THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 LOS ANGELES 
 
 GIFT OF 
 
 Dr. Emil Bo gen
 
 A SHORT TREATISE 
 
 ON 
 
 ANTI-TYPHOID INOCULATION 
 
 CONTAINING 
 
 An Exposition of the Principles of the Method, 
 
 AND 
 
 A Summary of the Results achieved by its Application. 
 
 BY 
 
 A. E. WRIGHT, M.D. (Univ. of Dublin), 
 
 LATE PROFESSOR OF PATHOLOGY, ARMY MEDICAL SCHOOL, NETLEY ; 
 PATHOLOGIST TO ST. MARY'S HOSPITAL, PADDINGTON, W. 
 
 WESTMINSTER: 
 
 ARCHIBALD CONSTABLE & Co., LD. 
 1904.
 
 LONDON 
 
 PRINTED BY EYRE AND SPOTT1SWOODE, 
 
 HIS MAJESTY'S PRINTERS, 
 EAST HARDING STREET, B.C.
 
 Kiomedkal 
 
 nr 
 
 we 
 
 A SHORT TREATISE 
 
 ANTI-TYPHOID INOCULATION.
 
 PREFACE. 
 
 I AM by the courtesy of the proprietors of THE 
 PRACTITIONER permitted to republish in book form, 
 with amplifications, a series of three papers on Anti- 
 Typhoid Inoculation recently contributed to that 
 Journal. 
 
 I endeavour to give here a brief exposition of the 
 scientific principles involved in anti-typhoid inocula- 
 tion and a summary of the practical results already 
 achieved. 
 
 In Chapter I. I deal with the General Principles of 
 Immunisation; in Chapter II. with the Application of 
 these Principles to the particular Problem of producing 
 Immunity to Typhoid Fever; in Chapter III. with 
 the Technique and Clinical Effects of Anti-Typhoid 
 Inoculation ; in Chapter IV. with the Practical Results 
 achieved as disclosed in the Statistical Records. 
 
 In connection with these Records I have had to 
 consider the general questions which arise in connection 
 with the cogency of statistical evidence. 
 
 All these subject-matters not excepting that which 
 is concerned with the appraisement of the statistics 
 of anti-typhoid inoculation make, it is to be feared, 
 certain demands upon the reader in the form of 
 intellectual effort.
 
 VI 
 
 For the circumstance that intellectual effort is 
 called for in connection with the apprehension of a 
 difficult and intricate subject-matter I would fain not 
 be held responsible. 
 
 I may perhaps claim for the process of anti-typhoid 
 inoculation that- -first among the preventive inocula- 
 tions which have application to man it has been 
 followed up step by step by scientific research. 
 
 The curves of immunisation which I have plotted 
 out in the case of men inoculated with anti-typhoid 
 vaccine, and the similar curves I have recently plotted 
 out in connection with therapeutic inoculations of 
 staphylococcus vaccine and tubercle vaccine respec- 
 tively, are the outcome of a new system of technique 
 devised for the measurement of the content in pro- 
 tective elements of small samples of blood withdrawn 
 from the finger. 
 
 In conclusion, it may be well to make clear the 
 following points : 
 
 1. My work in connection with anti-typhoid inocu- 
 lation in the Army and it has included, in addition 
 to laborious experimentation, the inoculation of 4,000 
 British soldiers all over India, and the supply of some 
 400,000 doses of anti-typhoid vaccine during the South 
 African War has throughout been gratuitously given. 
 
 2. Anti-typhoid inoculation was suspended in the 
 Army 18 months ago at the instance of Mr. Brodrick's 
 newly-created Medical Advisory Board. 
 
 3. The Royal College of Physicians, to whose 
 arbitrament the question of the efficacy of the anti-
 
 Vll 
 
 typhoid inoculations was referred by the Secretary of 
 State for War, reported to him on July 27, 1903, in 
 the following terms : " After careful scrutiny of the 
 " statistics from both official and private sources 
 " which have been made available, we are of opinion 
 " that not only is a lessened susceptibility to the 
 " disease brought about as a result of the inoculations, 
 " but that the case mortality is largely reduced." 
 
 4. A committee has recently been formed and of 
 this committee I have the honour to be a Member 
 to take up again in connection with the Army the 
 consideration of anti-typhoid inoculation. 
 
 7, Lower Seymour Street, W.
 
 Vlll 
 
 TABLE OF CONTENTS. 
 
 PAGE 
 
 Preface - - v 
 
 CHAPTER I. ON THE PRINCIPLES OF PROTECTIVE INOCULATION AND 
 
 ON THE PHYSIOLOGY OF IMMUNISATION. 
 
 i. Machinery of Immunisation a definite Physiological Entity i 
 
 2 Machinery of Immunisation a Chemical Machinery 2 
 
 3. Chemical Relation between the Substances inoculated and the 
 
 Products of Immunity which are elaborated in the Organism in 
 response to the Inoculation - 2 
 
 4. Specificity of the Antitropic Elements which are produced in the 
 
 case of each particular Inoculation 4 
 
 5. Character of the Antitropic Elements obtained in the case where 
 
 the Vaccine which is employed contains in addition to substances 
 held in solution also formed Elements - 5 
 
 6. Disorganisation and Destruction of Red Blood Corpuscles by 
 
 Erythrocytotropic Substances and of Bacteria by Bacteriotropic 
 Substances ; and Selection of a Vaccine which will induce the 
 Elaboration of the Antitropic Substances required for the 
 Destruction of these formed Elements - 6 
 
 7. Physiology of the Reaction of Immunisation in relation to the 
 
 proper Adjustment and proper Interspacing of the Doses of 
 Vaccine - 8 
 
 8. Law of the Ebb, Flow, and Reflow, and subsequent maintained 
 
 High Tide of Immunity - . 8 
 
 9. Dependence of the Negative Phase upon the Dose of the Vaccine - 11 
 10. Cumulative Effects of two or more Inoculations - - 12 
 
 CHAPTER II. ON THE APPLICATION OF THE PRINCIPLES DEVELOPED 
 
 ABOVE TO THE PROBLEM OF THE PRODUCTION OF IMMUNITY 
 TO TYPHOID FEVER. 
 
 1. General Survey of the Problem 15 
 
 2. Nature of the Services which we desire the Typhoid Antitropins to 
 
 undertake in the Organism 16 
 
 3. Question as to what form of Culture, or what Bacterial Derivative, 
 
 will induce the Organism to furnish the Typhotropic Substances 
 which are required for the Prevention and Mitigation of Typhoid 
 Fever - - 17
 
 PAGE 
 
 4. Question as to whether the Inoculation of a Typhoid Culture which 
 
 has been sterilised by exposure to temperatures of 60 to 65 C. 
 is capable of inducing in the Organism the elaboration of the 
 Typhotropic Substances which are required 19 
 
 5. Observations which show that the Typhoid Culture preserves its 
 
 vaccinating Efficacy after Exposure to temperatures of 60 to 
 65 C. . 20 
 
 6. Observations which show that the Chemical Relations which 
 
 obtain between the Typhotropic Substances of the Blood and 
 Unheated Typhoid Cultures obtain also as between these 
 Substances and Typhoid Cultures which have been exposed to 
 temperatures of 60 to 65 C. 21 
 
 7. Conclusions which can be drawn from the evidence furnished under 
 
 the two preceding headings - - 21 
 
 8. Difficulties which stand in the way of the resolution of the question 
 
 as to what form of Anti-typhoid Vaccine is absolutely the best - 22 
 
 9. Brief account of the Method of making the required Mass Cultures 
 
 of the Bacillus Typhosus and Procedures (a) for Testing the 
 Purity of these Cultures, (b) for Sterilising, and (c) for Decanting 
 them without Risk of Contamination 23 
 
 10. Standardisation of the Vaccine - 23 
 
 n. Dosage of Anti-Typhoid Vaccine - 25 
 
 1 2. Question of the possibility of introducing the Vaccine in an effective 
 
 manner into the system by the Channel of the Alimentary Canal 27 
 
 13. Question of the possibility of achieving Protection apart from the 
 
 Preliminary Induction of a negative Phase 32' 
 
 CHAPTER III. ON THE TECHNIQUE OF ANTI-TYPHOID INOCULA- 
 TION AND ON THE CLINICAL SYMPTOMS WHICH SUPERVENE 
 UPON THE INJECTION OF THE VACCINE. 
 
 1. On the Technique of Anti -typhoid Inoculation 37 
 
 2. On the Clinical Symptoms which supervene upon the Injection of 
 
 the Vaccine - 38 
 
 CHAPTER IV. ON THE PROTECTIVE EFFECT OF ANTI-TYPHOID 
 
 INOCULATION AS EXHIBITED IN THE STATISTICAL RECORDS. 
 
 1. Fallacies and Errors which are incident to Statistical Records such 
 
 as those which come into consideration in connection with Anti- 
 typhoid Inoculation - 43 
 
 2. Question as to what Statistical Evidence may be accepted as 
 
 Coercive - - 47
 
 PAGE 
 
 3. Synoptical Table of all the Statistical Records relating to Anti- 
 
 typhoid Inoculation - 52 
 
 4. Critical Commentary on the Statistical Records set forth in the 
 
 Synoptical Table above - - 56 
 
 5. General Conclusions which emerge from the Sum Total of the 
 
 Statistical Records - 62 
 
 APPENDIX I. DETAILED DESCRIPTION OF THE PROCEDURE 
 WHICH HAS BEEN EMPLOYED IN CONNECTION WITH THE PRE- 
 PARATION OF ANTI-TYPHOID VACCINE en masse FOR THE USE OF ' 
 THE ARMY - 65 
 
 APPENDIX II. LIST OF AUTHOR'S PAPERS DEALING WITH 
 
 IMMUNISATION AGAINST BACTERIAL DISEASES, ANTI-TYPHOID INOCU- 
 LATION, THE MEASUREMENT OF THE CONTENT OF THE BLOOD IN 
 PROTECTIVE SUBSTANCES, AND KINDRED SUBJECTS - - - 74
 
 ANTI-TYPHOID INOCULATION. 
 
 CHAPTER I. 
 
 ON THE PRINCIPLES OF PROTECTIVE INOCULATION AND ON 
 THE PHYSIOLOGY OF IMMUNISATION. 
 
 THE problem of conferring protection against typhoid fever by 
 preventive inoculation is in reality a physiological problem. It 
 is the problem as to how to call into action, and how to direct 
 towards the end that we have in view, the physiological 
 machinery which is concerned with immunisation. 
 
 To do this we must learn all that we can with regard to the 
 nature and range of operation of the physiological machinery in 
 question, and all that we can with regard to the laws which 
 govern its functioning. 
 
 Inasmuch as the existence of the faculty of immunisation 
 is as yet altogether unrecognised by the physiologist, it may 
 at the commencement be well to set before ourselves the 
 evidence which establishes the existence of such a faculty as a 
 physiological entity. 
 
 That evidence is furnished on the one hand by clinical 
 observation, and on the other hand by immunisation experiments 
 undertaken in the laboratory. 
 
 The former, testifying as it does, on the one hand, to a 
 spontaneous recovery from bacterial infections, and, on the 
 other hand, to the acquirement by the convalescent of in- 
 susceptibility to further infection, furnishes, even taken by 
 itself, adequate evidence of the organism is furnished with a 
 machinery for immunisation.- 
 
 The efficiency of the machinery is attested 
 
 1. By the fact that it is now even-where felt that our 
 proper course in the presence of specific fevers of unknown 
 causation is to stand aside and allow the organism to develop 
 its own defences. 
 
 2. By the fact that the methods of treating tubercular 
 disease by the internal administration of antiseptics have been 
 practically everywhere laid aside in favour of methods which are, 
 at least in intention, methods for building up the constitution, 
 and for the increase of its defensive powers. 
 
 A
 
 2 ANTI-TYPHOID INOCULATION. 
 
 3. By the fact that it is now recognised that where 
 protective substances obtained from animals vicariously 
 inoculated are available, these supply the most effective 
 agency for combating bacterial infections. 
 
 MACHINERY OF IMMUNISATION A CHEMICAL MACHINERY. 
 
 In embarking upon the consideration of the physiology of 
 immunisation, we may take our departure from the general 
 proposition that the process of immunisation is in every case 
 associated with an elaboration of chemical products on the 
 part of the inoculated organism. Even where, as in the case 
 of anti-staphylococcic inoculations, the condition of immunity 
 which is achieved appears at first sight to depend upon an 
 exaltation of the power of the phagocytes, it is, as I have 
 shown l in conjunction with Captain Stewart Douglas, I.M.S., 
 in reality referable to the appearance in the serum of a special 
 class of protective substances opsonins. 
 
 The machinery of immunisation must, in conformity with 
 the above generalisation, be conceived of as a purely chemical 
 machinery. It is a machinery which elaborates, in response 
 to the appropriate chemical stimulus, the particular internal 
 secretion which is demanded for the purposes of immunisation. 
 
 I cannot, without losing touch with the practical end which 
 I have here in view, pause to consider the speculations of 
 Ehrlich with regard to the pattern and design of this chemical 
 mechanism. Valuable, and indeed priceless to the intellect as' 
 the conceptions in question are, we shall do well here to turn 
 aside from them to consider the practical question of the relation 
 which obtains between the chemical element which sets in 
 motion the machinery of immunisation, and the product which is 
 elaborated by that machinery. 
 
 CHEMICAL RELATION BETWEEN THE SUBSTANCE INOCU- 
 LATED AND THE PRODUCT WHICH IS ELABORATED IN 
 THE ORGANISM IN RESPONSE TO THAT INOCULATION. 
 
 The relation between the foreign element which is inocu- 
 lated we may convenientl}" speak of this, irrespectively of its 
 derivation, as the vaccine and the chemical product which 
 
 1 Prcc. Royal Society, October. 1003, and February, 1904.
 
 ANTI-TYPHOID INOCULATION. 3 
 
 makes its appearance in the blood of the inoculated animal 
 was first clearly discerned by Ehrlich. The correctness of 
 the conception which he formed of this relation was first 
 demonstrated by him in connection with his experiments 
 on ricin. 
 
