of the heart and blood- vessels. n 81 Cheyne-Stokes respiration. Eespiratory sounds. Eficd on the respiration of changes of pressure of the air breathed. 1. Gradual diminution of pressure : dyspnoea owing to diminution of 0. 2. Sudden diminution of pressure : liberation of gas .', causing mechanical interference with the circulation. 3. Increase of pressure : when of a certain degree (4 atmospheres of 0) leading to diminished oxidation with syn.ptoms of asjjhyxia. Artificial respiration. ltes})iration of hyl)ernating animals. ABNORMAL : Dysp -icea of asthma ; feeble respiration of phthisis ; hampering efYect of pleuritic adhesions. Pneumothorax ; pleuritic eftusions. Effects of altered pressure : ascent in balloons ; scaling mountains ; de."cending shafts of mines. Asphyxia : drowning, hanging, clioking ; poisoning by carbonic oxide. DEMONSTRATIONS : Anatomical examination of gilh of oyster, crab, fish and menobranchus; res])iratory sacs oi menobranchua ; air bladder of fish ; lungs of frog, snake, bird, mammal. Demonstration of the gaseous interchange in respira- tion. F 82 Itespiratory schema. IMeasuremeiit by the mercurial manometer of the relative pressure in inspiration and exi)iration, ordinary anbasenieut membrane with covering cells. V Secretion The simplest gland is uniceUular. The most complicate I glau 1 is but an aggregation of cells, with special arrangements for holding them together, tor blood supply, and for removal of their secretion. The simplest form of gland in the mammal is the tubular ; but there are secreting memhianes. Extension of surftice provided by increasing com- plexity of structure. In digestion the secretions act on food. 84 Characteristics of a food. Food of animals and plants compared. The food of animals must be organic together with water and salts. The greater part is not only organic but organized. The purpose of a food : to reconstruct tissues and restore energy. Energy is derived chiefly from oxidizable compounds of carbon and hydrogen with or without nitrogen. Certain substances important for the welfare of the organization seem to be^ chiefly rejulators of nutritive processes. "Adjuvants": relishes, condiments, stimulants. CLASSIFICATION OF FOOD-STUFFS (iNGESTA.) T 1 i ; ater. r q i 1 1 i °' ( Mineral salts. -< j , ^\ < Incombustible. r« , ^j-. ( Albumins. 2 ( Nitrogenous. < *ii • • i \ ^ r. ■ I XT V , i Albuniinoids.r, I a- Organic. -( JNon-nitro- ( .^ \ ^ i , . i>uoar, ■<. c '^ ] ) Carbuhydiates, ( r. ° / 1 ^ (, genous. "i ] btarches, j ST. ( Fat. ^ etc. I i^ Ege.bta represent altered food-products, useless or harmful to the economy. The principal part of nitrogenous foods reappears in the excreta as crystalline nitrogenous bodies ; that of the- hydrocarbons and carbohydrates as carbon dioxide and water. Importance of cooking. Typical food : milk (and eggs). t-r^a., , 85 DEMONSTRATIONS. The principal properties and reactions of the above food -stuffs. DIGESTION IN THE MOUTH. Anatomical and physiological : The teeth of different groups of animals compared. Itelation of structure to function. The tongue; its function in different classes of animals. Tentacles in the invertebrates. Minute anatomy of : Teeth : enamel ; dentine ; crasta petrosa ; nerve and vascular supjjly. Tongue : arrangement of muscles ; nerve-endings. Mucoids glands : abundant distribution in the buccal and pharyngeal cavities. Food in the mouth is comminuted and submitted to the action of saliva. Mastication : muscles concerned. SALIVARY GLANDS. Mucous and serous glands : resemblance in minute structure to the Pancreas. Belong to the class racemose. Crescents of Gianuzzi ; composed of marginal cells. 8G SALIVA. Mixed saliva found in the mouth. Secretion of wro us and mucous ghmds compared. Morplioh)gical elements of saliva. Chemical constitution. Bodies peculiar to saliva : (a) Ptycdin, nitrogenous but not a proteid; (J)) Pofcuslum sulphocyanide. Ptyalin is an unorganized ferment (see page 27). DlyeMive action of saliva : Ite((uires an alkaline medium. Influence of temperature. Ptyalin l)ears a somewliat higli temperature, but not that of lK)iling water. Eai)id acti(jn of i)tyalin. The sole digestive action of saliva is on the starchy elements of food (diastatic action). Starcli converted into sugar : maltose and dextrose, chiefly the former. Dextrin and acroodextrine. NEllVOU.S MHCIIAXISM OF SALIVARY SECUETION. The nerve supply of the submaxillary gland : sympa- thetic and cerebral. Experimental ficts : Stimulation of the peripheral end of the chorda iym- 2XUU sup])lying the submaxillary gland) of the dog is followed by : (a) Dilation of the blood vessels of gland ; there may be a venous pulse. s\ (h) Copious flow of saliva. (c) This secretion will take place in a decapitated animal. (d) Secretion follows stimulation of the lingual nerve or of the tongue (rotlex act). (e) After administration of atropin secretion does not take place, hut the vessels dilate as he fore. (/) Secretion will tak(^ place when the pressure in the duct is greater than tliat of the blood in the artery of the gland or even the carotid. Conclusio7is : 1. The Chorda Tympani is the secretory nerve of tlio gland; secretion is aMOuipanled by vascular dilation {a and h). 2. S.'cretion is not purely a process of filtration (r, cand/). 3. Secretion may Vje excited rellexly {d). Stimulation of the c.u'vical sympatlietic in the dog gives ris(; to vascular constriction and scanty How of viscid saliva ; the exaet opposite of the results on stimulating the chorda. Diagram of the nervous mcfdianism of salivary secre- tion. The '* paralytic " secretion of saliva. The secreting centre. Influence of hiijher centres over it. 88 The Gland compared histologically before and after stimulation : Behaviour towards reagents ; alteration in lumen ; alteration in size of cells ; position of nucleus ; degree of granulation, etc. The nervou*} m)chanisni of salivary secretion was worked out by Claude Bernard. Constructive (anabolic) and destructive (Jcata- holic) action in the gland protoplasm ; mothcr-fermoit, pro-ferment, zymogen. DEGLUTITION. The bolus of food ; part taken by tongue, cheeks, &c. Swallowing may be partly voluntary and partly invol- untary ; is essentially involuntary. Stages; muscular mechanism. Protection of the respiratory openings. Is a reflex act ; centre in the medulla. The ae^ophajiis : circular and longitudinal muscular fibres ; voluntary and involuntary muscle cells ; mucous glands. Peristaltic action. Relaxation of cardiac sphincter. Swallowing as witnessed in the ruminants. Force exerted by the gullet in swallowing (Mosso). 89 DIGESTION IN THE STOMACH. ANATOMICAL AND PHVSIOLOGICAL : The stomach in the frog ; carnivore ; ruminant ; etc., compared. The human stomach : furm, ruUitions, nervoua and vascular supi)ly. Fundus; cardiac and pyloric ends. Walls of empty stomach (and gullet) collapse. Folds of mucous memlnane (nujie) of the collapsed stomach. Coats of the stomach. Arrangement of the muscular fibres. Sphincters : Cardiac and pyloric (valve). Nerves : vagus ; splanchnic. Nerve cells. Gastric glands : kinds ; differences. The cells of the glands, (a) central cells chief cells, secrete pepsin and rennet. (6) Superadded, parietal or oxyntic cells. Glands of the pyloric end have only central cells. Transition glands of i\\Q pylorus. Arteries, after distril)Ution in the areolar coat, break up as capillaries around the bases of the glands. THE GASTRIC SECRETION. How obtained. Fistul*. Flow only during digestion. Physical and chemical properties of the secretion. The ferment is pepsin. 90 The acid roiictioii is owing to II CI — iiresent to the extt3iit of 0. 12 Iter cunt. Thu llClislVee. Tlio pvesunco of l)Utyi'i(', luetic iind otlier acids is tracealilc to ffrniuiitution. (,)u;uititv of 'Mstric juice: variations (liirin<' diifostion. Dljentlce action. The activity of gastric juice is exerted only on proteids. Action owing to pcp'^lii : ellicieut only in an acid medium. Auxiliary to pancreatic digestiiMi. The mucus of the stomach seems to contain a fer- ment capable of converting cane-sugar into dextrose. C„ IL, ()„ + II, = 2 (C\, II,, 0,) Solution of salts in the fl CI of the secretion. Pepsi iKxjcti : the z)j)HOf)eii of gastric juice. Functions of the dirferont kinds of cells of the gastric glands. Iiennet: acts on casein as a curdling ferment. Has a curdling power inile[)endently of the acid of the stomach. The conversion of [iroteids into Xieptones which are soluble and diffusible. Other properties of pei)tones : soluble in water ; not precipitated by l)oiling ; give the reaction of proteids, etc. Formation oi parapeptone (acid albumin ?) M: 1- 91 Peptone may be foinuMl l>y hydration. Clif/me : its oriulcj cliariU'tur. Antisrjitic projaTtic's of gastric juice. Ai'tificiiil digestion. I'rejiiiiiitioii of ]K'psiii extracts : () Extract M'itli dilnto liydro- cliloric acid (0. 2 p. c). (c) Glycerine extract, (d) Glycerine extract after delivdration l>v alcoliol. TIFK .VCT OF 8ECUETION AND TIIK MoVF.MKXTS OK THE STOMACH. During digesti(jn the mucous moml)rane is flushed with blood. Movements of the stomach cause currents in the food; their importance. Inasmuch as normal secretion is [> )ured out after division of all the nerves (vagus and splanclinic) the mechanism of secretion seems to bii local, tlKjugh it is pi'ol)alily under the control of the nervous system. As digestion is affected by emotions, etc., there must be a nervous mechanism by wiiich impulses are con- veyed to the stomach. The effects of section and stimulation of nerves. Circumstances affecting gastric digestion. The study of Alexis St. Martin (Beaumont). VomitiiKj : Pyrosis : simple character. Vomiting a rejlex act ; centre in the medulla. IMAGE EVALUATION TEST TARGET (MT-3) h. /4 ^ A / (A 1.0 I.I 1^12.8 |50 '*•■■ ^6 |3.2 ^ lis. 2.5 2.2 11-25 i 1.4 2.0 1.8 1.6 Photographic Sciences Corporation 23 WEST MAIN STREFT WEBSTER, NY. 14580 (716) 872-4503 a\ i\ -b \\ '^\V"Q ^t% ^ -A^^* %^ 92 Muscular mechanism by which the gastric contents are ejected. The relaxation of the sphincters. The part taken by the respiratory system. Vomiting owing to direct action of the centre as by il'ru))in or Hydro- [bilirubin, a "reduction "product. Cholesterin. Fatty acids. Insoluble soaps of Ca and Mg. LExcretin (C, H, 0, 8) crystalline. ABSORPTION. Chyle : comparison with lymph and blood. Fats : absorbed mostly through the villi and con- veyed by the lacteals into the venous blood. A small quantity by the portal circulation. Recent invedlgation on fat absorption (Schiifer). Protelds : mostly by tlie smaller blood vessels of the portal system. 99 In part by the villi (?) Sar/ar: chielly by the blood vessels of the portal system. ^ Absorption nccordinrj to the laws of diffunon coUoZT' ''"^^''"'''''' '"'^'-'^'osls ; crystalloids and Inferences from the action of purgatives like ma-- nosium sulphate. ° The marked loss of water in the large intestine ; equilibrium in the small gut. AOmrmal; Traun.itio fistuhe; alteration in the reaction of saliva in pregnancy (Beers), and certain diseased states ; dyspepsia ; its multitudinous iorms • constipatioi. diarrhctM, dysentery ; intestinal obstruction! BEMONSTKATIONS. Comparative : The stomach of a frocj, bird, rumin. ant, carnivore, etc. The action of saliva on starch, liapidity of the action. . I^estruction of digestive power by boilin*^. Extmcts of tlie mucous membrane of the pig's stomach. Artificial digestion with the same, of fibrin, etc. Influence of: reaction; temperature, etc. ' Character of the products formed. Pancreatic extracts : Artificial pancreatic digestion of proteids, starch fats. * 100 Influence oF vniyitig conditions. Tendency to putiof action. Comparison with artificial gastric digestion in tliis respect. ForniJition of leucin and tyroain. Bile : Reaction, color, absence of albumin, presence of mucus. Bile pigiiKi'its and cholesterin prepared from gall stones. The l)ile salts and bile acids. Test for bile pigments ((rmelin), Test for bile acids (Pettenkofer). Emulsifying power of bile. Precipitation of gastric digestive proteids by bile, (or •bile salts). Teristaltic movement of the intestines. -Naturally injected lacteals. X. Excretory Processes. No sharp liiiG of deinarcfitiun between secreiio7i and excretion. ^ Excretions are useless or Iiarmfiil ; secreti, ns serva, some further special use in the economy. Similar physical and chemical laws apply to both. 1"HY8I0L0GY OP THE SKIN AS A SKCRETING ORGAN. The skin is : 1. Protective. 2. Secretory. 3 A regulator of temperature, blood density, etc. 4. Seat of various sense organs. Histological and physiological : Epidermis (cuticle) ; dermis (cutis vera, corium) Transitional forms and suatification of ei)ithelial cells; pigmented layer, determining color of skin in races and individuals. Modifications of the epidermis : hair, nails, feathers scales, etc. * Muscular and elastic tissue of the corium; their lunctional importance. Blood supply of the skin. Glands: 1. Sudoriparous: simple tubular ; coiled at origm ; spiral near termination (adaptation to stretch- 2 Sehaceous: saccular; open into mouths of hair- lollicles ; oil glands of birds. Hairs: Papilla; hair follicle ; muscles 102 SWEAT AND ITS yCKETION. Sweating removes waste matters and lowers tem- perature. Amount of tlie perspiration determined by : moisture and tumpcruture of the air ; exorcise ; nature of food, etc. Method of determination of tliO (quantity of sweat for a given jieriod. Sensible and insensible perspiration. lleaction of sweat is acid usually (fatty acids) ; that of the pure secretion of tlie sweat glands, alkaline. Sweat contains about 2 per cent, of solids. Composition; water; sodium chloride ; several fatty acids ; neutral fats and cholestorin ; trace of urea. The smell of sweat due to volatile fatty acids. The secretion of the 'sebaceous glands ; function. Ilespiratory function of the skin. C 0„ : 4-10 "rams in 2-4 hours, linportance of this function in Amphibia. The varnished rabbit. Evaporation from the skin. Ahtioinnal: Excretion of drugs and poisons by the skin. Vicarious action of the skin. Skin diseases ; sebaceous cysts ; comedones. " Critical " sweatings. Recent Investigation .• Electric phenomena of secre- tion (Baylis and Bradford). 103 NERVOUS MECHANISM OF SWEAT SECUETI-^.V. Sweating may be and usually is accorunuuicHl by increased blood supply to the skin ; but such is not essential. Sweating from fear with i)allid .skin. Experimental: sweating in the soles of the feat of he cat on stimulation of tiie sciatic nerve, after ligature ot the blood vessels ; after amputation of the limb Sweating on stimulation of the central end of the 0;) , M. Source of phosphates : food ; metabolism. Carbonates exist iu but small quantity. 3. Jyitrogenous-crysfalline bodies: Derived from bodily metabolism. (a) Urea, uric acid. (b) I^ess oxidized forms of proteid metabolism: krea-. tmm, xanthin, hypoxanthin. (c) Hippuric acid, ammonium oxalate. 4. Non-nitrogenous : Organic acids : lactic, succinic, formic, oxalic, pheny- lie. e^vC. 5. Pigments: Special pigments : urobilin, purpurin, indican. Abnormal : Alkaline reaction of cystitis. Presence of blood, pus, epithelium, spermatozoa. Oxalic acid diathesis. Recent investigation: Experimental examination of the secretion of oxalic acid (dog) under a varying diet (Mills). Comparative: reaction of urine of carnivora is strongly acid ; of lierblvora, alkaline. Abundance of phosphates and sulpliates in the urine- of carnivora ; of carbonates .in that of herbivora. Abundance of uric acid in the urine of reptiles and birds. 106 Recent investigation. The urine of chelonians (Mills). Amounts of certain constituents of urine passed in 24 hours (I'arkes). Urea 33.180 grams. Uric acid 555 Phosphoric acid 3.164 Chlorine 7.000 Sodium 11.090 Total solids 72.000 Variations in the several constituents of urine ; on what they depend. Tl'T'ine becomes alkaline on star^dinsij in a warm •atmosphere. CO I ^ ^' + 2 H, = C O3 (N H.). Physical and chemical characters of urea and uric acid. THE SECRETORY PROCESS tN THE KIDNEY. iSTew methods of investiga<:ion : the oncometer, and oncograph. The kidney curve. Influence of blood pressure on the secretion of urine. The pressure in the glomeruli is the final determining factor. Variations of blood pressure effected experimentally and their influence on renal secretion. Complementary action of kidney and skin. 107 Effect ou the secretion of urine, of the application, of cold and heat to the skin. Eflect of injection of wacer into the blood. THE PA.KT TAKEX BY THE KENAL EPITHELIUM. The double renal blood supply in anipUihians. Experiments of Nussbauni (ligatures). Experiments of Heidenhain (injections). Albuminous urine after ligature of the vessels of the kidney. Recent investigations. Theories of urinary secretion (Bowman, Ludwig, Heidenhain, Nussbaum). We may conclude that the cells of the kidney possess, by virtue of their own peculiar constitution, the power to secrete all the constituents of urine. MICTURITION. Anatomical and pliysiolofjical. Structure of the bladder ; unstriated muscle cells ; their arrangement ; mucous membrane provided with mucou> glands. The sphincter of the bladder. The ureters : muscle cells ; mode of opening into the bladder. The urethra is a closed elastic tube. The secretion of urine in constant. Micturition may take place as an involuntary reflex act, but usually it is initiated by a volition. 1.08 The (letenuining cause of the reflex seems to be tlie quantity (and quality) of urine iu tlie bladder. The cantre has been experimentally demonstrated la the dog to be in the lumbar cord (Goltz). Tonic muscular contr.iction of the sphincter vcsicce- Ahnorrivd : Involuntary micturition in diseases of the spinal cord ; dribbling of urine ; nocturnal incontin- ence of urine ; action of the bladder under urethral obs- truction. DEMONSTRATIONS ; The properties of urine freshly voided. Urine of herbiv^ora and carnivora. Urine as modified by standing; sediments, etc. Quantitative estimation of sugar, urea, etc. Separation of uric acid and urea. Specimens of abnormal urine. XL Metabolism: Nutrition. The niiaiii of traiisforiuaticjus, taking place in the food between its entrance into the body and its leaving it as waste-products, is included under the term metabolism. Metabolism therefore deals with chemical changes and is governed by chemical laws. The energy latent in the food is set free by the meta- bolic changes of the body, and reappears as kin3tic en- ergy and heat. The series of changes between food and waste-products involves processes both analytical and synthetical. The total metabolism of an organ or of the body is but the sum of the metabolism of its component cells. The metabolism of ama'ba. GLYCOGEN. The liver is the largest gland of the body ; prepon- derance in foetal life ; abundant blood supply. Wide distribution of glycogen (animal starch) in the animal kingdom. Formation of glycogen as influenced by the kind of food. Fat cannot form glycogen. Disappearance during continued starvation. 