 The chemical properties of the vaccine inoculated and the 
 product of immunity obtained were in these experiments as 
 follows : The substance inoculated was, as has already been 
 indicated, ricin, a chemical principle derived from .castor-oil 
 seeds. Ricin added to blood, whether in vivo or in vitro, exerts 
 an agglutinating and finally a disintegrating effect upon the red 
 blood-corpuscles. The vaccine employed was thus, in the con- 
 venient technical language of Ehrlich, a " haemotropic " poison 
 a poison which enters into chemical combination with the 
 blood. Experiments with the blood of animals immunised by 
 the inoculation of progressive doses of the poison showed 
 (a) that the red blood-corpuscles of such blood were quite 
 unaffected by an addition of ricin ; () that the red blood- 
 corpuscles of normal blood were unaffected when mixed with a 
 sufficiency of the serum of the immunised animal, and (c] that 
 . ricin was deprived of all its poisonous properties by digestion 
 with the serum of an immunised animal. 
 
 It was thus made manifest that the serum of an animal 
 which has been immunised by progressive doses of ricin must 
 contain an element which combines with the ricin, intruding 
 itself between the poison and the constituent of the blood, 
 upon which it is accustomed to fasten. We may speak of this 
 product of immunity, which has appeared in the blood, as a 
 ' ricinotropic element." 
 
 The data obtained by Ehrlich in this investigation were soon 
 supplemented by further data. In particular it was established 
 by the work of C. J. Martin ' that the chemical element which 
 is obtained in response to the inoculation of snake-venom is 
 an element which combines with that venom a " venenotropic 
 element ; " and further, that the chemical element obtained in 
 response to the inoculation of diphtheria-toxin is an element 
 which combines with that poison a " toxitropic element." 
 
 It was soon afterwards discovered that the subcutaneous or 
 intravascular inoculation of blood from an animal of different 
 
 1 Proc. Royal Society, Vol. 63. 
 
 A2
 
 4 ANTI-TYPHOID INOCULATION. 
 
 species is responded to on the part of the inoculated animal 
 by the elaboration of haemotropic elements in particular, of 
 haemolysins. It was then discovered that the subcutaneous 
 inoculation of milk is responded to by the elaboration of a 
 galactotropic element in particular, of an element which 
 confers upon the blood a power of coagulating milk. Later 
 again, it was ascertained that the inoculation of testicular 
 extracts and ciliated epithelium is responded to by the formation 
 of spermatotropic and epitheliotropic substances which possess 
 the power of arresting the movements of spermatozoa and 
 epithelial cilia respectively. 
 
 It had already been ascertained and it concerns us to bring 
 this into relation with the above facts that the inoculation 
 of bacterial elements is responded to by an elaboration of 
 bacteriotropic elements. Under this name we may group 
 together the various substances which produce, as the case 
 may be, agglutinating, bactericidal, bacteriolytic, or, as already 
 indicated, opsonic effects. 
 
 We are manifestly led up by all these facts to the generali- 
 sation that in every case the inoculation of a vaccine is 
 responded to by the elaboration of a vaccinotropic element. 
 It will be convenient though this will involve a certain 
 departure from Ehrlich's system of nomenclature to speak 
 of the products of immunity generally as antitropic elements, 
 or more briefly, antitropins. 
 
 SPECIFICITY OF THE ANTITROPIC ELEMENTS WHICH 
 ARE PRODUCED IN THE CASE OF EACH PARTICULAR 
 INOCULATION. 
 
 The next point to be insisted on is the specificity of the 
 antitropic elements which are produced in response to different 
 vaccines. The haemotropic, bacteriotropic, and other anti- 
 tropic substances spoken of above, exert in each case a specific 
 action upon the chemical substances which have been employed 
 as vaccines. A haemotropic element obtained by the inoculation 
 of a particular variety of blood is restricted in its action to 
 the blood of the animal which has furnished the vaccine, or 
 to the blood of an animal closely related to the same. In 
 a similar manner, a bacteriotropic substance obtained by the 
 inoculation of a particular micro-organism is operative only
 
 ANTI-TYPHOID INOCULATION. 5 
 
 upon the particular species of micro-organism in question. A 
 tubercle-vaccine, for instance, is responded to, so far as it is 
 known, only by an elaboration of tuberculo-tropic elements ; a 
 typhoid vaccine only by elaboration of typhotropic elements ; 
 a staphylococcic vaccine only by elaboration of staphylotropic 
 elements. 
 
 CHARACTER OF THE ANTITROPIC ELEMENTS OBTAINED IN 
 THE CASE WHERE THE VACCINE WHICH IS EMPLOYED 
 CONTAINS IN ADDITION TO SUBSTANCES HELD IN 
 SOLUTION ALSO FORMED ELEMENTS. 
 
 In the case of inoculations undertaken upon an animal 
 with the blood of another animal, we are dealing with a vaccine 
 such as is here contemplated. We are in such a case inoculating 
 red and white blood-corpuscles suspended in a plasma or serum 
 which contains a variety of albuminous substances. In the 
 case where a bacterial culture is inoculated, we are similarly 
 dealing with formed elements suspended in a solution which 
 may contain a variety of other bacterial products. It will 
 be instructive to consider w r hat will happen in these cases. 
 When \ve inoculate blood, we obtain as our harvest a 
 complicated mixture of haemotropic elements, in particular 
 erythrocytotropic elements, leucocytotropic elements, and 
 elements which we may group together as serotropic elements. 
 The first two of these disintegrate, respectively, the red or the 
 white corpuscles, the last-mentioned (or some of them) produce 
 a precipitation in the serum. Something exactly similar occurs 
 where an ordinary bacterial culture is inoculated. We obtain 
 here in response to the inoculation of the bacteria, a develop- 
 ment of bacteriotropic elements. These may, as we have 
 seen, agglutinate, kill, dissolve, or otherwise disintegrate the 
 bacteria. Further, in the case \vhere the liquid medium in which 
 the bacteria are suspended contains certain specific varieties of 
 toxins, we may obtain, as in the case \vhere diphtheria-toxin 
 or tetanus-toxin is inoculated, toxitropic elements in the form 
 of antitoxins which combine with and neutralise the poisonous 
 properties of the toxins. 
 
 Inasmuch as, in the case of preventive inoculation against 
 typhoid, we are concerned in particular to achieve the 
 destruction of such typhoid bacilli as may effect an entrance
 
 6 ANTI-TYPHOID INOCULATION. 
 
 into the organism we shall do well here to consider certain, 
 questions which have relation generally to the disintegration 
 and destruction of formed elements by antitropic substances, 
 and in particular of bacteria by bacteriotropic elements, 
 developed in the course of immunisation. 
 
 DISORGANISATION AND DESTRUCTION OF RED BLOOD- 
 CORPUSCLES BY ERYTHROCYTOTROPIC SUBSTANCES AND 
 OF BACTERIA BY BACTERIOTROPIC SUBSTANCES, AND 
 SELECTION OF A VACCINE WHICH WILL INDUCE THE 
 ELABORATION OF THE ANTITROPIC SUBSTANCES RE- 
 QUIRED FOR THE DESTRUCTION OF THESE FORMED 
 ELEMENTS. 
 
 It is impossible to conceive of formed elements furnishing, 
 while they remain intact, a chemical stimulus, such as would 
 induce an elaboration of antitropins complementary to the 
 chemical constituents of those formed elements. The appro- 
 priate chemical stimulus will be furnished only when solution 
 has taken place. 
 
 In point of fact it can be shown that, where foreign blood 
 is introduced into the animal organism, the formed elements 
 in particular the red blood-corpuscles are dissolved. Similarly 
 it can be shown that, where typhoid bacilli are introduced into 
 the blood or lymph, these also are dissolved. 
 
 The question of solution of the formed elements having in 
 these particular instances been set at rest, we are immediately 
 confronted with the question as to whether it is indispensable 
 for the achievement of the destructive antitropic substances 
 which we require, that the complex molecule which constitutes 
 the chemical basis of the formed element should be introduced 
 into the organism in an absolutely unaltered condition. It will 
 be recognised that upon the answer which this question 
 receives will depend the scientific justification for the em- 
 ployment as vaccines of bacterial cultures which have been 
 chemically altered by heating, or by other agency. 
 
 It will be convenient to commence by ascertaining what 
 modifications of the vaccine are permissible in the case of 
 inoculation undertaken with the design of conferring upon 
 an animal a power of haemolysing a foreign blood.
 
 ANTI-TYPHOID INOCULATION. 7 
 
 We may, as Dr. Bulloch has recently shown, substitute 
 for the intact or dissolved red corpuscles, which furnish the 
 vaccine ordinarily employed, the stromata of the red corpuscles. 
 We may go further still and may employ for our vaccine, in 
 lieu of the fresh stromata, stromata which have been desiccated 
 in an exsiccator. 
 
 These substitutions may, it appears, be made without any 
 sacrifice of efficacy. In point of fact, it is not certain that the 
 blood of an animal inoculated with a vaccine made from the 
 desiccated stromata does not hsemolyse more effectively than 
 the blood of an animal inoculated with intact red corpuscles 
 or with the simple watery solution of blood. 
 
 Dr. Bulloch experimented further (a) with stromata which 
 had been extracted with ether ; () with the ether-extractive ; 
 and lastly (c] with the haemoglobin apart from the stromata. 
 The animals subjected to these inoculations did not in any case 
 develop any haemolytic power. 
 
 These experiments afford very interesting extension of data 
 previously obtained in connection with bacterial vaccines. 
 
 The bactericidal, bacteriolytic and agglutinating powers 
 which may be developed in animals by the inoculation of living 
 typhoid cultures, and in man by the invasion of his organism 
 by the typhoid bacillus, are obtained with equal facility by 
 the inoculation of typhoid cultures which have been sterilised 
 by heating. 
 
 Exactly the same thing applies in connection with the 
 vibrio of cholera. 
 
 Mutatis mutandis, the same thing applies in case of the 
 staphylococcus. The increased phagocytosis and the very 
 favourable clinical results which I have obtained in acne, 
 furunculosis, and sycosis by the inoculation of heated staphylo- 
 coccus-cultures are evidence that a power of destroying the 
 staphylococcus can be developed by the inoculation of heated 
 cultures. 
 
 It is to be noted that, while it has been thus established 
 that the power of disorganising bacteria can be quite well 
 obtained by the inoculation of cultures which have been 
 chemically altered by heating, it is manifest that a departure 
 from the chemical constitution of the original culture is admis- 
 sible only so far as it proves itself to be a modification which
 
 8 ANTI-TYPHOID INOCULATION. 
 
 leaves unaffected that chemical element in the vaccine which 
 evokes the elaboration of destructive antitropic substances. It 
 is of interest in this connection to note that the German Plague 
 Commission l satisfied itself that the vaccinating power of a 
 plague-culture is impaired or abolished when the customary 
 addition of antiseptics is made to the unheated culture, instead 
 of (as is ordinarily done) to the culture after it has been heated. 
 
 PHYSIOLOGY OF THE REACTION OF IMMUNISATION IN 
 RELATION TO THE PROPER ADJUSTMENT AND PROPER 
 INTERSPACING OF THE DOSES OF VACCINE. 
 
 The success of an inoculation-process does not in any case 
 depend only upon the selection of the appropriate vaccine, 
 upon the aseptic preparation of the vaccine, and upon the 
 carrying-out of the inoculation in an aseptic manner. There 
 is required further, upon the part of the operator, a certain 
 comprehension of the physiology of immunisation, and, in 
 particular, an apprehension of the general features of the 
 reaction of immunisation. 
 
 LAW OF THE EBB, FLOW AND REFLOW, AND SUBSEQUENT 
 MAINTAINED HIGH TIDE OF IMMUNITY. 
 
 There succeeds in every case upon the inoculation of a 
 vaccine a negative phase, characterised by an impoverishment of 
 the blood in antitropic substances. With this ebb, or negative 
 phase, is associated a phase of increased susceptibility to bacterial 
 infection, or, as the case may be, of increased sensibility to 
 the toxic effect of the particular vaccine. This negative phase 
 generally coincides with a period of greater or less constitutional 
 distress. 
 
 The negative phase is succeeded by a positive phase, 
 characterised by the flooding of the circulating blood with 
 newly-formed antitropic substances. It may be presumed 
 that this phase is associated with a maximum resistance to a 
 bacterial invasion and a minimum sensibility to the poisonous 
 action of the particular vaccine. 
 
 There supervenes upon the positive phase a reflow, or sinking 
 away of the inflowing wave, leaving behind it a permanent, 
 or relatively speaking permanent, high tide of immunity. 
 
 1 Report, German Plague Commission, pp. 310-312.
 
 ANTI-TYPHOID INOCULATION. g 
 
 / 
 
 During this period the blood shows, as compared with the 
 period antecedent to inoculation, an increased content in 
 antitropic elements. Moreover, the organism seems to possess 
 during this period and it would seem even afterwards 
 a greater power of response to a renewal of the vaccinating 
 stimulus. 
 
 Basis of Experimental' Fact upon which the Law of the 
 Negative and Positive Phase rests. Inasmuch as the law which 
 has just been enunciated is a law of absolutely fundamental 
 importance in connection with the physiology of immunisation 
 it w r ill be well to set out clearly the basis of experimental fact 
 upon which it rests. 
 
 The law emerges for the first time in a paper of Ehrlich 
 and Brieger, 1 in which there was set forth a curve of the 
 reaction of immunisation. This curve, which is reproduced 
 below, sets forth the variation in the amount of antitropic 
 substances excreted in the milk from day to day during the 
 course of immunisation. The particular experiment which 
 furnished this tracing was an experiment in which tetanus- 
 toxin was inoculated into a goat which had already by 
 previous inoculations been rendered to some degree resistant 
 to the effect of this poison. 
 
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 Curve obtained by Ehrlich and Brieger, showing the content of 
 
 the milk in tetanus-antitoxin from day to day during the course 
 
 of immunisation. 
 
 The same succession of negative and positive phase is 
 disclosed in a curve of the reaction of immunisation, which 
 is furnished by Salomonsen and Madsen. 2 In this particular 
 
 1 Ztschfts.f. Hygiene, 1893. 
 
 2 Annales de I'Institut. Pasteur, 1897.
 
 IO 
 
 ANTI-TYPHOID INOCULATION. 
 
 case the curve sets forth the variation in the amount of 
 diphtheria-antitoxin in the blood and milk of a mare during 
 the course of immunisation. 
 
 t* 
 
 Curve obtained by Salomonsen and Madsen, showing the 
 
 content of the milk and blood in diphtherial antitoxin from 
 
 day to day during the course of immunisation. 
 
 As yet the law had disclosed itself only as the law which 
 governed the output of antitoxin from the antitoxin-forming 
 centres. 
 
 I may perhaps claim to have been the first to bring out by 
 my measurements J of the bactericidal power of the blood after 
 typhoid inoculations, and of the phagocytic power 2 of the blood 
 after staphylococcus-inoculations, the fact that the law of the 
 negative and positive phase governs the production of bacterio- 
 tropic substances just in the same way as it governs the 
 production of antitoxins (toxitropic substances). 
 
 Jofgensen and Madsen 3 adduced proof that the law of the 
 negative phase applied also to the formation of the agglutinins 
 of typhoid and cholera. 
 
 It was further shown by Morgenroth 4 in connection with 
 the development of anti-rennet in the organism, and by 
 Bulloch, 5 whose work was supplemented afterwards by the 
 researches of Sachs, 6 that the production of these antitropic 
 substances follows precisely similar lines. 
 
 1 " On the Changes effected by Anti-typhoid Inoculation in the Bactericidal 
 Power of the Blood." Lancet, Sept. 14, 1901. 
 
 2 " On the Treatment of Furunculosis, Sycosis, and Acne by the Inoculation 
 of a Staphylocccus Vaccine." Lancet, March 29, 1892. 
 
 3 Festskrift ved indvielsen af Statens Serum Instttut., Kopenhagen, 1902. 
 
 4 Centralblatt. f. Bakteriologie, 1899. 
 
 5 Trans, of Path. Soc. of London, 1901. 
 
 6 Archiv.f. Anat. u. Phys.. 1903.
 
 ANTI-TYPHOID INOCULATION. 
 
 ii 
 
 Thus by a series of successive extensions the law of the 
 positive and negative phase has revealed itself to be the law 
 which governs the production of antitropic substances generally* 
 It is, in other words, the general law of immunisation. 
 
 DEPENDENCE OF THE NEGATIVE PHASE UPON THE DOSE 
 OF THE VACCINE. 
 
 The intensity or the negative variation and the duration of 
 this phase of diminished antitropic substances in the blood is, 
 as I have been able to show in connection with the typhoid 
 and staphylococcic inoculations, directly dependent upon the 
 dose of vaccine administered. I have shown in the case of ariti- 
 
 Elision of the negative phase. Curve obtained by the author, 
 showing the content of the blood in bactericidal substances, in 
 the case of a patient inoculated with a small dose of anti-typhoid 
 
 vaccine. 
 
 Development of a prolonged negative phase. Curve obtained by 
 author, showing content of the blood in bactericidal substances 
 in the case of a patient inoculated with a large dose of anti- 
 typhoid vaccine.
 
 12 ANTI-TYPHOID INOCULATION. 
 
 typhoid inoculation that where very small doses are adminis- 
 tered that is to say, doses insufficient to set up appreciable 
 constitutional disturbance the positive phase is already fully 
 developed within twenty-four hours after the inoculation. A 
 very fugitive negative phase has, it may be noted, quite 
 recently come under the observation of Sachs in connection 
 with the immunisation of animals against foreign blood. The 
 curves which appear above illustrate respectively the elision 
 of the negative phase and the prolongation of that phase. 
 The differences here in question w^ere dependent on the 
 employment in the one case of a small, in the other of a large 
 dose of vaccine. 
 
 CUMULATIVE EFFECTS OF TWO OR MORE INOCULATIONS. 
 
 Of great practical importance in connection with resort to 
 repeated inoculation is a knowledge of the cumulative effect 
 produced of two or more successful inoculations. 
 
 Cumulation may take place in two opposite directions. 
 When in the case of two successive inoculations the second 
 falls upon the positive phase of the former inoculation, or, as 
 the case may be, on any period when the blood contains an 
 increased quantity of antitropic substances, there is developed a 
 cumulative high tide of immunity. 
 
 When, on the contrary, the second inoculation falls on the 
 negative phase of the first, cumulation takes place in the 
 direction of the negative phase. There is developed then a 
 condition of cumulative susceptibility.
 
 ANTI-TYPHOID INOCULATION. 
 
 Cumulative effects of two inoculations properly interspaced. 
 Curve obtained by the Author and Capt. W. Glen Liston, I. M.S., 
 setting forth the content of the blood in bactericidal substances 
 
 in the case of a rabbit inoculated with anti-typhoid vaccine. 
 In this and in the three preceding Curves the bactericidal power 
 which is charted represents the bactericidal power of in each 
 
 case i c.c. of freshly drawn serum. 
 
 The method employed was in each case the method described 
 by the Author (Proc. Royal Society, Vol. 71).
 
 ANTI-TYPHOID INOCULATION. 
 
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 hug Power 24 2g , 
 
 Limit-man 
 
 64dil" 
 
 32dilo 
 
 IBdil" 
 
 Body 
 Weight 
 
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 92ilbs. 
 
 93lbS 
 
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 Sv <- <i 
 
 S "w S3 '~ 
 
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 ANTI-TYPHOID INOCULATION. 15 
 
 CHAPTER II. 
 
 APPLICATION OF THE PRINCIPLES DEVELOPED ABOVE TO 
 THE PROBLEM OF THE PRODUCTION OF IMMUNITY 
 AGAINST TYPHOID FEVER. 
 
 IT has appeared in Chapter I. that every condition of immunity 
 is based upon the elaboration of antitropic elements in the 
 organism. Here \ve pass on to the practical question as to 
 how a condition of insusceptibility to typhoid infection may 
 be achieved. 
 
 Taking it as a working assumption that we can compass 
 our object only by inducing an elaboration of typhotropic 
 substances in the organism, and by the inoculation of a 
 vaccine prepared from a typhoid culture, our subject-matter 
 distributes itself naturally under three headings. We have to 
 ask ourselves : 
 
 (a) What kind of services we desire the typhotropic sub- 
 stances, which are to be called into being, to undertake in the 
 organism ; 
 
 () What form of culture, or what culture-derivative what 
 vaccine, in short will induce the organism to furnish the 
 antitropins which will be capable of undertaking the services 
 required ; 
 
 (c) What procedures we ought to adopt in connection with 
 the dosage, standardisation, and administration of the typhoid 
 vaccine. 
 
 Before embarking upon the consideration of the rirst 01 
 these questions it will be well to realise the following facts 
 with regard to the different ways in which antitropins may 
 render protective service to the organism : 
 
 1 i ) An antitropin may combine with the chemical element 
 to which it stands in antitropic relation we may hereafter 
 speak of every such element as a conjngin in such a manner as 
 to throw it out of solution. An antitropin which undertakes 
 this office is technically denoted a precipitm. 
 
 (2) In the case where the conjugin is a poisonous element, 
 the antitropin may combine with it in such a manner as to 
 deprive it of its toxicity. An antitropin which undertakes
 
 j6 ANTI-TYPHOID INOCULATION. 
 
 this office may, without reference to the derivation of its 
 poisonous conjugin, be denoted an antitoxin. 
 
 (3) In the case where the conjugin is a constituent of 
 a formed element, an antitropin may combine with it as to 
 cause the formed element to agglutinate when immersed in a 
 sufficiently strong salt-solution. 1 
 
 (4) An antitropin may, as I have recently shown in con- 
 junction with Captain Stewart Douglas, I. M.S.,' 2 modify the 
 particular formed element to which it stands in antitropic 
 relation in such a manner as to render it attractive pabulum 
 to the white blood-corpuscles. An antitropin which performs 
 this office may, as we have suggested, be denoted an opsonin. 
 
 (5) In the case where the conjugin forms one of the 
 constituent bonds in the " vital ring " of the protoplasm, the 
 combination of the antitropin with the conjugin may involve 
 the shattering of the whole chemical structure of the proto- 
 plasm. An antitropin which combines with its conjugin in 
 such a manner as to bring about this chemical disintegration 
 may, in the case where bacteria are the formed elements under 
 consideration, be spoken of as a bactericidal substance. 
 
 (6) An antitropin which disintegrates a complex molecule 
 in such a manner as to resolve it into soluble elements, is 
 technically denoted a lysin. When it brings into solution the 
 haemoglobin of the red blood-corpuscles, it is spoken of as a 
 hcemolysin. When it brings into solution the protoplasm of 
 bacteria, it is spoken of as a bacteriolysin. 
 
 (7) In the case where the conjugin forms a constituent bond 
 in the " vital ring " of the protoplasm, and where it further 
 constitutes, when set free, a poisonous element, the antitropin, 
 while it shatters the structure of the molecule by entering 
 into chemical combination with its conjugin, may at the 
 same time quench the toxic properties of that conjugin. An 
 antitropin which fulfils this double office is at one and the same 
 time a bactericidal substance and an antitoxin. 
 
 NATURE OF THE SERVICES WHICH WE DESIRE THE TYPHOID 
 ANTITROPINS TO UNDERTAKE IN THE ORGANISM. 
 
 What we desire from anti-typhoid inoculation is that it shall, 
 if possible, ward off the typhoid attack ; failing this, that it 
 
 1 Attention may be recalled in this connection to the fact that agglutinating 
 reactions manifest themselves only in the presence of salts. 
 - Proc Roy. Soc., Oct. 1903, and Feb. 1904.
 
 ANTI-TYPHOID INOCULATION. 17 
 
 shall at least mitigate that attack. The successful achievement 
 of the former object involves the devitalization of the typhoid 
 bacillus immediately upon its entry into the system of the 
 patient. The successful achievement of the latter involves the 
 devitalisation of the typhoid bacillus, as soon as may be, after 
 it has effected a lodgment in the system. For the attainment 
 of either the former or the latter purpose, the system must be 
 furnished with typho-tropic elements. 
 
 While the achievement of increased bactericidal power must 
 in all cases be the primary object of concern, it is legitimate, 
 as a secondary and subsidiary object, to aim also at the neutra- 
 lisation of the toxic elements of the bacterial protoplasm r 
 which are set free in the organism in the case where the 
 typhoid attack is not completely warded off. This contingency 
 will be provided for, if we can furnish the organism with 
 antitropins which will perform, in addition to the office of 
 devitalising the typhoid bacillus, also that of quenching the 
 poisonous properties of the elements of the bacterial protoplasm, 
 which pass into solution where the typhoid bacillus is broken 
 up in the organism. 
 
 QUESTION AS TO WHAT FORM OF CULTURE, OR WHAT 
 BACTERIAL DERIVATIVE, WILL INDUCE THE ORGANISM 
 TO FURNISH THE TYPHOTROPIC SUBSTANCES WHICH 
 ARE REQUIRED FOR THE PREVENTION AND MITIGATION 
 OF TYPHOID FEVER. 
 
 In order to induce the organism to furnish the bacteriotropic 
 substances which it will require when it is confronted by the 
 typhoid bacillus, we must, as consideration will show, introduce 
 into the body constituents of the protoplasm of the typhoid 
 bacillus, as distinguished from the metabolic products which 
 may have been elaborated by the micro-organism in the course 
 of its cultivation. 
 
 Having recognised that the vaccine employed for anti- 
 typhoid inoculation must contain constituents of the bacterial 
 protoplasm, we have still to decide in what particular form 
 these shall be administered. 
 
 In making our election between the different varieties of 
 vaccines which might be brought into application we may take 
 as our guide either tradition and a priori considerations, or, 
 
 B
 
 1 8 ANTI-TYPHOID INOCULATION. 
 
 emancipating ourselves from these, we may take as our guide the 
 data furnished by a qualitative and quantitative determination 
 of the antitropins which are elaborated in response to each 
 particular variety of vaccine. 
 
 If conformity to the practice adopted in the earliest preven- 
 tive inoculations were exacted, we should have to employ, as in 
 the case of the Pasteurian inoculations against anthrax, and in 
 the case of the anti-cholera inoculations of Haffkine which 
 were modelled upon the Pasteurian pattern cultures of living 
 attenuated microorganisms. It is unnecessary to point out that 
 such a course would in the case of the typhoid bacilli which 
 we are here considering entail grave risks : the risk of dis- 
 seminating the germ of the disease, and that of communicating 
 the disease in a serious form in any case where by mischance 
 the inoculated patient happened to be characterised by an 
 abnormal susceptibility to typhoid infection. 
 
 If, while discounting the Pasteurian principle of the necessity 
 of employing living micro-organisms, we were still to cling to the 
 view that every method which involves a chemical alteration 
 of the bacterial protoplasm is inadmissible, it would be neces- 
 sary to resort to devices for devitalising our bacteria without 
 exposing them to the action of heat or antiseptics. 
 
 Such a restriction would involve us in the grave incon- 
 veniences and risks which are associated with the proposed 
 method of Macfadyen. 1 It would, on the one hand, necessitate 
 resort to the complicated apparatus which is required for the 
 trituration of bacteria ; and, on the other hand, it would deprive 
 us of the security against contamination and against the risk 
 of communicating the typhoid infection, which is obtained 
 by the employment of cultures which have been devitalised 
 by heat. 2 
 
 If, lastly, we are prepared to accept evidence of the 
 production of the desired antitropic substances as proof of the 
 efficacy of the vaccine, we shall find ourselves, as the reader 
 
 1 Proc. Roy. Soc., 1903. 
 
 - It may be pointed out that the method of preparing typhoid vaccine which 
 has been suggested by Macfadyen is essentially the same as the method previously 
 employed by Koch in the preparation of his tubercle vaccine (new tuberculin) . 
 What has been said above with regard to the inconveniences and risks of 
 Macfayden's method applies therefore, mutatis mutandis, also to Koch's method 
 ot preparing tubercle vaccine.
 
 ANTI-TYPHOID INOCULATION. 19 
 
 will realise at the end of the next section, and again when we 
 come to deal with the statistics of anti-typhoid inoculation, 
 free to employ for our inoculations cultures which have been 
 sterilised by exposure to a temperature of 60 C. 
 
 It will be unnecessary to point out to anyone who has 
 experience of such matters the manifold practical advantages 
 which result from the employment of such sterilised cultures. 
 
 QUESTION AS TO WHETHER THE INOCULATION OF A 
 TYPHOID CULTURE WHICH HAS BEEN STERILISED BY 
 EXPOSURE TO TEMPERATURES OF 6o C. IS CAPABLE 
 OF INDUCING IN THE ORGANISM THE ELABORATION 
 OF THE TYPHOTROPIC SUBSTANCES WHICH ARE 
 REQUIRED. 
 