110 Conversion into sugar after deatli. Theories of glycogen formation. Glycogen is probably a reserve of carbohydrates to be changed into sugar as required. Analogy with plants. DIABETES. Clinical and artiticial. How the latter is prodr.ced. The diabetic area of the Medulla is related to the vaso-motor centre. Vaso-motor changes in the liver after puncture of the diabetic area. Diabetes is due to changes in the glycogenic function of the liver originated by the nervous system; but the rnodus operandi is obscure. Clinical diabetes iiiHuenced by tlie nature of the food. FAT FORMATION. Adipose tissue : forming and formed ; its fluctuation* Pathologiciil fatty degeneration of various forms of protoplasm. The "ripening" of cheese. Fattening foods : carbohydrates, hydrocarbons. Fat formation from the fatty acids of the alimentary canal. Proteids as a source of fiit. Experiments of Lawes and Gilbert: For every 100 parts of fat of the food of a fattening pig, 472 parts fat laid up in the body of the animal. Ill Butter of the cow, wax of bees, etc. , out of proportion to the fiitty food taken. The fat of the auhnal does not correspond in composi- tion with the fat eaten. Theories of the formation of fat from proteids, carbo- hydrates, fatty acid, leucin, (amido-caproic acid) etc. THE METABOLISM OF THE M.VMMAKY (JLAND. Ilistolofflcdl : A compound racemose ghiud ; its cells i short columnar. Co'inposition of milk : Reaction alkaline : may be acid even in the gland. fl'roteiUs: j^'"^™'- „ . i Serum-albunnn. Solids:^ Carbohydrates: Milk sugar (lactose). I B^its. LSalts : phosphates of Ca, Mg, K ; K CI. The solids constitute about 10 per cent, of milk. Milk is an emulsion. The casein is " particulate" but may be fdtered out through porous earthenware. Cow's milk contains 3-5 per cent, of casein. Human milk about half that proportion. Colostrum is deficient in casein and rich in albumin. Colostrum corpuscles. The fatty globules of milk are surrounded by album- inous envelopes. 112 The naUuiil ounlliii^' of milk i.s owin^ to tlio coiivor- sioii of its milk smj^mi- into luitic ««'/r/, in tho prosenotJ of iiiicro-on^:Miisins. Comparison of milk und blood ooiiguliition. lUitter i.s ii niixtiim of niiuiy fats, but consists [»rin- cipally of palniitin, oloin, sU-arin. DEMUNSTUATlONa. Tho ]n'(^)Krties of milk. Till) [irotoids, fat and carboliydnitos of milk are all the outcomo of tlio protoplasmic activity of tho gland cells. Experimental feeding. lIistob\L,Moal invest igiitiou. Inlluence of tbe nervous system, drugs, etc. ^PLENIi: MKTAHOLISM. Anatomfical and i)hysiolopo9o fjolati.i.j capaMn of rapi.l decoiii- position into urea aiid n fatty portion. Water, when incroased, augments tho (|uantity of urea excreted. ^altt< are regulators of metal x.l ism. Practical Tlie regulation of diets so o,i to Qombino cheapness and physiological fitness. THE STUDY OF IJODILY ENEUGY. ^ " The animal body is a machine for converting poteiK tial into actual energy " (Fester). The energy available for the body depends on tlxo diitevencQ of chemical potential between the food and the waste-products. In estimating this the fiml result of chemical de- composition, not the intermediate stages, is considered. Instability of the molecule is associated with absorp- tion of energy and vice cersd. Heat and mechanical labor represent the totals of the processes by which energy is set free by metabolism. SOURCFS OF ENEUGY. The main source of all the energy of the body is from the oxidation of food. On the one hand we have proteids, fats, carbohy- drates; on the other their oxidation products as C O 118 U.n\ \\\o ])\)\o\\\'\;\\ oniMuy of ftwxl is iwltMilnltMl. How ovoilnMo ouovity is «»sn\,s \^1 JuihMion. l\oal, uml luovoinonl. 1 ,iohio"s ilivision ol foods \0Mi\ivivlot v or iion niiro- 1 It.' ^Miotis ; pinslio or ni(roji3;y Tho ^ntv.v^vM^o^if^ \y,\Y[ of ll\o \n<>l(MM)1o o^ nni'^olo i,q tlunvfoiv, prohi^bly, not (1^o<1 1\v nniMO»jlMr oxor- cis(^. Tlio muiMiiit of (" (>,, (n(M\M(Ml is in(M'o;\soil mmiy timos by iuus!Oul;\v l;^bov. T\\o o\|>orin\on(s of Kiok v'i- WislioiMwis on uuiMtMilnr onovgy. (\'>'nrlysi<)n : 'Vho onov^y o( ninsolo is nol diM'ivod from protoid u\«U,'U>olisiu «^\«^lusivoly. AMMA^. UK AT. Hoat is tlic outcomo of (ho oxidative prooossi^s of (bo l>(xiy. Those processes t.\ke place in the tissues. 1 1 '.I Ilf'iil iti II vrfiliwif iitiJtiHil iq llii> hmIi' icjin'mMitat iv« of 1 1ll' iliHi'H'iir(> III ('iii'i|jy ln'l wiM'ii rooij mimI wimln |iro(|iir,M. Till' iiiiiRcl(»Fi hikI ^liiiids (i3.sji«5oiully Iht- livoiy mo tlio rliipf flunrcMR III" Im'mI. Ilt'iii Ir IuhI cliii'dy I'V llii' mUii mihI Ihm^/^, I'liihiliilln'IMiiil ((',(l|lMt|iiO(|(>(| ;, iMtMldlMllMTfriMJ f WM,nri- liliiiiilt'il) iiiii| livl'i'ftuiliiii; iitiitiiMl^ cMmiifir"!! wm, \.h t(Mri- |M'ru.liiru. ViiiiiiliniH ill till' !i'iii|M>r(il.iir«' (»(' (lillnn'iit pJirtH of Him limly. 'I'|m» liver i'l llin vvnriiif'^f. t\v\rn,u. Tilt' lilniiil JH Mm j/hnit iiicdiiim of liniil, diMtrilMitiofi, Almormii.I : lower leiii|i(!nitiiri! of persorn vviMi j>nt'!iit- fovdinrn. oviilr. Mellioih of (lelenniriiiit/ llin liodily trinipMnitiirM, I )iH'i'rniU'.o« (or (ixilla. iiioiilJi, rnctiun, cU'.. ICxiiiiiples : (I'liijierfil lire oT Miiiii »'>7.00(!, Hwullovv 44.00. vvoir :;5.24. ViiriiiiioiH willi t\m\ Ke.x, iniiBC/iiJar ex(;rtion, ingo.s- (ioii ol looil. eir. Duily viiriiilioiiM : itri.i'iniii m from '> a.rn to pjn ; miniviHin IVom 1 1 \>.u\ to ',) a.jji. Diltbrotico about I". llKcnir-ATIoN OK TKMI'K' VVVWV.. 1 . \\y rarnUloriH in Iohh, owini/ to wannirif^ fifccn and iirino ; wariiiin;^' (!X|>ir(Ml air; evaporation of tin; water of iv,M]»initioii ; in radiation, conduction and ova['oration l)y the skin. 120 About three-quarters of the total loss takes place- through the skill. There is no pulmonary mechanism for heat production. Right ventricle is warmer than the left. The skin is the chief regulator of the loss of heat. Its sweat glands ; its vascular supply. Tolerance of very high temperatures. Increase of blood temperature with the application of cold externally. 2. By variation in heat production. Cold stimulates to increased oxidatic .n homoio- thermal animals and the reverse in poikilothermal. A curarized homoiothermal animal behaves like a poikilothermal one. Division of the spinal cord is followed by lowered temperature. Conclusions : 1. The production of heat is under the- control of the nervous system. 2. The mechanism is reflex. 3. There is a thermogenic centre (in the pons varolii ?) 4. The centre is probably double, i 6., a heat producing and a heat inhibitory division or centre. Patholofjlcal : Fever, in which there is increased meta- bolism. Heat of inflammation ; death from burns ; death from cold. 121 Influence of the nervous system ove,' nutritive pro^ cesses. Bearings on this subject of diabetes ; paralytic secre. tion of saliva. "Trophic" nerves. Pathological : acute bedsores ; degeneration of muscle m diseases of the spinal cord; inflammation of the eya after section of the 5th nerve ; pneumonia after section of the vagi. Demonstrations. The extraction of glycogen from the livin-? tissue of the liver and muscles. Conversion into suwar. XII. Thu Nervous Centres. The great nervous centres are the s[)inal cord and brain. THE SPINAL COKD. Anatomical and 2yhysiological : Coverings: Dara 77ia^e>' ; protective and supporting ; arachnoid non- vascular ; 2^^*^ mater vascular. Cauda equina ; fit um terminale (of gray matter). Fissures : Anterior median, posterior median. Cerebrospinal fluid. Central canal lined with ciliated columnar epithelium. Nerve-roots : Anterior and posterior. Line of entrance defines the lateral fissures. The grav matter of the cord forms a central crescent around which the white matter is placed. The cord histologically consists of nerve cells, neuro- glia, and nevve fibres. Two lateral halves of cord united by a gray (posterior) and a white (anterior) commisure. The gray matter : Anterior and posterior cornua. Histological : Nerve cells ; their interlacing process es ; .nerve fibres. 123 Special collections of cells : (a) Multipolar cells of -anterior cornu. (6) Clarke's column : large round cells at the base of posterior cornu in middle dorsal region, (c) Cells of lateral cornu {intermedio-lateral tract). The Course of the nerve roofs. Fibres of anterior roots pass : (a) Directly to nerve cells of anterior cornu. (b) To posterior cornu tlirougli gray matter. (c) To lateral white column of same side. id) To the antei'ior cornu of the opposite side through the isthmus. Fibres of the posterior roots pass : (a) Chiefly into posterior white columns, and after a •short course into the gray matter, some connecting with its cells, others passing to tlie opposite side of the cord. (6) Some to the posterior cornu directly and are likely connected with scattered cells of that region. Substantia gelatinosa of Eolando. Fibres of the white matter (fibre tracts) : These are medullated ; those of the gray matter non- medullated. Anterior ( ^^^^^ro-lateral column, column i ^"'6ct pyramidal tract or autero-median : (. column of Tiirck. r Crossed pyramidal tract. Lateral column, -j Direct cerebellar tract (cervical and ( dorsal regions) . 124 ■r, , • r Cuneato fasciculus (Burdach's columiO. , ■[ I'osterior medium column or tract of Goli^ \ distinct above middle of dorsal region. The size of the Jibrea and ita significance. Smallest in 'posterior columns (posterior median). Largest in crossed j)yramidal tract : the path of motor imjiulses. Large fibres of anterior column run in the direct pyramidal tract. Comparison of relative proportion of gray and white: matter in the different regions of the cord. Cervical and lumbar enlargements. REFLEX FUNCTIONS OF THE SPINAL CORD. A reflex action cannot be automatic, but depends essentially upon a stimulus reaching the centre from> without it. This stimulus usually acts upon end-organs. Latent period of action of the cells of reflex centre. " Summation " of impulses. Modification of impulses. Variations in the reflex according to: (a) The inten- sity of the stimulus, (6) Site of application of the stimulus, (c) Condition of cord (strychnia). Inhibition of reflexes by centres in the brain and the spinal cord. Excitation of reflexes through the organs of special sense. - _- - ' 125 Reflex time. Economy of cerebral energy owing to the increased facility of dincharge along certain lines in the spinal cord from repeated action (habits). The spinal cord is neither conscious nor intellirrent and th(High reflexes usually result for the benefit of the animal they may, in certain cases, lead to its des- truction. The co-ordination of a race and of an individual. THE COKD AS A COLLECTION OF CENTKES OF AUTOMATIC ACTION. are brought to a focus. 