 I may appropriately open the consideration of this question 
 by pointing out that the suggestion that preventive inoculations 
 should be undertaken against typhoid fever upon the Pasteurian 
 system a suggestion which was originally made to me by 
 Mr. Haffkine was, considering the risk which seemed to me 
 to be involved in such a process, destined, so far as I was con- 
 cerned, to remain indefinitely inoperative. The whole aspect 
 of this suggestion was immediately changed as soon as I learned 
 in the course of conversation with Professor R. Pfeiffer that 
 he had in man obtained the specific agglutination-reaction to 
 typhoid by the subcutaneous inoculation of a heated typhoid 
 culture. This observation, since it pointed to the continued 
 presence of effective vaccinating elements in the heated culture, 
 immediately supplied the basis for the system of anti-typhoid 
 inoculation which I have employed. 1 
 
 In the course of the researches which have been carried 
 on by me, so far as time and opportunity have allowed, during 
 the last six and a half years, further evidence has accumulated 
 in my hands with regard to the integrity of the vaccinating 
 elements in typhoid cultures which have been subjected to the 
 action of heat. The facts may be grouped under two headings : 
 
 1 It may be observed that Professor Pfeiffer also recognised that his 
 observation with regard to the production of agglutinins by inoculation of 
 sterilised cultures had opened the way to anti-typhoid inoculation. The results 
 of two experimental anti-typhoid inoculations were published by him in con- 
 junction with Kolle (Deutsche Medic. Wochenschft., Nov. 12, 1896) shortly after the 
 publication of my first two anti-typhoid inoculations (Lancet, September 19, 1896). 
 
 E Z
 
 20 ANTI-TYPHOID INOCULATION. 
 
 (a) facts showing that the typhoid culture is unaltered so 
 far as its immunising properties are concerned by exposure 
 to the temperature which is required for the devitalisation of 
 the bacteria ; and () facts showing that the chemical rela- 
 tions which obtain between the protective substances of the 
 blood and the unheated typhoid bacillus, obtain also between 
 these protective substances and the typhoid bacillus after it 
 has been devitalised by exposure to a temperature of 60 C. 
 
 OBSERVATIONS WHICH SHOW THAT THE TYPHOID CULTURE 
 PRESERVES ITS VACCINATING EFFICACY AFTER EXPO- 
 SURE TO TEMPERATURES OF 6o-65 C. 
 
 The proposition that the typhoid culture preserves its vacci- 
 nating efficacy after exposure to a temperature of 60 C. is 
 established 
 
 (a) by the fact that the bactericidal power of the blood is 
 increased sometimes as much as one-thousandfold as the 
 result of a single inoculation of a suitable quantum of a sterilised 
 typhoid culture ; l 
 
 () by the fact that an increased bacteriolytic power if 
 developed in the blood of patients who have been inoculated 
 with a suitable quantum of such sterilised typhoid cultures ; - 
 
 (c) by the fact that a patient who has recovered from a first 
 inoculation of a sterilised typhoid culture does not upon second 
 inoculation suffer from the very severe constitutional intoxi- 
 cation which would supervene in the case of an uninoculated 
 person inoculated with this dose of typhoid vaccine. 
 
 (d) by the fact that an increased opsonic power is 
 developed in the blood of patients who have been inoculated 
 with a suitable quantum of sterilised typhoid culture. 
 
 We have in (a) and () evidence of the elaboration of 
 antitropins which exert a destructive effect on the typhoid 
 
 1 Author's paper, Lancet, September 14, 1901. 
 
 2 This may be demonstrated by making a series of progressive dilutions of the 
 serum of a normal and of a vaccinated person, and mixing in each case the 
 successive dilutions of serum with equivalent volumes of culture in a capillary 
 tube. On examining microscopically films made with the contents of the 
 capillary tube after the serum has been allowed to act upon the bacteria for half 
 an hour at blood-heat, it will be found that the bacteriolytic effect has manifested 
 itself in a much higher dilution in the case of the serum obtained from the 
 inoculated patient, than in the case of the serum obtained from a normal person 
 who acts as control.
 
 ANTI-TYPHOID INOCULATION. 21 
 
 bacillus ; in (c) evidence of the elaboration of antitropins which 
 discharge the office of antitoxins, and in (d) evidence of the 
 elaboration of opsonic antitropins. 
 
 Summarising the above, we see that inoculation of cultures 
 of typhoid bacilli which have been sterilised by exposure 
 to a temperature of 60 C. induces in the organism an elabo- 
 ration of 
 
 (a) Agglutinating antitropins 
 
 () Bactericidal antitropins ; 
 
 (c) Bacteriolytic antitropins ; 
 
 (d) Antitoxic antitropins ; 
 
 (e) Opsonic antitropins. 
 
 OBSERVATIONS WHICH SHOW THAT THE CHEMICAL RELA- 
 TIONS WHICH OBTAIN BETWEEN THE TYPHOTROPIC 
 SUBSTANCES OF THE BLOOD AND UNHEATED TYPHOID 
 CULTURES OBTAIN ALSO BETWEEN THESE SUBSTANCES 
 AND TYPHOID CULTURES WHICH HAVE BEEN EXPOSED 
 TO A TEMPERATURE OF 6o-65 C. 
 
 The evidence under this heading is furnished by the fact 
 that the agglutinating and bacteriolytic effects which are 
 exerted upon living typhoid cultures by the typhotropic sub- 
 stances of the blood, are exerted also, but in a somewhat 
 diminished degree, upon typhoid cultures which have been 
 sterilised by exposure to a temperature of 60 C. 
 
 In sharp contrast with what occurs when the serum is 
 
 brought into contact with cultures which have been sterilised 
 
 at 60 C. is the entire absence of bacteriolysis in the case of 
 
 'cultures which have been heated to 72 C. before exposure to 
 
 the action of the serum. 
 
 CONCLUSIONS WHICH CAN BE DRAWN FROM THE EVIDENCE 
 FURNISHED UNDER THE TWO PRECEDING HEADINGS. 
 
 The concordant observations which have been set forth 
 in the two preceding sections establish in a very clear manner 
 that the vaccinating elements in the typhoid culture are 
 maintained practically intact after exposure to a temperature 
 of 60 C. 
 
 It is interesting to bring into relation with the experimental . 
 data with regard to the typhoid bacillus which have been
 
 22 ANTI-TYPHOID INOCULATION. 
 
 set forth above, certain experimental data relative to the red 
 blood-corpuscles which have just been placed at my disposal by 
 my friend Dr. Bulloch. In the course of experimentation upon 
 the effect exerted by temperature upon the elements in the red 
 blood-corpuscles which induce an elaboration of haemolytic 
 antitropins in the animal organism, it has been observed by 
 Dr. Bulloch that the efficacy of these vaccinating elements is 
 preserved, though it is somewhat diminished, by exposure to a 
 temperature of 60 C. Exposure to a coagulating temperature 
 of 72 C. and it will be noted that this is the same as that 
 referred to in the last section in connection with experiments 
 upon the typhoid bacillus completely abolishes the immu- 
 nising properties of the red blood-corpuscle. 
 
 DIFFICULTIES WHICH STAND IN THE WAY OF THE RESO- 
 LUTION OF THE QUESTION AS TO WHAT FORM OF 
 ANTI-TYPHOID VACCINE IS ABSOLUTELY THE BEST. 
 
 It will round off what has been said above in connection 
 with the choice of a typhoid vaccine if I point out here that 
 the problem as to what is the absolutely best anti-typhoid 
 vaccine is a question to which the answer will be obtained 
 only after very long and laborious experimentation. The 
 sources of fallacy which are incident to an experimental inves- 
 tigation of the question may be brought before the reader's 
 mind by the following analogy. While the character of the 
 harvest constitutes conclusive proof that the proper variety 
 of seed has been chosen, the fact that in a particular case the 
 harvest has been plentiful, and has been specially rich in 
 certain elements, does not constitute demonstration of par- 
 ticular virtues in the seed. The special character of the soil, 
 the methods followed in the sowing, are capable of exerting a 
 very sensible effect. In the same manner, the harvest of anti- 
 tropins which is reaped in any particular instance will be 
 influenced by the individual idiosyncrasy of the patient, and 
 by the system of dosage which has been adopted. It must 
 therefore be reserved for the future to determine whether 
 the simple sterilised typhoid culture, such as I employ, consti- 
 tutes the ideally-best anti-typhoid vaccine. For the present 
 we must content ourselves with the fact that sterilised typhoid 
 cultures have been shown to constitute a vaccine which will
 
 ANTI-TYPHOID INOCULATION. 23 
 
 induce elaboration of the special varieties of anti-tropins that 
 are required for the protection of the organism against typhoid. 
 It will presently emerge that the practical efficacy of the vaccine 
 is borne out in a very distinct manner by the statistical records 
 that set forth the results obtained by the actual practice of 
 typhoid inoculation. 
 
 BRIEF ACCOUNT OF THE METHOD OF MAKING THE 
 REQUIRED MASS-CULTURES OF THE BACILLUS TYPHOSUS 
 AND PROCEDURES (A) FOR TESTING THE PURITY 
 OF THESE CULTURES ; (B) FOR STERILISING ; AND (c) 
 FOR DECANTING THEM WITHOUT RISK OF CONTAMI- 
 NATION. 
 
 The detail of the technique which has been employed for 
 obtaining a pure and perfectly sterile typhoid vaccine is reserved 
 for the Appendix. It will suffice here to note that the descrip- 
 tion of the procedures which was given ' by me in conjunction 
 with my sometime colleague, Major W. B. Leishman, 
 R.A.M.C., and which will be found reproduced in Appendix I., 
 have stood the severe test which was imposed upon them by 
 the demand for 400,000 doses of anti-typhoid vaccine which 
 arose in connection with the South African campaign. 
 
 Evidence of the adequacy of the measures taken to secure 
 the sterility of the vaccine is afforded by the fact that when, 
 after the war, the unused vaccine was returned to store at 
 Xetley, the untouched bottles, so far as they were examined, 
 were in every case found to be sterile. Perhaps even more 
 satisfactory evidence of the adequacy of the system of technique 
 which was employed is afforded by the fact that no case of 
 septic trouble complicating inoculation was reported in connec- 
 tion with the inoculations undertaken in the course of the war. 
 These inoculations may perhaps have numbered somewhere 
 about 100,000. 
 
 STANDARDISATION OF THE VACCINE. 
 
 It is necessary to distinguish between standardisation and 
 dosage ; and it will be convenient to deal first with the former. 
 Standardisation has for its object the determination of the 
 
 1 Brit. Med. Journal, Jan. 20, 1900.
 
 24 ANTI-TYPHOID INOCULATION. 
 
 strength of one vaccine in terms of another vaccine, the dose of 
 which has been determined by experiments undertaken upon 
 man. 
 
 The following are the systems of standardisation which have 
 from time to time been employed : 
 
 (a) In the earliest inoculations, conducted in conjunction 
 with Lieut.-Col. D. Semple, R.A.M.C., the virulence of the 
 culture was in the first instance elicited by determining the 
 fatal dose of that culture inoculated living into guinea-pigs of 
 a standard weight of 250 grammes. The amount of sterilised 
 vaccine employed for the inoculation was then adjusted in 
 such a manner as to stand in relation with the amount of 
 agar-culture which constituted the fatal dose for 100 grammes 
 of guinea-pig. 
 
 (b) In the case of most of the vaccine sent out in connection 
 with the South African war, a double process of standardisation 
 was adopted. The toxic effect of the completed vaccine ! was 
 elicited upon a series of guinea-pigs. As a further control the 
 opacity of the vaccine was measured by means of a simple and 
 ingenious piece of apparatus devised for this purpose by my 
 colleague, Major Leishman, R.A.M.C. 2 
 
 Neither of these last-mentioned tests was completely 
 satisfactory. It was found that the resistance of the guinea-pig 
 to the toxic effects of the vaccine was an extremely variable 
 factor, also that the measurement of the opacity was occasion- 
 ally vitiated by autolytic processes which took place in the 
 course of the cultivation. Thus it became advisable and this 
 was carried out wherever practicable to control the tests 
 which have just been described by the determination of the 
 toxic effect exerted by the vaccine upon man. In particular it 
 was found desirable to do this in the case where a typhoid 
 culture which had been cultivated for prolonged periods on 
 artificial media was replaced by a typhoid culture recently 
 isolated from the organism. 
 
 (c) For the methods of standardisation described above I 
 have recently substituted a much more satisfactory method. 
 I now elicit the number of bacilli contained in the culture by 
 
 1 This now consisted of a sterilised and carbolised broth-culture, which had 
 been cultivated for 10 to 21 days. 
 
 2 Figured in a paper by the author and Major Leishman, Brit. Med. Journ., 
 January 30, 1900.
 
 ANTI-TYPHOID INOCULATION. 25 
 
 enumeration 1 under the microscope. With a view to forestalling 
 autolysis I have recently employed in every case 24-hour 
 cultures. Again, in order to avoid the source of disturbance 
 which is associated with the change of culture and with a view 
 to facilitating enumeration, I now employ exclusively a strain 
 of the typhoid bacillus which yields within a 24-hour limit 
 of growth, under favourable circumstances, cultivations contain- 
 ing from 1,000 to 2,000 or more millions of bacilli in the cubic 
 centimetre. 
 
 DOSAGE OF ANTI-TYPHOID VACCINE. 
 
 IT will be manifest that the question as to what quantum of 
 vaccine constitutes an appropriate dose is a question which can 
 be determined only by the method of trial and error, i.e., by 
 the method of giving a series of graduated doses to a series of 
 different individuals and selecting for employment the quantum 
 which is found to be most appropriate. 
 
 In connection with the determination of the most appro- 
 priate dose, we may guide ourselves by reference to the clinical 
 symptoms developed and in particular to the height of the 
 temperature reaction. Or alternatively we may guide ourselves 
 by reference to quantitative estimations of the content of the 
 blood in antitropic substances. 
 
 In taking the clinical symptoms as a guide we are liable in 
 the present state of our knowledge to fall into grave error. 
 