141 ACCOMMODATION. Accommodation is adaptation of the mechanism for €xact focussing of light, resulting in clear images on the retina. Dependence upon direction of rays (entering angle) and curvature of refractive surface. Diffusion circles. Schemer's experiment. The near point ; the far point. The emmetropic eye ; dioptric mechanism normal. The myopic eye : parallel rays focussed anterior to the retina. Long eye. The hypermetropic eye : parallel rays focussed pos- terior to the retina. Short eye. The presbyopic eye : there is defect of accomodation. Diagrams illustrating these conditions. HOW ACCOMMODATION IS ACCOMPLISHED. Tlie passive eye is accommodated for jiarallel rays (objects at an infinite distance). Accommodation for near objects results in : (a) Contraction of the sphincter of the iris leading to narrowing of the pupil. ° (6) Increase in the curvature of the anterior surface of the lens. The curvature of the cornea is not altered in accom- modation. 142 The lens is rondcred more convex anteriorly by the nction of the ciliary itixsclc in pullini,' forward the choroid, thus reliixing tlie suspensory lUjamott. ])iii,L(nini of the niechunisni. rurlvinje's iniiiges. VARIATIONS IN THE SIZE OF THE PUPIL. The pupil diJatcH with decrease of light; divergence- of the visual axes (distant vision) ; contracts witli in- crease of liglit and convergence of tho visual axes (near vision). The muscular mechanism of contraction. The condition of the eye in sleep. Nervous supply of tlie iris : 1. Short ciliary nerves from lenticular (ophthalmic, ciliary) ganglion, connected witli tldrd nerve. Long ciliary nerves from nasal branch of ophthalmic division ofjifth nerve. 2. The cervical sympathetic (through ciliary ganglia). 3. Nasal branch of the ophtlialniic division of the fifth nerve. Diagrams showing these relations. Experimental : 1. Division of cervical sympathetic followed by contraction of the pupil. 2. Stiniuhdion of the peripheral end of the same followed by dilation. .3. Division of the optic nerve is followed by dilation of the pupil. 143 4. Division of tkinl r.ervo with stimulation of the- optic nerve is not followed by contraction. 5. Stimulation of the peripheral end of the divided third nerve is followed by marked contraction. 0. Stimulation of the centra is followed by contrac- tion. The centre is situated in tha jhmt pavtof the floor of aqueduct of Sylvius. 7. The centre having been removed stimulation of the retina is not followed by contraction of the pupil. 8. Illumiuation of one eye is followed by contraction, of the ]»upil of the o])posite eye. ConcUmonn : 1. The contraction of the pupil is normally a reflex action. 2. The afferent nerve is the optic. Tlie ffferejit the third nerve. 3. The sympathetic is the efferent dilator nerve. Tonic action. 4. There kas^Hjciated action of the centre (or centres) for reflex action (see 8 above). A local mechanism. Exhaustion of the cerebral centre (alcohol, dying). Subordinate centre (centrum ciliospinale infer ius) in lower cervical rtkI upper dorsal cord. The accommodation centre is situated in the third ventricle ; connected with the most anterior bundles of the roots of the third nerve. 144 The nerves : ciliary, tliiouyli oplithalinic ganglion to third nerve. IMPEUFECTI0N8 OF THE OPTICAL APPARATUS. The fov&t centralis is the seat of the most perfect visual sensation. Spherical aberration of a lens owing to its form. How counteracted in the actual lens. Assistance from the iris. AdignuLtiHin : Owing to the refracting surfaces not 3ing perfect sections of a sphere. Diftorent foci. Generally traceable to the cornea. t In an eye astigmatic in the vertical meridian horiz- * ontal lines are focussed sooner than vertical ones and , vice versd. *i Hypermetropic and myopic astigmatism. Regular astigmatism ; irregular astigmatism. Chromatic aberration : Arises from the di tie rent refrangibility of the several rays of the spectrum ; rays of the violet end are focuss- I cd sooner than those of the red end. II Entoptic phenomena : MuscoB volitantes ; effect of tears on cornea ; the imperfection of the lens, margin of pupil, etc. The refracting surfaces are not truly centered on the optic axis. I m ;11 A5 VISUAL SENSATIONS. Sensory impulses originate in end-organ-ii. Sensation is the result of cerebral action on the im- pulses. The rods and cones are the anatomical elomeuts of the retina sensitive to light. The optic nerve is not sensitive to light. The blind spot. Purkinje's figures. Diagrams. Protoplasm is sensitive to light in lowly forms. Abundance of pigment in the retinal (or choroidal) epithelium. Retinal purple ; *' optograms." Visual purple is absent from the cones and fovea centralis ; wholly absent from the retinas of some animals. The yellow pigment of the macula lutea. The green lustre of the eyes of certain animals is due to a special choroidal layer (taiyetum, memhrana versi- color). It reflects light strongly and gives rise to interference colors. Electrical phenomena of the eye. Abnormal : Absence of pigment in eyes of albinos. THE STIMULUS AS RELATED TO THE SENSATION. The sensation outlasts the stimulus when the latter is of brief duration. K 146 Separate sensations are fused when the succession of the stimuli exceeds a definite rate. The stronger the light the higher must be the rate of succession. The duration of the " after image " is in proportion to the strength of the stimulus (light). " Positive " and " negative " ^.fter images. With gradual increase of the luminosity, the sensations increase ; but the increments of the sensations conse- quent on increments of luminosity gradually diminish. Lower limit of excitation (threshold) ; " maximum of excitation." " Range of sensibility " between these limits (Wundt). The smallest difference of light appreciable is about y^^ of the total luminosity. Weber'' s laiu : The increase of stimulus necessary to produce the smallest appreciable increase of sensation bears the same proportion to the whole stimulus. This law is of general application to the senses. Example : If 10 grams be placed in the hand it is found that 3.3 grams is the smallest appreciable incre- ment; likewise with 100 grams 33.3 is the smallest appreciable increment. DISTINCTION AND FU-SION OF SENSAMONS. When images reach a certain degree of retinal proxi- mity they are fused pyschologically (physiological fusion). Variations in discriminating power in the different parts of the retina. 147 The sensation areas of the brain are not sharply defined. ^ ^ Eetinal areas. COLOR SENSATIONS. Color is determined by the wave length of light. ^ Spectral colors : red, orange, yelloio, green, 'blue violet. Purple results from the blending of blue and red Natural hues may be imitated by the appropriate blendmg of certain primary color sensations with each other or with white or black. A color is more or less saturated according to the quantity of ivhite light mixed with it. '' Pale, rich, deep, bright, subdued, gla g," etc., as applied to color. Complementary colors are those which when fused (physiologically) produce white. The fusion of two spectral color sensations may give rise to a different spectral color (e.g. red and yellow producing orange). ' All the other spectral colors may, by duly varying the proportions, be derived from the three primary colors, (red, green, blue) with white. White may be produced by mixing the primary colors. The retina is most sensitive to blue, least to red. Theories of color sensations : . 1. Bering's chemical theory : 148 ■" Fu"ndam€ntal sensations ": white, black, red, yellow, green, blue. These are arranged in pairs so that the presence of one implies the absence of the other. This is owing to anabolic and metabolic processes ; or to constructive metabolism and destructive metabol- ism, which are always related. The substances are : Red-green, yellow-blue, black-white. Constructive metabolism or assimilation. Destructive metabolism or dissimilation. When dissimilation is in excess the lighter colors result (red, yellow) ; when balanced no color. 2. The Young-Helmholtz theory : All colors are the result of the appropriate mixture of certain primary sensations (red, green, blue or violet). Diagrammatic representation. Color blindness : Red blindness. Partial color blindness of the peripheral parts of the letina. Explanation by the above theories. After images : Positive and necjative. Colored after images. The " proper light " of the retina. Oscillations in color sensations. 149 VISUAL PERCEPTIONS. Perception is the final result of a chain of processes and IS psychical. ^ ^ocesses Field of vision. Localization of sensations. We cannot localize an object. Inversion of the image on the retina. Psychical effects from the use of colored glass. MODIFIED PERCEPTIOXS. W^^a^^or^: bright objects appear larger than dark ones of equal size. Contrast intensifies color sensations " Filling up " the blind spot. Visual perceptions independently of li^ht Phosphenes. ° Ocular spectra (phantoms). Appa7'ent size : ^J^he eye furnishes the mind with the size of an image Judgment of size is a complex process and success depends upon previous experience of a similar kind Various ways in which the judgment is affected. BINOCULAR VISION". " Corresponding " or " identical " points. Diagram showing them. Advantages of binocular vision. The effect of solidity in binocular visions is due to fusion of images which takes place in the cerebrum. 150 Stereoscopic fusion. Stereoscopic vision of different colors resulting in rhythmical oscillations of color. The psychical eflects produced by drawings and paintings. The muscular movements of the eyeballs, and possi- bly of accommodation, influence our judgments of size and distance. THE MOVEMENTS OF THE EYEBALLS. The muscles concerned. The co-ordinated action of these muscles in elevation, depression, adduction and abduction of the eyeball. The movements of the eyes in following an object result in keeping the image constantly on " correspond- ing" points of the retina. Double images in conseouence of departure from the above. The part of the brain concerned in such movements (see p. 133). Abnormal : Strabismus. THE HOROPTER. The horopter is such a line or surface in the field of vision that the images of the points in it fall on corres- ponding points of the retina. When standmg upright and gazing at the distant horison the horopter is a plane drawn through the ob- server's feet. . Diagram. 