 (a) We may, for instance, in the case where an inoculation 
 has failed to induce a temperature-reaction, draw from this 
 fact the inference that the inoculation has been entirely 
 unprofitable. Such an inference may be altogether erroneous. 
 An elaboration of antitropins may in my experience occur 
 quite independently of any temperature-reaction or other 
 constitutional disturbance. 
 
 (b) We may fall into the error of believing that the more 
 severe the constitutional reaction and the higher the fever, the 
 greater must be the quantum of antitropins developed. Such 
 an inference would be altogether erroneous. In point of fact 
 very severe constitutional reaction is often associated with a 
 
 1 The method of enumeration here referred to is that published by me in the 
 Lancet for July 5, 1902. It is described in Appendix I.
 
 26 ANTI-TYPHOID INOCULATION. 
 
 prolonged impoverishment of the blood in protective sub- 
 stances. I have had experience of this in my own person in 
 connection with the inoculation of a large dose of anti-typhoid 
 vaccine. The observation made by Dr. Tooth in South Africa 
 to the effect that a severe constitutional reaction had occurred 
 in many of the inoculated who afterwards contracted typhoid 
 fever, points in the same direction. 
 
 (c) When we have realised that the inference referred to 
 under (a) is unwarranted, we may fall into the contrary error 
 of assuming that a condition of immunity is being achieved 'in 
 cases where the absence of constitutional reaction is in reality 
 imputable to the inoculation of a defective vaccine or a 
 deficient quantity of vaccine. 
 
 (d) When we have realised that the inference referred to 
 under (/>) is unwarranted, we may fall into the contrary error 
 of inferring from the absence of fever that the quantum of 
 vaccine which is being inoculated in a series of successive 
 doses is not excessive. In the case set forth (Chart, page 14) 
 there was nothing in the temperature to suggest that a 
 cumulative negative phase was being induced. 
 
 We cannot safeguard ourselves against error in the dosage of 
 vaccine except by making, after inoculation, a systematic series 
 of blood-examinations upon the patients. In connection with 
 experiments undertaken for the purpose of fixing the optimum 
 dose or, as the case may be, doses of a vaccine, difficulties 
 will present themselves which are in all respects similar to 
 those which were under discussion on page 22 in connection 
 with the question of the selection of the absolutely best vaccine. 
 
 These difficulties might perhaps be overcome in the case 
 of a regiment or similar aggregate of men, by dividing it up 
 into a number of batches, by inoculating ( each batch with a 
 different quantum of the vaccine, and then constructing for each 
 batch a curve representing the average course ot the reaction 
 of immunity in the batch. Such curves could be obtained 
 by determining upon the pooled l blood of each separate 
 group, the bactericidal, bacteriolytic, and agglutinating power 
 which had been developed in the course of the reaction of 
 
 1 Such pooled blood would be readily obtained by withdrawing, say, 50 cmm. 
 of blood from each individual, and mixing these measured quanta.
 
 ANTI-TYPHOID INOCULATION. 27 
 
 immunisation. Having selected, after the consideration of the 
 curves of immunisation thus obtained, the optimum dose or, 
 as the case might be, doses of vaccine, it would be possible, 
 given a perfect method of standardisation, to arrive without 
 any further experimentation at the dose of any other typhoid 
 vaccine which came to hand. Pending opportunity for carry- 
 ing out such an experiment as that above described, I now 
 employ in the case of the first inoculation a quantum of 
 vaccine containing 750 to 1,000 millions of typhoid bacilli, and 
 for the second inoculation a quantum of vaccine containing 
 1,500 to 2,000 millions of the same bacilli. I find that the 
 inoculation of these quanta induces an ample elaboration of 
 antitropic substances without producing any severe constitu- 
 tional reaction. 
 
 QUESTION OF THE POSSIBILITY OF INTRODUCING THE 
 VACCINE IN AN EFFECTIVE MANNER INTO THE 
 ORGANISM BY THE CHANNEL OF THE ALIMENTARY 
 CANAL. 
 
 In view of the considerable local pain which is induced by 
 anti-typhoid inoculation, it is natural to enquire whether there 
 -may not be some method other than that of subcutaneous 
 inoculation by which the vaccine may be introduced into the 
 body. I was induced by a communication received from 
 Captain C. E. Pollock, R.A.M.C., to take up again, in conjunc- 
 tion with Captain W. Glen Liston, I. M.S., in the summer of 
 1902, an investigation on this point which I had begun at an 
 earlier date. This time my experiments were destined to be 
 closured by the transference of the Army Medical School to 
 London. 
 
 The gleanings from these experiments, which are set out in 
 the curves on pp. 29 and 30, have, if I mistake not, at least 
 a certain suggestive value. 
 
 Experiment i. The experiment here in question was under- 
 taken upon Mr. F., a Surgeon on Probation in attendance on 
 the Army Medical School, Captain W. Glen Liston, and myself. 
 Mr. F. was a normal uninoculated man ; Captain Liston had 
 undergone anti-typhoid inoculation some two years before the 
 date of the experiments ; and I myself had on three occasions 
 inoculated myself with anti-typhoid vaccine. The last of these
 
 28 ANTI-TYPHOID INOCULATION. 
 
 inoculations had been undertaken some 15 months before the 
 date of the experiment. 
 
 The experiment was begun on June ist by our drinking in 
 each case i cc. of a typhoid vaccine, the dose of which had been 
 fixed for the purposes of subcutaneous inoculation at i cc. On 
 June 6th we drank a further 5 cc. of the vaccine, and on June 8th 
 a further 15 cc. 
 
 Captain Listen and I did not suffer in any way from the 
 inoculations beyond perhaps a little malaise. Mr. F. ; who was, 
 it will be remembered, uninoculated, suffered from diarrhoea and 
 considerable constitutional disturbance after imbibing the final 
 dose of 1 5 cc. 
 
 The observations made with regard to changes in the content 
 of the blood in bactericidal substances are set forth in the curve 
 on next page. 
 
 Commencing with the lowest of the three curves which 
 represents the effect exerted upon Mr. F.'s blood, it will be 
 seen that the ingestion of the anti-typhoid vaccine was followed 
 by a very remarkable decline in the bactericidal power of the 
 blood. We may most naturally interpret this as a negative 
 phase similar to the negative phases which are produced by 
 the subcutaneous inoculation of large doses of typhoid vaccine. 
 
 Passing to the middle curve, which represents the change 
 that occurred in the bactericidal power of Captain Listen's 
 blood, we see indications of the development of a moderate 
 positive phase. Upon this supervenes a decline, followed again 
 by a positive phase and a second decline. We may suppose 
 that there was here some irregularity in the absorption of the 
 vaccine from the alimentary canal. 
 
 In the case of the upper curve, which sets forth on a 
 threefold-diminished scale the changes which occurred in the 
 bactericidal power of my own blood, we have evidence or 
 the production of a very striking positive phase, which was 
 followed by a typical decline. It is interesting to note that 
 this curve gives, so far as it goes, countenance to the sugges- 
 tion made in Chapter I. (page 8, paragraph 4) that anti-typhoid 
 inoculation may confer upon the organism a greater power of 
 response to any renewal of the vaccinating stimulus. 
 
 Experiment 2. In the experiment here in question foui 
 Surgeons on Probation each drank 10 cc. of the same typhoid
 
 ANTI-TYPHOID INOCULATION. 
 
 29 
 
 ~ S' 
 
 .jf 
 
 ^ r " 
 
 s i 
 
 ^ 4j" -" 
 
 ^5 7 f 
 
 -. J. u , 
 
 ^S O O _C 
 
 * S^ 3^3 
 
 3 -S a, m 
 
 ^ % '* * L- 
 
 'Z *3 $ 
 
 w 
 
 * .5 * 
 
 J 1) 
 
 III 
 
 w 2 w 
 
 O
 
 ANTI-TYPHOID INOCULATION. 
 
 vaccine which was employed in Experiment i. It will be 
 seen, on reference to chart below, that in the case of two of 
 these gentlemen a positive phase of very short duration was 
 obtained. In the case of the other two gentlemen a negative 
 phase only was achieved. 
 
 Bactericidal flower 
 of 
 
 16 17 ./A. 19 2.0 21 22 23 
 
 Curve obtained by the author in conjunction with Capt. W. 
 Glen Listoh, I. M.S., setting forth effects exerted on the blood of 
 four unmoculated men by the ingestion of anti-typhoid vaccine 
 
 by the mouth. 
 
 Experiment 3. In the case of this experiment 40 cc. or 
 the same typhoid vaccine was administered to each of two 
 rabbits. The chart on the next page brings before the eye the 
 result of this experiment. 
 
 We may surmise that the absence of negative phase may 
 here stand in some relation to the resistance which the rabbit 
 offers to typhoid infection.
 
 ANTI-TYPHOID INOCULATION. 
 
 3 1 
 
 Summary. While the experiments on uninoculated persons 
 set forth above do not seem to promise much in the way of 
 immediate practical utility, it will be clear that the series of 
 experiments suggests that the phenomenon of immunisation by 
 acclimatisation, which is so strikingly exemplified by the statis- 
 tical records of the British Army in India, may possibly be the 
 result of an occasional ingestion of the typhoid bacillus into the 
 alimentary canal. 
 
 Effect exerted on the blood of two rabbits by the introduction 
 of anti-typhoid vaccine by the month.
 
 32 ANTI-TYPHOID INOCULATION. 
 
 QUESTION OF THE POSSIBILITY OF ACHIEVING PROTECTION 
 APART FROM THE PRELIMINARY INDUCTION OF A 
 NEGATIVE PHASE. 
 
 We have seen above in considering the general law which 
 governs the elaboration of protective substances in the organism 
 that there supervenes upon the inoculation of a vaccine into the 
 organism in every case a negative phase. 
 
 It is not going too far to say that where the negative phase 
 does not appear upon the curve of immunisation this is due 
 either to too tardy examination of the blood, or to the fact that 
 a dimunition of immunising elements in the blood cannot, by 
 the nature of the case, be demonstrated where the blood 
 contains at the date of inoculation only mere traces of the 
 immunising elements in question. 
 
 We may take it as practically certain that under the con- 
 ditions last referred to, it would be possible in every case 
 given that the methods for demonstrating its presence were 
 available to detect the vaccine in the circulating blood for 
 a shorter or longer period after inoculation. 
 
 Such evidence has been obtained (a) in the case where the 
 vaccine employed is characterised by well-marked toxic pro- 
 perties, (b) in the case where the vaccine can be detected by 
 its specific power of reacting with a precipitating antitropin. 
 
 In the former case l toxic effects have been obtained in men 
 and animals by the administration of serum drawn off from 
 animals previously inoculated with various bacterial cultures or 
 their derivatives tuberculin, cultures of staphylococcus, strepto- 
 coccus, micrococcus melitensis, &c., &c. 
 
 In the latter case a the vaccine has, after inoculation, been 
 detected in the blood by the specific test. This has been done 
 in particular by Von Dungern in connection with his injections 
 of crabs' blood into rabbits. 
 
 It would seem clear, in the light of these further facts, that 
 the negative phase in the curve of immunisation corresponds 
 
 1 Vide Author's lecture (Brit. Med. Journal, May 9, 1903) on " Therapeutic 
 Inoculations of Bacterial Vaccines ;" in particular vide the section dealing with 
 the " Practical Importance of the Law of the Negative and Positive Phase In 
 connection with the Therapeutic Inoculation of Sera derived from Animals 
 vicariously inoculated with Bacterial Vaccines." 
 
 * Vide Von Dungern, Die Antihorper, pp. 81 and seq., and his illustrative 
 charts.
 
 ANTI-TYPHOID INOCULATION. 33 
 
 to a period of stimulation, just as the positive phase corresponds 
 to the period of maximum response to that stimulation. 
 
 This once recognised, it will immediately be apparent that 
 it will be as vain to expect to achieve a positive without a 
 negative phase as to expect response without stimulation. It 
 will be furthermore apparent that every suggestion which is 
 directed to the abolition of the negative phase is a suggestion 
 which involves as its corollary the assumption that a general 
 physiological principle can be set aside. 
 
 These general principles having been elucidated, we may 
 pass to consider the suggestions which Calmette and Besredka 
 respectively have put forward in connection with the procedure 
 of preventive immunisation. 
 
 The suggestion of Calmette has special reference to pre- 
 ventive, inoculation against plague. It was to the effect that 
 the serum of an animal which had been vicariously inoculated 
 should be introduced into the organism of the patient at the 
 same time as the bacterial vaccine. This suggestion here in 
 question was based upon the three following premisses : 
 
 (i.) Upon the premiss that protection is not acquired after 
 the inoculation of bacterial vaccines until a period of fifteen 
 days has expired. 
 
 (2.) Upon the premiss that the incorporation of serum from 
 an animal which has been vicariously inoculated confers upon 
 the patient a protection against bacterial invasion which lasts 
 fifteen days. 
 
 (3.) Upon the premiss that it is possible to superimpose 
 a condition of active immunity derived from the inoculation 
 of a bacterial vaccine upon a condition of passive immunity 
 derived from the incorporation of a serum in the manner in 
 which a curve referring to an active immunisation can be 
 mechanically superimposed upon a curve referring to a passive 
 immunisation. 
 
 With regard to the first and second of these premisses, it 
 will suffice to point out that abstract propositions such as these 
 have no general applicability, and that they may be and in 
 point of fact are, as will be seen on referring to the curves of 
 immunisation set forth in Chapter I. quite out of conformity 
 with the actual facts. 
 
 c
 
 34 ANTI-TYPHOID INOCULATION. 
 
 With regard to premiss No. 3, the following points may be 
 noted : 
 
 (.) Inasmuch as the antitropic substances introduced 
 in the serum of the vicariously inoculated" animal would 
 inevitably quench the chemical activity of the vaccine, we 
 have no right to expect from the organism a response such as 
 is obtained upon the introduction of a chemically active 
 vaccine. 
 
 (.) It has been shown by Jorgensen and Madsen ' in con- 
 nection with the production of typhoid agglutinins in the 
 organism of animals that a combination of active with passive 
 immunisation defeats its own object. 
 
 Two of the instructive curves which accompany Jorgensen 
 and Madsen's paper are reproduced on pp. 35 and 36. 
 