151 DEMONSTUATIONS. Inversion of the ima-e ou the retina of the excised eye of an albino rabbit. Changes in the size of the image according to size and distance of the ol)ject. Effects on the pupil of section of the cervical sym- pathetic ; of stimulation of the peripheral end. Scheiner's experiment. Movements of the pupil in the human subject Field of vision ; field of color vision. Blind spot. Purkinje's figures. Purkinje's images. Mixture of colors by rotation. Complementary colors. After images, Simultaneous contrast. Double images. Monocular and binocular vision. Stereoscopic effects. Irradiation. Angular rotation. Region of distinct vision. The yellow spot. The ophthalmoscope. Tests for color blindness. XIV. Hearing. Anatomical, Comparative : The ear in invertebrates is a sac pro- vided with modified (hair) cells, and enclosing otoliths and fluid ; in the highest mollusks (cephalopods) there is a membranous and cartilaginous labyrinth. Vertebrates : most fishes have a utricle communi- cating with the semicircular canals. Most amphibia have no membrana tympani. The frog has a membrana tympani which is connect- ed by three ossicles with the Fenestra ovalis. Reptiles have an appendix of the saccule correspond- ing to the cochlea ; a fenestra rotunda is present. In crocodiles and biixls the cochlea is divided into a. scala tympani and scala vestibuli. Snakes have no tympanum. In birds and reptiles the ossicles are represented by one bone, the columella. Highly movable external ear of mammals. The human ear : The external, middle and internal ear. Meatus : external and internal Ceruminous glands and hairs. Tympanum: an air chamber; contains vibrating mechanism : Membrana tympani and ossicles (malleus, incus, stapes). 153 Communication with pharynx by the Eustachian tube. Membrana tympani : shaped like a shallow funnel ;•. the uniho. Muscles : tensor tympani, laxator tympani, stapedius. Handle of malleus attached to membrana. Internal ear (Labyrinth). A bony labyrinth having 'perilymph around a membranous labyrinth enclosing endolymph. Bony labyrinth consists of: Vestibule, semicircular canals and cochlea. The fenestra rotunda is situated in the bony wall' between tympanum and scala tympani; ihQ fenestra- ovalis in the same, opening into the vestbule. The system of spaces filled by endolymph is the only- part containing auditory end-organs. These spaces all communicate with one another : the semicircular canals with the utricle directly ; the ductus cochlearis with the saccule through the canalis reuniens ; and the saccule and utricle by the saccus endolymphaticus. There are auditory hairs on the maculce of the ves- tibule^ and on the cristm of the ampullce of the semi- circular canals. Otoliths within the vestibule and ampulhe. The spiral cochlea ; divisions and connections. . .-^ ' Minute anatomy of the cochlea in special details 154 Physwlogical, The external car in man ; its importance in animals with large movable ears. Memhrana ty)npani. Has no fundamental note of its own. " Damping " effect of the ossicles. Auditory ossicles. Vibrations are conveyed by the ossicles to the endo- lymph of the labyrinth with, dlmlnhhed amiAitude but increased intensity. The ossicles vibrate en masse. Muscles : Tensor tymj)ani : by its contraction acts as a damper ; when quiescent prevents the membrane from being pushed out unduly. Laxator tympani : may act to draw the drum head outwards. Stapedius : prevents too violent shocks being com- municated to the endolymph through thp stapes. The action of these muscles is probably owing to nervous reflexes. Eustachian tube : Maintains equilibrium of pressure. Is open during swallowing. Abnormal : Rupture of membrane tympani ; thickened and in- drawn membrana ; catarrh and suppurative inflammation of the tympanum ; continuous closure of the eustachian tube. 155 Physical : Sound viewed physically and physiologi- cally. Sound is duo to vibrations of the air. When these are rhjfkmkal they produce a note. A note has (a) Loudness dependent on the ampl'i. tude of the vibration. (6) Pitchy determined by the rapidity of the vibrations, (c) Quality, decided by the over-tones accompanying the fundamental note. Harmony, discord, beats. Sympathetic vibrations. AUDITORY SENSATIONS. The terminations of the auditory nerve are connected with the nuicidce and crlstcu and with the basilar membrane. The end-organs are stimulated by the vibrations of the endolymph. While this mechanism is intact deafness cannot be uhsolute. Conduction of sound through the bones oi the skull. The organ of Corti may be concerned in the origina- tion of impulses which give rise to the perception of relative pitch; but this is not demonstrated, and there are serious objections to this view. The basilar membrane may, possibly, discharge this function. Complex auditory sensations arise, it is likely, from the mingling of primary sensations. 150 Inaudible tones : variations with groups of animals^ races of men, and individuals. Entotic phenomena. Aiulitonj judf/menta: " Projection " of sound into the external world. We judge of the source, distance and direction of sounds by their loudness, pitch, quality, etc., but very imperfectly. Sounds not previously hoard are misleading ; ventrilo- quism. Ahnot'iwd : Deafness from brain disease^ XV. The Sense of Smell. The essential olfac^.ory end-organs are situated in the mucous membrane of the nose ; the relative extent of the mucous membrane in different animals seems to bear some proportion to the acuteness of smell. In man the olfactory organs proper are limited to the upper and middle fossce of the nose. The nose is lined with ciliated epithelium. The olfactory cells. Odorous particles reach the olfactory region hv diffusion and by inhalation. Odorous particles in lirjuids (solutions) cannot be smelled when in direct contact with the n.ucous mem- brane of the nose. A certain period of stimulation precedes the develop- ment of the sensation, and the latter outlasts the stimulus. The localization of odorous bodies is very imperfect Fungent substances excite the fifth nerve, but do not •cause smell properly so-called. Subjective sensations. XVI. The Sense of Taste. Taste-hwls and other modifications of tlie epithelium. The lingual (gustatory) nerve is distributed to the' anterior part of the tongue, the glossopharyngeal to the posterior part and the pharynx. Substances must be dissolved in order to be tasted (chemical stimulation). Taste sensations may be generated by mechanical and electrical stimulation. Tastes : Sweet, sour, saline, bitter, etc. Some " tastes " are really smells. Subjective tastes. Abnormal: Deficiency of taste and smell often associated. XVII. General Sensibility and Tactile Sensations. Various forms of eiid-organs in the skin. General sensibility. Perfect localization of tactile sensations. A tactile sensation is replaced by that of pain when the epidermis is removed. The specialized sensations are those of touch tern pemture and of muscul:.r action. All these sensations merge into pain when sufficient- ly intense. PRESSURE SENSATIONS. Weber's law applied to pressure sensations. su.t"n f '"'" ''"^ '''' "^"'^"^' ^^"«i^^^« to pn.s- sure stimulation. ^ Variations of pressure more reaJily distinguished when successive tJian simultaneous. A cold body is pronouncea heavier than a warm one ' ot equal weight. Eifect of contrast. ir.o TACTIT.K SENSATIONS. " Kiolil of tiuu'li " ('om|)osiMl of taotilo mviis. liuprovonuMit in touch tmoouMo to nioro exact limi- ia\\on of {\u\ siMisation aivas in the Itrain. Krron(M>ns judiinnMUs : ((0 I'^roni irritation of tho norvi's of tho stuni]) of an anipnlatoil linil>. {!>) Aris- totle's I'xjH'rinu'nt. TllK TKMPKKATUIU': SKNSK. Tho t(MU]HM-aturo of bodios must ho (iiffcront from that of tho surfai'o o\' skin to which thi»y aro a])pHocl l^eforo tuoy can give riso to any sensation of tcm]HU'atur(>. The intensity of tho sonsatioi: is in in-oportiou to tho m]>idity of tlio change in tho tciupcraturo of tlu> skin aa well as the actual teni|-.eraturo of tho stimulating body. Tho range of most accurate sensation is between 27 and oo'-'' C, i.e., lear the normal temperature of the boily. Tho regions most s'nisitivo to temperature do not correspond with those most sensitive to pressure. There is probably a special nervous apparatus for each of the L^enses of pressure, touch and temperature. THE MUSCULAR SENSE. This sense is associated with muscles when in action, and to some extent when at rest. It is of peripheral origin ; but may be closely related to conscious volition. mi Mnurmd. loromolur ala^y: i„co.or,l(„ation r^latcl I" l".s,s „l l!„ ,„u,se„|„, „,,„„ „,„, ^,^^^j,^ ^^ _^^^^^.^^^ K.M«,„l mv,.,ti..al,i„n. „„ ll,. to„,i„„,.w „„,,,, ,o,m,.l,l- KXI'HrilMKNTH. I.I >;a,:rmi..Hli,„. „f tactile ln„U}z.,lion ca,,a,:ity with ^'"""' ''"' " '"■ >"'^ti'I «'mi,a.s.s..s (l.luntor criai,,,,,.,!, P""il, .li|.l".l „,t,. I,„t wat.r f7l."J to ll,„ .sa„.„ part., «, ■ 3. Mimcidai' feline. Ifei,//,./., («) l)(a„„„inati,„, or 11,0 H,„alle,t .lifl„,.„„ce in w.M..I,t a,,,.rocial,le wl,.„ tl„> wei.-ht i« ;,al,| i„ tl,. 1,,,,,] (/') Kcpct with the hand an.l arm ,,„p,,orto,i on a tiihlo (.soiiso ofii.-cssiire). 4 E«ti,natio„ .,{ the p,;,/„n-l!on„,to dllfcrmcc appr.. c.aW„. CO When the weights are li.-ht. «ay I Ts 4, ., «™n., , and (/,) when heavier, ,,ay, 10, sio.'sOo; I'm;, jou, etc., gram,*!. 5. l'l„n.,in,, the finger into nrercury and then gmdr,. ally withdrawing it. ^ 6. I'laeing two light weights, one cold and the other warm, on the tip of the finger, forehead, etc. 7. Seleetion of central spot in the palm of the hand ■"'d a,.t,hoatmn of a warm body and then of a light leatJier to thm. » ieatlier to this. L 162 8. Placing the elbow first in warm water and then in a freezing mixture. There will be a sensation of pain in the fingers and of cold in the elbow. 