 In a direct line of affiliation to the suggestion of Calmette 
 is the suggestion of Besredka. 2 The suggestion of Besredka 
 is that the bacterial vaccines which are employed in con- 
 nection with anti-typhoid inoculation and in connection with 
 other inoculations, should in each case be digested in vitro with 
 sera obtained from vicariously inoculated animals, the surplus 
 of serum being in each case removed from the vaccine by 
 centrifugalisation and washing. It will be seen that this 
 suggestion involves on the one hand a serious complication of 
 the technique, and on the other hand a quenching of the 
 chemical activity of the vaccine similar to that which is involved 
 in the suggestion of Calmette. 
 
 Before dismissing the subject-matter of this negative phase 
 it may be re-emphasised that, while the injection of a bacterial 
 vaccine must in all cases be followed by a negative phase, that 
 negative phase can at all times be regulated by apportioning the 
 dose of the bacterial vaccine. 
 
 1 Loc. cit. 
 
 2 Annales de I'lnstitut Pasteur, 1902 ; Comptes Rendus de I'Academie des Sciences, 
 June 20, 1902.
 
 ANTI-TYPHOID INOCULATION. 
 
 35 
 
 22 
 
 27 
 
 32 
 
 37 
 
 42 45 123 6 
 
 37 40 
 
 Curve obtained by Jorgensen and Madsen, 1 showing, in the case 
 of a goat, (a) the effect of superimposing an injection of a bacterial 
 vaccine upon a passive (serum) immunisation, and (b) the effect of 
 an injection of a bacterial vaccine undertaken after the expiration 
 of the passive immunity. 
 
 Festskrift vtd Indvielsen a/Staiens Serum Institut, Kofenhagen, 1902. 
 
 c 2
 
 -1 
 
 'nj action 
 
 '-"^injection 
 
 of S cc 
 
 of 5 d 
 
 "^{njectic 
 
 broth 
 
 broth 
 
 'njectiori of typho-agglutinatirig serup 
 
 cultiva 
 
 oftyp 'to - Agglutinating serum. 
 
 cultivation 6f Bac. Typhosus 
 
 tion or Bac. Typhosu 
 
 Curve obtained by Jorgensen and Madsen (loc. cit.) showing, in the 
 case of rabbits, (a) the march of events after the injection of serum 
 from a vicariously inoculated animal ; (b) the effect of superimposing 
 an injection of a bacterial vaccine upon a passive immunisation ; 
 (c) the effect of an injection of a bacterial vaccine undertaken 
 after the expiration of the passive immunity conferred by the 
 
 scrum-injection. 
 
 NOTE. For convenience of representation the agglutination curve is shown as 
 reaching a climax in a sharp beak on the 55th day of the experiment. In reality 
 a higher but undetermined level was reached between the 55th and 6oth day.
 
 ANTI-TYPHOID INOCULATION. 37 
 
 CHAPTER III. 
 
 ON THE TECHNIQUE OF ANTI-TYPHOID INOCULATION, AND 
 ON THE CLINICAL SYMPTOMS WHICH SUPERVENE UPON 
 THE INJECTION OF THE VACCINE. 
 
 Having explained in Chapter I. the general principles of the 
 physiology of immunisation so far as those principles have 
 disclosed themselves to research, and in Chapter II. the applica- 
 tion of these principles to the problem of immunisation against 
 typhoid fever, we may here take up the consideration of the 
 technique of anti-typhoid inoculation and of the clinical 
 symptoms which follow inoculation. 
 
 ON THE TECHNIQUE OF ANTI -TYPHOID INOCULATION. 
 
 In connection with the technique of inoculation we have 
 to consider the sterilisation of the syringe, the method of 
 drawing off the vaccine from the containing vessel, and the 
 selection and preparation of the site for inoculation. Printed 
 instructions with regard to these points have in every case been 
 issued along with the vaccine. These may be summarised as 
 follows : 
 
 (a) Sterilisation of the Syringe. I have recommended that 
 the syringe should in all cases be sterilised by filling it with 
 oil heated to a temperature of about i4OC. I have pointed 
 out that a piece of bread-crumb furnishes a convenient thermo- 
 meter the bubbling off of the steam indicating a temperature 
 of over 100 C., and the browning of the bread-crumb after 
 the steam has been driven off a temperature of i4OC. Where 
 laboratory conveniences are not at hand, the oil with the 
 bread-crumb thermometer may be conveniently heated in a 
 tablespoon over an ordinary spirit-lamp. It is probably super- 
 fluous to point out that the filling of the syringe with oil at 
 i4OC. secures instantaneous sterilisation. 
 
 (b) Method of drawing off the Vaccine. In the case where 
 the vaccine is contained in a capsule, the point of this latter
 
 38 ANTI-TYPHOID INOCULATION. 
 
 is, after sterilisation in the flame, to be broken off with a 
 sterile instrument. The capsule having been inverted over the 
 needle of the syringe, its contents may be withdrawn in an 
 aseptic manner. In the case where the vaccine is sent out in 
 a bottle covered in an air-tight manner by an india-rubber cap, 
 the surface o'f the cap is conveniently sterilised by hot oil 
 carried to it by the syringe. The vaccine may then be drawn 
 off by puncturing through the rubber. 
 
 (c) Choice and preparation of the site of Inoculation. It is 
 advisable, with a view to avoiding the pain caused by the 
 tension of the serous effusion which takes place at the point 
 of inoculation, to insert the vaccine into a portion of the body 
 where the skin is loose. The back of the shoulder and the 
 flank are convenient situations. A fold of skin in one or 
 other of these regions is picked up between finger and thumb, 
 and the needle, after sterilisation of the skin with undiluted 
 lysol, is carried down well into the loose subcutaneous tissue in 
 the centre of this fold. 
 
 ON THE CLINICAL SYMPTOMS WHICH SUPERVENE UPON 
 THE INJECTION OF THE VACCINE. 
 
 The character and the severity of the train of symptoms 
 which supervene upon inoculation stand in relation with the 
 dose of the vaccine administered. This is to be understood 
 however with certain reserves. In the first place, it holds true 
 only when we are comparing different doses of the vaccine 
 made from one and the same strain of typhoid. In the second 
 place, it probably no longer holds true after a certain limit of 
 dose has been reached. I have, for instance, had it reported to 
 me that the accidental inoculation (on a transport proceeding 
 to South Africa) of tenfold the prescribed dose did not induce 
 any greater effect than that which was induced by the inocu- 
 lation of the already large dose actually prescribed. 1 
 
 The clinical symptoms which supervene after anti-typhoid 
 inoculation may be classed under the heading of () local 
 
 1 This last point is theoretically of great interest, indicating, as it does, that 
 the poisonous toxic elements in the vaccine, which evoke an elaboration of 
 aiuitropic substances, combine with the cells of the organism in quite a different 
 manner from the alkaloidal poisons. The effect of these last is in all cases 
 proportional to the dose administered.
 
 ANTI-TYPHOID INOCULATION. 39 
 
 symptoms, i.e., symptoms at the site of inoculation ; and () 
 constitutional symptoms. 
 
 Generally speaking, the severity of the local symptoms in 
 cases of first inoculation is inversely as the severity of the 
 constitutional symptoms. In cases where very severe consti- 
 tutional symptoms have been produced, I have seen the local 
 symptoms conspicuously absent. 
 
 Again, whereas in the case of the first inoculation consti- 
 tutional symptoms have been well marked, second inoculations 
 are frequently followed by nothing more than local symptoms. 
 
 Local Symptoms. Where a suitable quantum of anti-typhoid 
 vaccine, made from a suitable strain of typhoid bacillus, has been 
 injected the local symptoms first make themselves felt after an 
 interval of two or three hours. The effects then seen are the 
 development of a red blush and more or less serous exudation 
 at the seat of inoculation, followed by some lymphangitis along 
 the lymphatics which lead, according as the vaccine has been 
 inoculated above or below the middle line of the trunk, in 
 the direction of the glands of the axilla or of the groin. In a 
 case where a very toxic vaccine was employed, distinct local 
 effects supervened in a quarter of an hour, the congestion 
 around the site of inoculation afterwards assuming an almost 
 erysipelatous intensity. Even such severe inflammation has 
 never led on to suppuration. 
 
 It is a point of interest in connection with the pathology 
 of the serous haemorrhage which occurs at the site of injection 
 that the coagulability of the blood is diminished in a very 
 conspicuous manner as the result of anti-typhoid inoculation. 
 The diminution is already very well marked within two or three 
 hours after the incorporation of the vaccine. 
 
 With a view to counteracting the tendency to serous 
 haemorrhage at the seat of inoculation I have suggested the 
 administration of 30 or 40 grains of calcium chloride. The 
 restraining influence exerted by calcium chloride in these cases 
 is analogous to that which I have shown it to exert upon 
 the serous haemorrhage of chilblains 1 and of certain forms 
 of urticaria.' 2 
 
 1 Authors paper, Lancet, January 30, 1897. 
 
 2 Author's papers, Brit. Joiirn. of Dermatology, Vol. VIII., No. 89; Lancet, 
 September 19, 1896 ; and Transactions of Pathological Society, Vol. 51, Part III., 1900.
 
 40 ANTI-TYPHOID INOCULATION. 
 
 Another point which has an importance in connection 
 with the restraint of the effusion at the site of the inoculation 
 is the circumstance that the ingestion of alcohol, or of any 
 other substance which like alcohol 1 diminishes the coagula- 
 bility of the blood, increases serous haemorrhage and aggravates 
 the local pain, or, as the case may be, brings it back after it has 
 disappeared. Confirmation of my observations with regard to 
 this point has reached me from many different quarters. I may 
 point out that this increased serous exudation in the tissue 
 which has been chemically injured by inoculation is in every 
 way analogous to the exaggerated serous and actual haemor- 
 rhage which is so familiar a feature in connection with 
 mechanical injuries received in the condition of alcoholic 
 intoxication. 
 
 Passing from the consideration of the causes which influence 
 the serous haemorrhage to the question of the treatment of the 
 pain which is referable to it, attention may be drawn to the 
 fact that it is greatly relieved by the application of warm stupes 
 and by inunction with the following ointment : 
 
 $> Acidi Carbolici - - gr. xx. 
 
 Extract. Ergot. Liquid. - - 5 iss 
 
 Zinci Oxidi - 51 
 
 Lanolin - - 3 i 
 
 TW T O further points may be noted in connection with the 
 effect at the site of inoculation. The first of these is for two 
 or three weeks after inoculation a hard nodule, about the size 
 of a large pea, may be felt on rolling the subcutaneous tissue 
 between the finger and thumb. 
 
 The second, and this is a theoretically interesting point, is 
 that it has been reported to me both from India and from 
 South Africa that the site of inoculation has in isolated 
 instances become painful in the case of patients who have 
 contracted typhoid within a few months subsequent to 
 inoculation. 
 
 Constitutional Symptoms. Constitutional symptoms gene- 
 rally supervene on inoculation within the space of two or 
 three hours. Upon one occasion, when experimenting at 
 
 1 Author's paper, British Medical Journal, July 14, 1894.
 
 ANTI-TYPHOID INOCULATION. 41 
 
 Netley on four professional colleagues, I have seen rigors 
 supervene in each case within a quarter of an hour. The 
 vaccine inoculated in these cases consisted of one quarter of a 
 cubic centimeter of a sterilised broth-culture of a typhoid bacillus 
 which had been recently isolated from a patient dead of the 
 disease. 
 
 It is to be noted that the onset of the constitutional 
 symptoms is hastened and the severity of these symptoms is 
 increased where any muscular exercise is engaged in imme- 
 diately after inoculation. 
 
 It has also appeared to me that inoculation undertaken 
 upon a fasting patient is followed much more rapidly by 
 constitutional symptoms and also by symptoms of a severer 
 type. This last observation, be it noted, has a considerable 
 theoretical interest. The reader who is familiar with Ehrlich's 
 theory of immunity and with von Dungern's experiments l in 
 connection with the immunisation of rabbits against the blood 
 of a particular variety of crab will recognise that the occupation 
 with food of the receptors which subserve the nutrition of the 
 cell may quite well delay the incorporation of the toxic elements 
 of the vaccine with the cell-protoplasm. 
 
 With the doses of vaccine which I now employ doses 
 which I have said are quite sufficient to elicit a satisfactory 
 elaboration of typhotropic elements the constitutional symp- 
 toms are limited to some headache, and to two or three hours 
 of real malaise. As soon as these symptoms have passed off 
 generally five to six hours after the inoculation the patient 
 feels inclined for food and for sleep. The sleep which is 
 obtained is of course somewhat broken. Next day his tem- 
 perature comes down to normal, and he feels comparatively 
 well except in the respect of pain at the seat of inoculation. 
 
 With the larger single close which was employed during the 
 South African campaign symptoms of collapse and rigors were 
 not unfrequent. These symptoms, although to the experienced 
 eye they in some cases appeared alarming, in no case led to 
 any accident. 
 
 Recovery appears to have been slow in some cases where 
 severe constitutional symptoms were produced. It may be 
 
 1 V. Dungern: Die Antikorpcr, p. 103, Jena, 1903.
 
 42 ANTI-TYPHOID INOCULATION. 
 
 surmised that such delayed recovery was associated with a 
 prolongation of the negative phase. 
 
 The practical conclusion which is to be drawn from the 
 above is that, where circumstances allow of this being done, it 
 is advisable to employ, instead of the one severe inoculation 
 (which had under the circumstances to be employed in my 
 inoculations in India and in the case of most of the inocula- 
 tions undertaken upon soldiers proceeding to South Africa), 
 two successive inoculations, adjusted so as to avoid the super- 
 vention of severe constitutional symptoms. Experience further 
 shows that the patient may with advantage partake of some 
 light nourishment immediately before or immediately after 
 anti-typhoid inoculation ; and that he should avoid all physical 
 exertion after inoculation. He may in fact with advantage 
 betake himself to bed or in winter to an arm-chair by the 
 fireside as soon as possible after the injection. A dose of 
 calcium chloride may also be administered to him.
 
 ANTI-TYPHOID INOCULATION. 43 
 
 CHAPTER IV. 
 
 ON THE PROTECTIVE EFFECT OF ANTI-TYPHOID 
 INOCULATION AS EXHIBITED IN THE STATISTICAL RECORDS. 
 
 Before addressing ourselves to the study of the statistical 
 records of anti-typhoid inoculation we may with advantage 
 consider certain fundamental points which concern the cogency 
 of statistical evidence. 
 
 i. In every case where an enquiry is to be made as to 
 whether a particular inoculation exerts a protective effect, it is 
 essential that there should be included in the observation along 
 with a group of inoculated men also a control group of unin- 
 oculated men. The control group, which ought to correspond 
 with the inoculated group in all points save only in the circum- 
 stance of inoculation, is required for the purpose of furnishing 
 information as to what, in the absence of inoculation, would 
 have been the incidence and the case-mortality of the particular 
 disease under consideration among those who are included in 
 the inoculated group. 
 
 2. It is further essential that there should be placed upon 
 record the exact numbers of both the inoculated and uninocu- 
 lated groups, and the percentage incidence, and case-mortality 
 of each group. 
 
 FALLACIES AND ERRORS WHICH ARE INCIDENT TO STATIS- 
 TICAL RECORDS SUCH AS THOSE WHICH COME INTO 
 CONSIDERATION IN CONNECTION WITH ANTI-TYPHOID 
 INOCULATION. 
 
 To the reader who has not had to concern himself with 
 furnishing or, as the case may be, with sifting statistical evidence, 
 it will perhaps appear a very simple matter to comply with 
 the elementary statistical canons formulated above. In point 
 of fact experience teaches that the code can never be wholly 
 conformed to. It follows and this ought to be put in the 
 forefront in considering any statistical evidence that the 
 exploitation of statistics without critical discussion furnishes 
 proof either of the naivete of the statistician, or of a desire to
 
 44 ANTITYPHOID INOCULATION. 
 
 turn to advantage that inborn distaste for intellectual effort, 
 which is the most characteristic feature in the psychological 
 organisation of man. 
 
 The more important of the complexities which encumber 
 statistical evidence, such as we have here to deal with, are the 
 following : 
 
 i. It is hardly ever practicable to obtain in an absolutely 
 accurate manner the respective numbers of the inoculated and 
 uninoculated. 
 
 This seemingly paradoxical proposition is justified by the 
 following considerations : 
 
 (a) The number of men in inoculated and uninoculated 
 groups is almost inevitably subject to variation during the course 
 of the period covered by the observation. In the case, for 
 instance, of a regiment in India or on service new drafts arrive 
 to join the regiment, time-expired men and invalids return 
 home, and occasional transfers are made. The statistical 
 difficulty which thus arises can be surmounted only by 
 recording for each inoculated and uninoculated man the number 
 of days in which he has been under observation with the 
 regiment. 
 
 It will be noted on consulting the critical commentary 
 appended to the statistical table given below that this statistical 
 method has superseded in the case of the Indian statistics for 
 the year 1901 the uncritical method of enumeration employed 
 in the two preceding years. 1 
 
 () In the case where inoculations are undertaken in the 
 course of an epidemic, we have to deal with a group of un- 
 inoculated decreasing de die in diem, and with a group of 
 inoculated increasing in the same manner. 
 
 This statistical difficulty, and the difficulty arising from 
 the associated spontaneous rise and fall of the epidemic, can 
 be surmounted only by calculating the incidence upon the 
 average strength of the two groups during the period of 
 observation, and by calculating the risk of infection before and 
 after the date upon which the average strength was reached. 
 The somewhat intricate principles of this method of computa- 
 tion will be found fully discussed in the chapter of the Indian 
 
 1 The introduction of this more critical method of enumeration is due to the 
 inspiration of Major T. MacCullagh, R.A.M.C.. the present statistical officer at 
 the head-quarters of the Army Medical Department.
 
 ANTI-TYPHOID INOCULATION. 45 
 
 Plague Commission (Chapter IV., para. 434) which deals with 
 the statistical results of Haffkine's anti-plague inoculations. 
 The method finds exemplification in a paper l in which I have 
 set forth the results obtained by anti-typhoid inoculation in the 
 case of an epidemic of typhoid fever which took place in the 
 Richmond Asylum, Dublin. 
 
 (c) In the case where subsequent to inoculation, but within 
 the limits of the incubation-period, cases of the disease occur a 
 difficulty arises as to how these cases are to be brought upon 
 the record. 
 
 It is traditionary with the medical statistician to exclude 
 all such cases from consideration. I think this practice is to 
 be deprecated first, because it can never be certain in the 
 case of an inoculated man that his susceptibility to the disease 
 has not been temporarily increased by inoculation ; secondly, 
 because it is important to have set forth the balance of advan- 
 tage and disadvantage of inoculation undertaken in the actual 
 presence of infection. 
 
 2. // is a matter of great difficulty to secure the exact com- 
 parability of the inoculated and uninoculated groups. 
 
 It was laid down above as one of the theoretical requisites 
 in connection with statistics that the control group should 
 correspond with the inoculated group in all points save only 
 with respect to inoculation. We are compelled in actual practice 
 to abate something from this theoretical requisite. But it is 
 in all cases essential that the control group shall consist of 
 persons who are similar to the inoculated with respect to age, 
 and of persons who live under similar conditions, and who are 
 exposed for the same period to the similar risks of infection. 
 
 When these essential points have been neglected the statis- 
 tical conclusions arrived at are entirely without coercive force. 
 
 Illustration of the vitiation of statistical records by omission 
 to consider the question of the comparability of the inoculated 
 and uninoculated groups is furnished by the statistical record 
 Xo. 22 in the synoptical table, pp. 54 and 55. 
 
 The next-following statistical record furnishes illustration ot 
 the fact that a statistical conclusion arrived at by a comparison 
 of the inoculated with a control group selected at random may 
 
 1 Brit. Meet. Jonrn., October 26, 1901.
 
 46 ANTI-TYPHOID INOCULATION. 
 
 be the exact reverse of the conclusion which emerges from a 
 comparison with a properly selected control group. 
 
 3. // has not always been possible to secure a correct assig- 
 nation of the sick to the inoculated and nninoculated groups 
 respectively. 
 
 The determination of the point as to whether a particular 
 patient belongs to the group of the inoculated or uninoculated 
 would also at first sight appear to be an absolutely simple 
 operation in which it would be impossible to go wrong. This 
 may be taken to be so in the case of soldiers where the fact of 
 inoculation has been entered upon the Medical History Sheets, 
 and where, as in time of peace, the Medical History Sheets are 
 available. Quite other were the conditions in the case of the 
 men entered as inoculated or uninoculated respectively on the 
 records of many of the Military Hospitals in South Africa. The 
 classification of the patient as inoculated or uninoculated 
 depended here upon his own statement. A serious source of 
 error was thus introduced. In certain cases where the soldier 
 desired to avoid inoculation, and suspected that this would 
 follow if he returned himself as uninoculated, a strong motive 
 existed for making a false return. In other cases, again, 
 confusion arose in the man's mind between anti-typhoid 
 inoculation and anti-smallpox vaccination, the confusion being 
 due to the fact that both these procedures were undertaken on 
 the transports on passage to South Africa. 
 
 In addition to these sources of misclassification there were 
 many others which are best passed over in silence. 
 
 4. In a considerable percentage of cases it is notoriously a 
 matter of difficulty to arrive at a certainty in the differential 
 diagnosis of typhoid fever. 
 
 The difficulty of the differential diagnosis of typhoid fever 
 from other levers is notorious. In the case of the army, and 
 in particular in the case of the army on field service, there 
 exists a very intelligible bias in favour of arriving at definite 
 diagnoses ; and the diagnosis which is most in favour in the 
 case of fevers is the diagnosis of typhoid fever. 
 
 It follows that, even putting other difficulties aside, the 
 difficulties associated with diagnosis would make absolute 
 accuracy unattainable in statistics referring to the effect of anti- 
 typhoid inoculation.
 
 ANTI-TYPHOID INOCULATION. 47 
 
 The effect of the inclusion of these doubtful cases, or, as 
 we may perhaps conveniently call them, pseudo-typhoid cases, 
 in the statistical records will, as consideration will show, 
 operate to the prejudice of reputation of anti-typhoid inocu- 
 lation. It will operate in this manner, inasmuch as the 
 protection will be judged to have failed, not only when the 
 patient contracts typhoid fever, but also when he contracts 
 any kind of which is confused with typhoid fever. 
 
 5. // is difficult to ensure accuracy in the recording of the 
 facts. 
 
 Up to the present we have had under consideration errors 
 which partake of the nature of fallacies as distinguished from 
 errors arising from sheer inaccuracy and inadvertence. These 
 last, however, can never be completely avoided, and it behoves 
 the statistician in all cases to make careful enquiry for them. 
 On consulting the critical commentary appended to the 
 statistical table below, it will be seen that more or less serious 
 
 inaccuracies have been detected in connection with four or five 
 
 / 
 
 of the statistical records. 
 
 QUESTION AS TO WHAT STATISTICAL EVIDENCE MAY BE 
 ACCEPTED AS COERCIVE. 
 
 In view of the fact that flaws will reveal themselves, if 
 only they are diligently and conscientiously sought for, in all 
 statistical evidence, the question urgently presents itself as to 
 when and under what circumstances the evidence of imperfect 
 statistics as the protective effect of an inoculation may be 
 accepted as coercive. 
 
 The reply that will be made to this question by persons 
 gifted with very great critical acumen will be that it never 
 becomes coercive. Persons who desire to wait till the evidence 
 is obtained which satisfies the theoretical canons set forth at 
 the outset of this statistical discussion are persons who desire 
 to wait indefinitely. The plain, everyday man will find it 
 possible to reconcile the demands of his statistical conscience 
 with the demands of practical life. He will neglect the mint 
 and anise and cummin of statistical criticism while holding fast 
 to weightier principles of the statistical law.
 
 48 ANTI-TYPHOID INOCULATION. 
 
 The essential principles of this law may be compressed into 
 the following propositions : 
 
 i. Where a flaw has been detected in a statistical record the 
 effect of that flaw upon the cogency of the statistical conclusion 
 is to be evaluated. The statistical conclusion in question is to 
 be upheld where the error is shown to be one which is incapable 
 of exerting an appreciable influence on the result. 
 
 Example i. In the case of the "statistics relating to the 
 effect of anti-typhoid inoculation in the garrison of India for 
 the year 1900 (Synoptical Table, serial number 6), there is 
 a confessed error in the enumeration of the inoculated. That 
 error may, it is estimated, amount to " some hundreds." The 
 proper way to deal with this situation is, not to set aside the 
 statistics, but to consider instead what would be the maximum 
 effect which an error of this particular magnitude is capable 
 of exerting upon the statistical conclusion. Interpreting the 
 error of " some hundreds " in the enumeration of the inocu- 
 lated in a liberal spirit as an error of 600 one way or the other, 
 the error in the enumeration of the group would amount to 
 a lo-per-cent. error. This particular statistical conclusion is 
 thus seen to be subject to a lo-per-cent. error. In relation 
 to the broad issues which are here under discussion such an 
 error is insignificant. It is a matter of quite subordinate 
 interest whether the diminution of mortality in the inoculated 
 was the 4* 4-fold diminution which is actually registered, or 
 a 4 -8-fold, or only a 4-fold diminution. 
 
 Example 2. An even more striking illustration of the 
 importance of working in accordance with this statistical 
 principle is afforded by the statistics relating to the garrison of 
 Egypt for 1900 (Synoptical Table, serial number 5). Here 
 we have recorded an 1 8-fold diminution in the incidence of 
 typhoid fever among the inoculated, numbering 700 odd, as 
 compared with the uninoculated taken as some 2,600 odd. 
 If we include in the number of the inoculated those inoculated 
 in the previous year, who are specifically excluded from the 
 statistical returns here in question, we arrive at an inoculated 
 strength of over 1,000 and obtain a 25-fold diminished 
 incidence. If, again, waiving the legitimacy of this course, 
 we include among the uninoculated the full number of troops
 
 ANTI-TYPHOID INOCULATION. 49 
 
 who passed through Egypt in the course of the year in con- 
 nection with military movements to South Africa, we bring 
 up our uninoculated strength to some 5,000 and obtain only 
 a 13 '5-fold diminution. For settling the broad issue which 
 we h?ve in view in this paper it matters nothing whether we 
 accept the highest or the lowest of the above figures as 
 representing the diminution in typhoid incidence achieved in 
 the inoculated. 
 
 2. Where a flaw has been detected in a statistical record 
 and where it has been show?i that the error in question is an 
 error of such magnitude as to be capable of reversing the 
 statistical conclusion arrived at, the statistical record in question 
 is to be rejected, except in the case where data are accessible 
 which allow of the correction of the error. 
 
 Examples. Examples of statistical flaws which invalidate 
 the conclusion arrived at are furnished by Dr. Melville's 
 statistics and Dr. Crombie's first statistics (Synoptical Table, 
 serial numbers 7 and 22 respectively). Dr. Crombie's second 
 statistics, as embodied in the Synoptical Table below (serial 
 number 23), furnish an example of a statistical record which 
 may be accepted after it has been corrected in the manner 
 provided for by its author. 
 
 3. Where the figures are large, all chance errors which 
 may have been committed in the enumeration of the inoculated 
 and uninoculated or in the classification of the sick are spon- 
 taneously eliminated, and the statistical conclusions which 
 emerge may so far be accepted with confidence. 
 
 When the figures are small the statistical conclusion is 
 uncertain even in the case where the facts have been accurately 
 recorded. 
 
 Examples. The figures (Synoptical Table, serial numbers 2, 
 6, and 25) for the inoculated and uninoculated in the garrison 
 of India for each of the three successive years 1899, 1900, 
 and 1901 are sufficiently large to eliminate the operation of 
 chance. 
 
 The figures (Synoptical Table, serial number 13) for the 
 case-mortality of the inoculated and uninoculated collected by 
 Dr. Dodgson from various Military Hospitals in South Africa 
 are sufficiently large to eliminate the operation of chance. 
 
 The figures for the case-mortality of the inoculated and
 
 50 ANTI-TYPHOID INOCULATION. 
 
 uninoculated obtained by Drs. Elliot and Washbourn (Synop- 
 tical Table, serial number 12) are too small to insure the 
 elimination of the operation of chance. 
 
 4. Where there is a source of error which runs through all 
 the statistics and operates always in one and the same direction, 
 that error is not eliminated by the cumulation of figures. 
 
 Example. The error which is introduced into the statistical 
 records by the inclusion of pseudo-typhoid cases among the 
 typhoid cases is not eliminated by the accumulation of figures. 
 