9. Aristotle's experiment (tactile delusions). Taste and smell. 1. Pinching the nose tightly, with the eyes shut, attempt to distinguish between pieces of apple, onion and potato. 2. Wipe the tongue entirely dry, and place on the tip a crystal of sugar and on the back part one of qui- nine, neither will be tasted until dissolved. 3. Apply non-polarizable electrodes to different parts of the tongue. The taste experienced is acid at the anode ; alkaline at the kathode. 4. Place two pieces of sugar of equal size one on the tip and the other on the back of the tongue. The sen- sation will be most acute at the tip. 5. Place a drop of solution of quinine on the tip of the tongue ; it will be but little tasted ; place another drop on the back of the tongue, it will be readily tasted. Sound and Hearing. Sound from vibration ; pitch ; loudness ; quality ; overtones ; resonance ; harmony ; discord, etc. Estimation of the direction and distance of sounds. Note. — Many of the above experiments are after Foster and Langley. XVIIL The Voice and Speech. Voice is produced by the vibration of the vocal bands •(cords). Anatomical and v^siological. The laryngeal mechanism consists of : A skeleton composed of cartilages, held together by ligaments, per. mittmg a certain degree of mobility of the cartilages on each other. * These movements are effected by muscles; and their purpose IS the regulation of the width oi the respiratory opemng ^glottis) and the degree of approximation and tension of the vocal bands. The cartilages: The arytenoid cartilages are of especial importance in voice proi^uction. The processus vocalis. The attachment of the vocal bands. The superior vocal bands (false cords). Ventricle and sacculus laryngis. The rima glottidis. The mucous membrane of the larynx. The muscles grouped in antagonistic pairs. Iheir attachments. The "sphincter " of the larynx includes the : J-f^yro-ary-e2ngloticus. 164 Thyro-arytenoideus externus. Thyro-arytenoideus internus. Arytenoideus posticus. Collectively and singly, except the last, they tend to- close the glottis, sphincter-like. Mechanism for widening the glottis; tighteninc/ the vocal bands ; slackening the vocal bands. Nerve supply of the vocal mechanism. The superior laryngeal supplies the mucous membrane and the crico-thyroid. All the other muscles are supplied by the recurrent (inferior) laryngeal. Effects of division of the laryngeal nerves. The utterance of a note involves complex co-ordina- tion. The requirements for the utterances of a note are : 1. A' certain degree of tension of the vocal bands. 2. Approximation of their edges, which must be free from irregularities. 3. An expiratory blast of air. Resonance chambers. The quality of the voice is dependent chiefly on the influence of parts above the vocal bands. Vibration of the vocal bands. The registers of the voice. The chest voice ; falsetto voice. In the chest voice the vocal bands vibrate throughout their whole breadth ; in the falsetto only in a portion of their breadth. 165 The range of human voices. Male voices classed as : bass, baritone, tenor. Female as : contralto and soprano. Recent investigation : The pitch of the voice • the registers ; the falsetto voice (Mills). SPEECH. Speech as distinct from voice. ^ The vowels : each has its own characteristic disposi- tion of the parts concerned in modifying the note pro- 'duced by the vocal bands. Illustrative examples. Classification of consonants. 1. According to the place at which the modification takes place as labials, dentals, gutturals. _ 2. According to the character of the movement giving rise to them as explosives, asperates, resonants or nasals. Whispering is speech without the use of the vocal bands. Abnormal : Tumours on the vocal bands ; paralysis of the muscles of the larynx. DEMONSTRATION. The laryngoscopic demonstration of the glottis. («> In respiration, (bj In phonation. XIX. Locomotor Mechanisms. The movements of the limbs are effected by the muscles acting on them according to the mechanical principles governing levers. Lever of first order p f W ; nodding the head. Lever of second order p w F ; raising body on toes by muscles of the calf. Lever of third order w P~ F ; raising forearm by biceps. Examples of the third kind are most common; of the first rare. Various kinds of joints. In the erect ijosture the line of gravity must fall within the area of the feet. The line of gravity of the head falls in front of the occipital articulation. The centre of gravity! for the combined head and trunk lies at about the level of the ensiform cartilage ; the line of gravity of the whole body passes in front of a line drawn between the ankle joints. The weight of the whole body is therefore sustained by the arch of the instep. The mechanics of walking ; standing on one foot ; Tunning; jumping. The locomotion of quadruped?. XX. Reproduction and Development. The hypotheses by which existing organisms are accounted for are : 1. Ahiogenesis (spontaneous generation) : livino- matter derivable from non-living matter. 2. Special creation of each principal form. 3. Evolution : " Evolution is a progress from an in- definite, incoherent homogeneity to a definite, coherent heterogeneity, accompanying an integration of matter and dissipation of motion " (Spencer). Organic evolution relates to the origin of organized bodies. The principles of organic evolution : (a) All forms of life have been derived from one or a few antecedent forms. (b) There is in organisms a tendency to vary in form. (c) There is in organisms a tendency to inheritance of ancestral forms ("Heredity"). (d) By the principle of " natural selection " (" survival of the fittest ") certain forms survive, others perish. Origin and extinction of species and varieties. The following grow out of the above : other (a) Excess of development of some parts relating to liers. 108 (1)) Complete or partial suppression of some parts. (c) Coalescence of parts originally distinct (after Huxley). Ilitftorical : The doctrine of organic evolution did not originate with Cliarles Darwin Ijut was previously independently worked out with greater or less fullness by different scientists. Charles Darwin was antedated sliglitly by Wallace in the promulgation of the most complete form of the doctrine of organic evolution. The part of the doctrine of organic evolution really oric/inated by Darwin was " natural selection " ; " des- cent with modification '' had been previously announced. ** Organic evolution" is regarded by the gi'eat majori- ty of scientific men as a probable ht/pothesis. Objections to the liypothesis by Darwin himself and others. REPRODUCTION IX THE LO\VEST ORGANISMS. 1. Fission in the protozoa, and many unicellular plants. 2. Gemmation (budding) ininfusorians,coelenterates, torula. 3. Asexual conjugation in iufusoriaus, fungi. 4. Metamorphosis in insects. 5. Alternation of generations : In toenia solium, toenia medio-canellata, cysticercus cellulosa3, toenia echinococcus. 1G9 -6. Parthenoijencf^is in insects, crustaceans. 7. Sexual reproduction (without intermediate stages) in most vertebrates. The fundamental hioloesicula3 seminales. Metanephros. Kidney. Ureter. (Stir>'ug after Quain.) 176 THK rilYSIOLOGY OF DEVELOPMENT. THE NUTKITION OF THE EMIUiYO. Inasmuch as the ova of many groups of animals pass through tht'ir entire develo]inient in water, they must contain witliin themselves the energy (latent) which becomes manifest in the processes of development. The yolk of tlie bird's egg furnishes the nutriment for the development of the embryo. Oxygen passes through the shell to the tissues either by the allantoic vessels or directly. pAar to the development of the placenta the mam- malian embryo is nourished by diffusion. The placenta has nutritive, respiratory and cxcretor]/ functions. The same laws as govern the tension of gases, etc., in the respiration of the adult apply in the case of the in- terchanges between the maternal and foetal blood. Foetal blood contains relatively less ha3moglobin. Tissues of the foetus composed at first of but little differentiated protoplasm ; later they abound in glyco- gen ; this probably serves as the crude material for the developmental metabolism. Digestion is in abeyance during fcctal life ; the liver is functionally active, probably also the skin and kidneys. Meconium of the alimentary canal. The amniotic and allantoic fluids may contain urea and allantoin respectively. 177 The changes taking place in the circulation after birth are owing to changes in hlood pvesmre induced by al- teration in the envii-onment of the animal The work of the right vetricle is greater than that of the left in the foetus. The first respirations of the infant are due to stimu- lation of the respiratory centre by blood deficient in ^J^y^^n together with the influence of afferent impulses from the skin. PARTURITION. Variations in the period of gestation of di»ent groups of animals. In woman it lasts about 280 days. Mechanism of parturition. Parturition is a reflex act ; the centre is in the lum- bar cord (Goltz). The expulsion of the placenta ; after-contraction of the uterus preventing haemorrhage ; gradual fatty de- generation and absorption (" involution ") of the super- fiuous uterine muscle cells. XSL The Phases of Life. ■% At birth the child is nearly J the maximum length and aV the maximum weight. Relative proportion of parts. Rapid increase in stature and weight in the earlier years. TJaj£ digestive system : Saliva, gastric juice, etc., active. T^Mcirciddtory and respiratory system : Heart re- ativeiy larger ; circulation and respiration more rapid, which points to rapidity of metabolism. The absorption of is more rapid than the produc- tion of C Og ; constructive metabolism. The temperature is slightly higher than that of the adult (0.3). More urine is passed relatively to body weight; the quantity of urea, etc., is greater; of phosphates less. Lymphatic system is prominent. Large thymus and thyroid glands. .-^' The brain is large and the nervous system is more irritable. Stimulation of the cortex is not followed (in newly born animals) by the usual localized movements. The senses in the infant. • The dentition of the voiina rlnU • T!!l teeth ; permanent teeth. ^ The changes in both sexes at puberty Woman and man compjired. -' * ^•The declining man; the old man: weakness and ~1 ng.dit, ; cah.reous and ..t, degenir .S The efeds of the seasons. Hibernation. S/eep : Sleep is accompanied by loss of consciousnes Jfnd , Iower,„g of the rate of activity „f all those pfesl which are ceaseless. P^uoesses Condition of the eyes. Death : The object of an individual animal's existence is the ' reproduction of itself in offspring . ture iTlr""^ 7"^ '"" ^"^^'"^^ ''^'^' -d fi"-l rup- ture a the weakest point ; or by violent disturbances of normal processes, as in disease. Death is by heart, lungs or brain (Bichat). " * " Somatic death and tissue death. Demonstratio7is. The human placenta and membranes. v The same parts of other animals. The fa^tus of different animals. Microscopic sections of the embryo chick, etc., etc. ' / v« 4' Aw.t PPENDIX. CLASS LABORATORY EXERCISES.* FOODSTUFFS, ARTIFECIAL OUJESTION, ANIMAL LIQUIDS. I. Starch, Dextrin, Dextrose, Fats. C. K) > ^- STARCH. Insoluble ill cold water; dissolves iujper- t'ectly^ ail ojiiilosceiit li(juid with beat. 2. ^e cold solution gives a blue color with solution of iodine. 3. Heat gently in a test tube till the color begins to dis- appear, then immerse the tube in cold water ; the color will return. 4. DEXTRIN. Soluble ill water; the solution gives a red brown color with solution of Ltdiiie. ' 5. Treat as starch (in 3) ; the color vanishes but does not reappear on cooling. 6. DEXTROSE. (Grape sugar) crystalline, readily solu- ^ It- ^ ble in water, less so than cane sugar ; reduces metallic oxides. 7. Tests, (a) Trommer's : To a couple of drops of solu- tion (10%) of Cu S O4 add K H (or Na H) till a clear blue solution results, then add to this a small quantity of the CuW. C)» * These exercises are based on those, contained in thePracticiil Phys- iology of Prof. Burdon Sanderson, which have been in use, under the author's direction, by students of McGill University during the past five years, and have proved eminently suitable. Directions for individual work and for experimental physi'^ogy will be otherwise provided. J!' 4 '•f^tiSk 181 solution of sugar and heat gradually to bolfflg. Boil for half a minute and let stand. Note the various changes. Reactions: (I) Cu S O, + 2 (K Ojl|k Cu O + H, (2) Cu O is reduced by the sugar to Cuj 0. The light yellow that first appears is the hydratod Cu, 0. 8. Moore*. test: Heat a solution of sugar with solution of K II, the color changes to a shade of brown, the depth •> depending on the strength of the saccharine solution. 9. Bismuth (Biittger's test) : Heat a solution of sugar with a pinch of bismuth subnitratc^^a brown color and darlt preci- pitation (on standing) results. ** /l«^.t^ r |*t, .; 10. Fermentation test: A solution of sugar with ^little 'i'X Y yeast added placed in a test tube and kept in a beaker of -jc^ .^ water at about 17'^ C gives off Og and forms alcohol. ^ Reactions : €„ H„ O^ = 2 (C, H,. H) + 2 C 0,. - 11. Conversion of starch into dextrose : C,^.* , Oy V ' > "S'^ ^.C^' , ' •- J, To a dilute solution of starch, add a few drops of dilute . » " ." ^, S O, and boil for 5-10 minutes. n' • j^ ^^^ V--^/*" ^'"*^"^ '^ ^J|B The starch solution becomes limpid. J^ ' '' A-t-sllL' , Test for sugar by Trommer's method. "# The liquid contains also dextrin and unaltered starch. 12. Fats. Insoluble in water; soluble in ether, hot alcohol, ■^"' ., chloroform, benzol, carbon bisulphide, turpentine, etc. 13. Boil a little butter in a solution of K O H in a beaker ^ or porcelain capsule, for souic time, a soap is formed ; test by shaking up with soft water. ~ To some of the potash soap add a little Ca Olg in solu- tion; a calcium soap (insoluble) is precipitated. Eepeatwith Mg S O4. 14. Add to the potash soap in a test tube a little strong 4^- ^ ej.'^n '' ^^^ 182 H, S O4 and boiipili standing a layer of fatty acid rises to the top ; it smells of butter. Tests: (a) Pont over paper a little ethereal solution of fat ; on tho cvaporalfen of the ether, a charaeteristic stain rtsuiains. ^ (b) Pour a little ether over the suspected licjuid («.(/. soap solution) ; rapidly filter into a elean dry watch gla.ss or teat tube ; evaporat*! ; if fat is present it will remain m thd glass. This test applies also to fatty acids. Reactions : m • } • Potassium Potassium />,, Tri-oleiu. tt 1 x ^ • 1 x (jrlycerine. Hydrate. tri-oleate. •' 3 (Cu H„ O,) + 3 K O H = 3 (C,i H3-3 0«) h C3 ^^(O H), o(3(ChH„0,)) Oleic acid. ■"X K3 } -I 3 II.,S O4 - G ((.\, H3, O,) + 3 K.,SO , Inference from the experiments of exercise I: Starch is insoluble in cold water ; imperfectly soluble in hot v> water; gives a blue color-reaction with iodine; may be eon. 7, verted into dextrose. Dextrin is soluble in water ; gives a red color-reaction with iodine Dex^/ose is .soluble in water ; reduces metallic oxides. ^ Fats are compounds of glycerine and a fatty acid ; may be decomposed by a strong mineral acid ; can form soaps ; are insoluble in water, etc. ^ *' -C 11. Foodstuffs. MILK, FLOUR, BREAD. These furnish speciiuens of all the classes of foods, organic And inorganic. y !• MILKt Reaction alkaline. Specific gravity 1025 to 1030. Skimmed milk has a "higher S. G. ^ (a) PBOTEIDS. Place about a wine-glassful of milk ^ in a flask, add a few drops of dilute acetic or sulphuric (25%) acid ; gently warm to a little above blood heat ; a granular precipitation of asein (with fat) will take place. Let stand. (b) Treat in a similar way with a few drops of extract of j^jgtoeTinet; a gelatinous firm clot forms. Let stand. '^m: (c) Filter and test the filtrate (whey) for milk sugar (Trommer's test). ;^ The salts cannot be conveniently tested for on account of the presence of proteid matter ^- (d) Test the coagulated casein remaining on the filter for entangled fat (butter) as in chapter I, 14. 2. FLOUR. Wash a dessert-spoonful of flour through a piece of fine muslin hold as a bag. Test for starch and sugar (little or none). The remnant of the washing is gluten. It is very tena- . I ^'^ cious. It gives proteid reactions (Millon's reagent). U.iAv^ ' J:i^ 3. BREAD. Digest in a capsule with warm water. (> ^ tA^'**^ Filter ♦^^^ rough paper. Tes filtrate for starch and sugar. m f 184 Test the resida9%r proteid and starch. ConcluHions : Milk contains all the essentials of a food stuff (lats, carbohydrates, proteids and salts) ; the " particulatt?" casein and jj;lobula!' fat may be precipitated by chciuical trji ment; the salts are in solution in the water of milk. Flour contains starch and proteid matter. Bread, owing to the lutat used in cooking, has had paii|^^ ^ its original starch converted into dextrose. ^ I # ''' ^% X III. Proteids : Albuminous Substances- I ; preparation of Albumin : Cut up white of cfjjij; with soisHorH; dihito H-10 times with water ; lilttir tiirough liuen and afterwards thr()ii-— 'e^J-^ cipitate falls. T. To another portion add a drop of solution of Ci^J^ O4 _^ / and a little of a solution of K O 11. A violet color appears. '^^♦^K l/i^^ 8. ACID-ALBUMIN. Add to a dessert-spoonful of the (ThJL, prepared solution of albumin a few drops of diluted acid (about J '^ (6%) ; gently warm for some minutes ; acid-albumin is formed ; ascertain that it does not coagulate on boiling by testing a separate portion j then divide into two parts. To one part ■»*■ ^ !x\ *^7^ -^-^o. IMAGE EVALUATION TEST TARGET (MT-3) 1.0 I.I 1^ 1^ M 2.2 IL25 M 1.4 1.8 1.6 Photographic Sciences Corporation 23 WEST MAIN STREET WEBSTER, N.Y. 14580 (716) 872-4503 iV iV 4^ ■^ <^ %^^^, ^.\ Wk\ i-'-- . 186 add solution of litmus and carefully neutralize with diluted alkali. When exactly neutral a precipitate will fall, soluble in excess of the reagent. Repeat with the other portion ; shake up and add to on ^ half dilute acid, and to the other half dilute alkali, till dw^^^' ^jl^il solved. IHM^ \\ ALKALI- ALBUMIN Add to a s.- 'ar portion of albumin a few drops of diluted alkali (K ji or Na H) and gently warm as before ; alkali-albumm is formed. Apply the boiling test. Neutralize with acid using the same precau" tions as for acid albun *^ Test the so^ubiUty of the neutrali- zation precipitate in alkalies and acids. COAGULATION POINT. Use three test-tubes with contents as follows : (a) solufion of albumin alone. (b) solution of albumin with a drop of .02% acid. (c) solution of albumin with a drop of .02% alkali. Heat gradually in a water bath (or on a sand bath), and note the coagulating point of each. '^^'^ " ' '^ ^ . >, Inferences : Coagulated albumin is insoluble in acids ; OAiid and alkali albumin are not coagulated by boiling ; are in- soluble in neutral liquids (water) but soluble in acids and alkalies. ^^ e aAUiL.*^^ J IV. Artificial Peptic Digestion. 1. The artificial peptic fluid may be made by extracting minced mucous mcmbrano „f the (pig's) stomacli with 0.2% H CI ; or by extracting tlio same with glycerine. 2. Test the former extract for Peptone (Biuret reaction). Peptone will be found owing to (self) digestion of the mucous membrane. 3. Use three test tubes with contents as follows : (a) A dessert-spoonful of 0.2% II CI and small pieces of washed fibrin. (bj A dessert-spoonful of 0.2% H CI and 10 drops gly- cerine extract of Pepsin, with fibrin. (c) A dessert-spoonful of water with glycerine extract of pepsin and fibrin. "^ 4. Place these thus labelled in a beaker containing water and keep for one hour at 85"— 38" C. At the end of this time test each for Peptone. At the end of 15 minutes test (6) for acid albumin. Digestion takes place only in tube b. The librin of tube (a) becomes clear and swollen. 5. Using extract of pig's gastric mucous membrane by dilute H CI, test the relative digestibility of (a) fibrin (b) cooked beef, (c) raw beef, (d) salt beef, (e) fish, (/) boiled white of egg, (g) milk. 6. Test the digestive power of the extract rendered alka- line. / / 188 7. Prepare a tube as before for digestion, then boil the contents ; cool and place under favorable conditions ; no digestion whatever takes place. Shake up fibrin with concentrated extract of pig's mucous membrane. Digestion will take place in the cold. ^ Tests for peptones : They do not coagulate on boiling. With caustic alkali and •\ trace of Cu S O4 they give a red color (Biuret reaction). CIJLUla.^^-^*-'^*^ ^^yth^^ fK^^'hjUyAJ) (XXXMA,AAA_-4r~>-il_ Ui A^^ W^ 6/C4>?^| L O^ ^(C ^y U' V. Salivary an^ Pancreatic Digestion. ^SALIVARY DIGESTION. , 1. Prepare some starch solution and let it cool (to 38°). 2. Test it for dextrose. If it contains none it is suitable. 3. Place a fceaspoonful of the starch solution in a test-tube and add a little saliva ; shake up, add a little of Trommer's sugar-test liquid and at once gradually heat up to boiling. The digestive action is often rapid enough to form sugar even under such circumstances. 4. Let another tube with starch and saliva stand in a water bath (beaker) for 5-10 minutes. Abundance of sugar will be found on testing. 5. Place some saliva in a test tube and boil ; after cooling, add starch and place in the water bath (beaker) at 35° to 38° C. After 10 minutes test for sugar. None will be found (if the boiling was thorou^rh). PANCREATIC DIGESTION. 1. Watery extract of minced (ox's) pancreas will suffice ; but glycerine extract is likely to contain no albumin, and the merest trace, if any, of peptone. The best menstruum is solution of Na, C O3 (1%). 2. Place in a water bath tubes with the following contents • ^ (a) Glycerine extract of pancrea:3, sodium carbonate solu- tion and a little teased up fibrin. 4 (h) Another tube with the same contents as (a) that have been boiled and allowed to cool. ■a' 190 J I (c) Ah (a) but with .2% H 01 instead of Na, C 0,. (d) As (a) but witli water instead of" Na._, C O.,. Digestion goes on best in f aj, feebly in (d), not at all in (h and c). Test each tube for peptone and (a) for alhdi albumin. 3. Test as in the case of saliva, the nmyhdytic action of glycta'ine extract of pancreas ; {ath to about one-third of its bulk, mix gradually, drop by drop, strong II N O3; crystals of urea nitrate ] C Ofiyr y\ , t H N 0;, [in characteristic glistening scales, form. jSlREATININ. Mix with some urine a few drops of a solution of Sodium Nitro-pntsside, then add caustic alkaU drop by drop ; a rod brown color results which d isapp(;;irs im standin g (Weyl's test). Horse's Urine. 1. Compare color, reaction (alkaline carbonates), smell, etc., cf horse's urine with that of man. 2. INDIGAN TEST. («) To about a tablespoonful of urine add an e(|ual volume of strong H CI, and cautiously, drop by drop, a saturated solution of chloride of lime (shaking well after each addition); a color some shade between green and blue will develop (Indigo). Sometimes the addition of H CI alone suffices, especially on standing, to develope indigo. The resolutions may be thus expressed : Indican. Indigo blue. 2 Cs H, N K S 0, + Os = 2 (C^ H^ NO) +.-2 K H S O^ Dog's urine also contains much indican. (6) Uepeat (a) using human urine. 1) /Ofl- O Y 2 . 5 ^ - 195 ABNORMAL ITIUNE. 1. Note change of snioll, color, reaction, specific gravity etc., in coiisoqucnce of the standing of frenh urine for some time in a room at the ordinary tcmperalure. SEDIMENTS. ('/) (Jarefnlly pour off from a ves- sel containing the urine, the greater part of the contiMits, tlien stir up the sedim«!nt. (6) Heat a little in a test tube; if the tiirhidity disap- , pears, it was owing Co ^f/vf^■.s rs(>liilf| |^ yi<.li l...:.f ^ jXS^>^^^ ^^) ^^ 't^i""«r*«liliilBr. HH.^lfit^« ^ ^ y^ It may be uric acid (unlikely). I^he latter is dissolved by a strong solution of caustic alkali. {d) Boil a specimen of urine without precipitate ; if a tur- bidity forms add 1-3 drops of strong II N (.,; if the turbidity does not disappear it is due to albumin. («) Oxalates arc soluble in Hydrochloric, but not in Acetic acid. C, O. Ca + 2 H CI = C, 0, H, + Ca CI,. 3. SUG-AR in urine can be detected by Trommer's tests and the others mentioned in Chapter I, and by Fehling', solution (Chapter VIII) . ^ . . ' ' l^ (i/^* ^i^-t^^^l^ XTA^^- ^^/^/J -^ ^^ \ ^. •7^ a- <^_-*> VIIL Urinary Quantitative Estimation. QUANTITATIVE DETKRMINATION OP 8UOAR. 1. Preparation of the Fehlinfi;'s solution : (d) Pure copper Hulphute, pulvorizeil, and dried by pressing between foldn of bibulous paper, .'14.(14 grams to be dissolved and diluted up to 500 c.c. (h) Pure Rochcllc salt (tartrate of sodium and potassium) in crystals, 173 grams to be dissolved in caustic soda (S. G. 1.34) 100 c.c. Dilute u[, to 500 c.c. As both these solutions ttind to change in composition they must be kept excluded from air (stoppered bottles). To make Fehling's solution add (a) to (h) gradually and shake well if necessary, to form a clear blue Holution. Keep excluded from the air. 10 C.C. of this solution reduce .05 grams of dextrose. Method of determination of sugar : (a) If the urine contains more than .5 to 1 per cent, of sugar it should be diluted. (6) The apparatus required : A Mohr's burette with stand ; a 10 c.c. pipette ; a 200 c.c. flask ; an iron tripod ; ii few very small flasks, funnels and filters. (c) Place in the 200 c.c, flask 10 c.c, of the Fehling's solu- tion and dilute with 40 c,c. of distilled wat«r. Fill the burette with the (diluted) saccharine urine. Heat the flask till the contents begin to boil. Then continuing 197 the heat let the urine flow from the burette cautiously. This i.s to be eontiiiued till tht blue color of tin <:oj)2>'r solution is whoUi/ rt^moved. To aKoertain this: when the j'obtr is seen to be nearly pone remove the flask t'roni the heat ami after it has stootl for a little hold it up before a vviiulow. If it b*; doubJful whether the fluid eontentH are colorlrss filter a few drops throuj;h one of the filtns into a small flask restinj; on white filter paper; if f jy eolor remains it can be discovered. If the filtrate is colored wash it back) into the large flask and proceed with the titration. Towards the end of the process the urine must be added a few drops at a time. Three estimations should be made to ensure a reliable result. ESTIMATION OF UREA BY THE HYPOBROMIDE METHOD. 1. Preparation of the liquid : Dissolve 100 grams caustic soda in 250 c.c. water and add 25 c.c. bromine. Preserve in a well-stoppered bottle. 2 Na H O + Br^ = Na Br + H., O 4^ Na Br 0. 2. Method of estimation with Dupr^'s apparatus : Introduce into the mixing vessel 15-20 c.c. of the hypo- bromide solution. Place in the receiver with a pipette 5 o.c. urine. The measuring tube is to be placed in a cylinder filled with water at the temperature of the room. Regulate the apparatus now so that there is no undue pres" sure uud see that the whole is air-tight. Tilt the vessels containing the urine and hypobromide solu- I 198 tion 80 that the fluids graduallij mix ; when the efFervescence has almost ceased, shake the containing vessel well and wait till all effervescence ends. The measuriusj; tube should be gradually raised as the liber ation of gas proceeds. When there is no more eff- /vescence sink the measuring tube into the water oT the cylinder. See that no leaking of gases takes place. Pluce the mixing vessel in water of the same temperature as that in the cylinder for 5-10 minutes. Read oflF the result after raising the measuring tube till the surfaces of the liquids inside and outside coincide. 37.3 c.c. of nitrogen at ordinary pressure and temperature correspond to 0.1 gram of urea. Reactions : COJ^g' + 3NaBiO + 2NaHO = 3NaBr + SH^O + Na2 C O3 + Nj. u / i J .M^ /> ^ , , . / v/^* » IX. Blood. 1. Test the reaction (with glazed litmus paper) of blood ; of serum. 2. Dissolve a small piece of blood clot in water. The solution is clear and the corpuscles have disappeared. 3. (a) Add a little dilute acid to blood in a test tube, A dirty coagulation results (owing to decomposition of the haemoglobin by which hcematin is set free, and to coagulation of proteids). (6) Heat a little blood in a test tube. A similar result follows. (c) Add to some dissolved dried blood clot a little hydro- chloric acid and then some potassium ferrocyanide, warm if necessary; a blue coloration (due to iron) will appear. SERUM. Proteids of serum (paraglobulin, serum-albumin). Heat some serum, diluted 5-10 times, in a test tube ; it coagulates. Eepeat with undiluted serum. Paraglohidin : (a) Dilute a little serum about 15 times with water ; carefully neutralize with very dilute acetic acid. The precipitate is soluble in excess. (6). Repeat without dilution ; negative result. Test the solubility of the precipitate of (a) with weak sa- line solution. 200 SPECTRA OP BLOOD. 1. 0-HiEMOGLOBIN. Dissolve a little blood ck water ; put from this, into a flat-sided bottle, three parts with water, enough blood to show (a) but one narrow baj (b) two bands ; (c) one broad band. 2. HiEMOGLOBIN. (Reduced haemoglobin), (a) Add to a preparation corresponding to 1. (h) abovf few drops of S (N H<)2, gently agitate. One broad band only will be seen. (h) Leave this exposed to the air for some time. It will again show the bands of 0-haemoglobin. 3. GO HiEMOGLOBIN. Allow C to pass into de| brinated blood (or solution of hsemoglobin) for 20 minutes. The blood becomes cherry red. Examine with the spectroscope : Two bands will be seen ij almost the same portion of the spectrum as those of O-haemo globin. Attempt reduction as in 2 (a). It is impossible. 4. ALKALINE HJEMATIN. Add to a solution of the biood clot, a drop of solution c caustic alkali. Note the change of color and the absorptio band to toe left of the D line. This solution can be reduced by S (N H^),. 5. A band is then to be seen to the right of D. and a s€ cond less distinct near E. • 1 H to WW I 11 I K III I'H lllll I «,J t ' in k1 H-t^