 It will be remembered that this is an error which operates 
 to the prejudice of the reputation of anti-typhoid inoculation. 
 
 SYNOPTICAL TABLE OF ALL THE STATISTICAL RECORDS 
 RELATING TO ANTI-TYPHOID INOCULATION. 
 
 The Synoptical Table below consists essentially of a reprint 
 of the table which I embodied in my statistical paper published 
 in the Lancet of Sept. 6th, 1902. I have brought it up to date 
 by adding to it three further statistical records which have 
 become available since the publication of my former paper. As 
 explained in connection with my former publication, I have in 
 my table in each case set out the statistical materials in the 
 form in which those materials were furnished by their authors, 
 except only in the respect that I have incorporated with them, 
 whenever such were available, data with regard to the dates of 
 the observations and certain other points of interest. 
 
 To the Synoptical Table I have appended a critical com- 
 mentary. In this I have set forth, but somewhat less fully, 
 the facts which were furnished in Table II. of my previous 
 paper. I desire to emphasise that the data given in the 
 Synoptical Table ought to be studied in the light of the critical 
 commentary.
 
 ANTI-TYPHOID INOCULATION. 51 
 
 I. STATISTICS OF ANTI-TYPHOID INOCULATION.
 
 5 2 
 
 ANTI-TYPHOID INOCULATION. 
 
 I. STATISTICS OF ANTI- 
 To be studied in Connection with the 
 
 1 
 
 g 
 
 Group 
 . which was under 
 
 Interval 
 between 
 Inocula- 
 tion and 
 Com- 
 
 Place 
 where 
 Group 
 
 Period of 
 Observation 
 covered 
 
 Authority 
 for the 
 
 Reference 
 to published 
 Literature 
 
 Number of in- 
 oculated and 
 uninoculated 
 in the Group. 
 
 *o 
 
 3 
 
 Obsnvation. 
 
 mence- was ex- 
 
 by the 
 
 Statistics. or other Source 
 
 V 
 
 Sm' 
 
 "rt 
 
 
 Period of P ose " * 
 
 Statistics. 
 
 of Information. 
 
 "3 
 
 o ~ 
 
 .5 S 
 
 I 
 
 V) 
 
 
 Exposure. Infection. 
 
 
 
 
 g 
 a 
 
 D 
 
 I 
 
 Nurses and Attend- No Barming Oct. to end Dr. J. S. Tew. 
 
 Public Hea'th, 84 
 
 116 
 
 
 ants, Barming interval. 
 
 Asylum, of epidemic. 
 
 Mr. A. G. R. 
 
 Mar , 1898. 
 
 
 
 Asylum. 
 
 
 Maid- 
 
 1897. 
 
 Foulerton. The Lancet, 
 
 
 
 
 
 stone. 
 
 
 Dr. A. M. 
 
 June 2, 1900. 
 
 
 
 
 
 
 
 Jackson. 
 
 
 
 2 
 
 Inocul 'ted Regi- No Various 
 
 1899 
 
 Official 
 
 Army Medical 4,502 25,851 
 
 
 ments and other interval. Stations 
 
 returns. 
 
 Report for 1899. 
 
 
 Units of the in India. 
 
 
 
 
 
 British Army in 
 
 
 
 
 
 
 
 India. 
 
 
 
 
 3 
 
 I5th Hus'ars, wives Probably Meerut, Oct , 1899, 
 of fa'ne, and a few India. to 
 
 Official 
 returns. 
 
 Brit. Med. Jour. 360 179 
 and The Lancet, 
 
 
 officers. weeks. 
 
 Oct., 1900. 
 
 
 Feb. g, 1901 ; 
 
 
 
 
 
 
 reported by Prof. 
 
 
 
 
 A. E. Wright. 
 
 4 
 
 Garrison of Two Lady- Nov. 2, 1899, 
 Ladysmith. months smith, to Fel>. 28, 
 
 Official 
 returns. 
 
 Brit. Med. Jour. 1,705 10,529 
 and The Lancet, 
 
 
 to ii South 
 
 1900. 
 
 
 July 14, 1900; 
 
 
 
 
 
 months. Africa. 
 
 
 
 reported by Prof. 
 
 
 
 
 
 
 Wright. 
 
 5 
 
 British Garrison No Egypt and 1900 
 
 Report of 
 
 Brit. Wed. Jour. 720 2,669 
 
 
 of Egypt and interval. 
 
 Cyprus. 
 
 
 Principal 
 
 and The Lancet, 
 
 
 Cyprus. 
 
 
 
 Medical 
 
 May 4, 1901 ; 
 
 
 
 
 
 
 Officer, 
 
 reported by Prof. 
 
 
 
 
 
 
 
 Egypt. 
 
 Wright. 
 
 6 
 
 British Garrison Varying 
 
 India. 
 
 1900 
 
 Official 
 
 A rmy Medical 5,999 54.554 
 
 
 in India. from no 
 
 
 returns. 
 
 Report for 
 
 
 interval 
 
 
 
 
 1900. 
 
 
 
 to one 
 
 
 
 
 
 
 year. 
 
 
 
 
 
 7 
 
 Patients in Tin- No data. South Dr. D. Brit. Med. J^ur., 
 
 
 
 
 town Hospital, Africa. | Melville. Vol. I., 1901. 
 
 
 Ladysmith. 
 
 
 
 8 
 
 Patients in S">uth 
 
 Sept.. 1900. 
 
 Maj. C. Birt, Brit. Mel. Jour., 
 
 
 Stationary Hos- 
 
 Africa. 
 
 to 
 
 R.A.M.C. Jan. ii, 1902. 
 
 
 
 pital, Harrismith. 
 
 
 
 Sept., 1901. 
 
 
 
 
 
 9 
 
 Patients in Port- 
 
 
 South 
 
 1900. 
 
 Dr. H. H. 
 
 Brit. Med. Jour., 
 
 
 
 
 land Hospital. 
 
 Africa. 
 
 Tooth. Mar. 16, 1901. 
 
 
 
 10 
 
 Patients in the 
 
 South 1900. 
 
 Dr. J B. Transactions of the 
 
 
 
 
 
 Irish 
 
 Africa. 
 
 
 Coleman. Royal Academy of 
 
 
 
 
 Hospital. 
 
 
 
 
 Medicine in Ireland, 
 
 
 
 
 
 
 
 Vol. XIX. 
 
 
 
 ii Patients in Scottish South 
 
 19 o 
 
 Colonel Brit. Med. Tnur., 
 
 _ 
 
 National Red Africa'. 
 
 
 Henry Jan. 12, 1901. 
 
 
 
 Cross Hospital. 
 
 
 
 
 Cayley, 
 
 
 
 
 
 
 I M.S. 
 

 
 ANTI-TYPHOID INOCULATION. 
 
 53 
 
 TYPHOID INOCULATION. 
 Critical Commentary appended. 
 
 Number of 
 Cases of 
 Typhoid 
 Fever. 
 
 Percentage 
 Incidence 
 of the 
 Disease. 
 
 Number of 
 Deaths from 
 Typhoid 
 Fever. 
 
 Percentage 
 Death-rate 
 for Typhoid 
 Fever. 
 
 Case Mortality 
 i.e., Proportion of 
 Deaths to Cases. 
 
 Supplementary Facts. 
 
 Ill 
 
 jli 
 
 s~~ 
 
 uninocu- 
 lated. 
 
 j| 
 
 iminocu- 
 lated. 
 
 3 . 
 OT3 
 
 11 
 
 (fl 
 
 nninocu- 
 lated. 
 
 II 
 
 jninocu- 
 
 late.l. 
 
 h 
 
 Inuninocu- 
 lated. 
 
 J3 
 
 
 c 
 
 9 
 
 a 
 
 
 JB 
 
 
 
 
 4 
 
 
 
 3'4 
 
 
 
 
 
 
 
 
 
 
 
 
 
 12 cases of typhoid fever had occurred 
 in the staff, numbering about 200, 
 before the inoculations were under- 
 taken. 
 
 44 
 
 657 
 
 0-98 
 
 . 
 
 9 
 
 146 
 
 0'2 
 
 ..* 
 
 i in 4-9 
 
 i in 4-5 
 
 
 
 2 
 
 II 
 
 o'55 
 
 6-14 
 
 i 
 
 6 
 
 0-27 
 
 3'35 
 
 i in 2 
 
 i in 2'2 
 
 
 
 35 
 
 1,489 
 
 2 '05 
 
 14-14 
 
 8 
 
 329 
 
 .. 
 
 3'12 
 
 i in 4-7 
 
 i in 4-5 
 
 
 
 i 
 
 68 
 
 0-14 
 
 2'55 
 
 I 
 
 10 
 
 0-I 4 
 
 '37 
 
 i in i 
 
 i in 6-8 
 
 
 
 52 
 
 
 
 
 
 i '69 
 
 8 
 
 224 
 
 0-13 
 
 0-58 
 
 i In 6-5 
 
 i in 3-3 
 
 
 
 30 
 
 265 
 
 - 
 
 - 
 
 2 
 
 5 
 
 - 
 
 - 
 
 i in 15 
 
 i in 53 
 
 
 
 263 
 
 947 
 
 
 
 18 
 
 135 
 
 
 
 rinu'6 
 
 i in 7 
 
 A comparison of 151 charts refeni 3g 
 to inoculated patients will 317 
 charts referring to uninoculated 
 patients showed that the height of 
 the fever, the duration of the same, 
 the percentage of relapses, and the 
 number of daily evacuations were 
 much less in the inoculated. 
 
 54 
 
 178 
 
 - 
 
 - 
 
 4 
 
 25 
 
 - 
 
 - 
 
 i in 13-5 
 
 i in 7 
 
 
 80 
 
 592 
 
 - 
 
 - 
 
 5 
 
 74 
 
 - 
 
 - 
 
 i in 16 
 
 i in 8 
 
 
 
 15 
 
 70 
 
 - 
 
 - 
 
 i 
 
 10 
 
 - 
 
 - 
 
 i in 15 
 
 i in 7 
 
 
 
 E 2
 
 54 
 
 ANTI-TYPHOID INOCULATION. 
 
 
 
 
 Number of in- 
 
 1 
 
 between 
 Group Inocula- 
 tion and 
 which was under Com- 
 
 Place 
 where 
 Group 
 
 Period of 
 Observation 
 covered 
 
 Reference 
 Authority to published 
 
 for the Literature 
 
 oculated and 
 uninoculated 
 in the Group 
 
 T-l 
 
 
 a 
 
 mence- ' was ex- ; , f , 
 Observation. ment of 
 Period of P sedt Statistics. 
 
 Statistics. or other Souroe 
 of Information. 
 
 . 
 
 11 
 
 n 
 
 ^ Exposure. Infection. 
 
 
 B 
 
 
 c_a 
 
 1 
 
 ' ! I 
 
 
 c 
 
 3 
 
 12 
 
 Patients in 
 
 No data. South 1900-1901 
 
 Dr A Elliot The Lancet, 
 
 _ 
 
 _ 
 
 
 Imperial Yeomanry 
 
 Africa. 
 
 and Dr. J. W. 
 
 Jan. 18, 1902. 
 
 
 
 
 Hospitals. 
 
 
 
 Washbuum. 
 
 
 
 
 13 
 
 Patients in a 
 
 
 South 
 
 1900-1901 
 
 Dr. R. W. 
 
 Official report. 
 
 
 
 
 Variety ot Military 
 
 
 Africa. 
 
 
 Dodgson. 
 
 
 
 . 
 
 Hospitals. 
 
 1 
 
 
 - 
 
 
 
 14 Staff of the Port- A few i South Part ot 
 
 Dr. Tooth. 
 
 Brit. Med. Jour., 28 13 
 
 land Hospital. weeks. * Africa. 1900. 
 
 
 Mar. 16, 1901. 
 
 
 15 Staff of Imperial No data. 
 
 South 
 
 No data. 
 
 Dr. Elliot 
 
 The Lancet, 59 
 
 25 
 
 Yeomanry Hospital, , 
 
 Africa. 
 
 
 and Dr. 
 
 Jan. 18, 1902. 
 
 
 
 Deelfontein. 
 
 
 
 
 Washbourn. 
 
 
 
 (6 
 
 Stafl of Imperial In most 
 
 South 
 
 Aug., 1900, 
 
 Dr. Dodgson. Official report. 32 
 
 72 
 
 
 Yeomanry Hospital, cases 
 
 Africa. 
 
 10 
 
 
 
 
 
 Pretoria. 
 
 a few 
 
 
 Mar., 1901. 
 
 
 
 
 
 
 
 weeks. 
 
 
 
 
 
 
 17 
 
 No ' 8 ) General 
 No. 9 > Hospitals 
 
 A few Blqem- 
 weeks. fontein, 
 
 Qrsnfli 
 
 April to 
 Aug., 1900. 
 
 i : 
 
 " 
 
 87^108 47 > 276 
 
 
 No.io)< staffsof) - 
 
 OOUIU 
 
 Africa. 
 
 
 1 ,. 
 
 
 
 o) 119) 
 
 c8 
 
 Staff of Second 
 
 A few South 
 
 Part of 
 
 Colonel 
 
 Brit. Mel. Jour., 
 
 70 
 
 12 
 
 | 
 
 Section, Scottish 
 Red Cross Hospital. 
 
 weeks. Africa. 
 
 1900, 
 
 Cayley, 
 
 I.M.S. 
 
 Jan. 12, 1901. 
 
 
 
 '9 
 
 Fifth Battalion, 
 
 A few 
 
 Winburg, 
 
 July. 1901, 
 
 Lieutenant 
 
 Brit. Med. Jour. 
 
 200 
 
 517 
 
 
 Manchester 
 
 weeks. 
 
 South " to 
 
 J. W. West, and The Lancet, 
 
 
 
 
 Regiment. 
 
 
 Afric i. 
 
 Feb., 1902. 
 
 RA.M.C. April 5, 1902, 
 
 
 
 
 
 
 
 
 reported by 
 
 
 
 
 
 
 
 
 
 Prof. Wright 
 
 
 
 20 
 
 City Imperial 
 
 Probibly 
 
 South 
 
 1900 
 
 Surgeon- Privately 
 
 700 
 
 494 
 
 
 Volunteers. 
 
 a tew Africa. 
 
 
 Major R R. communicated. 
 
 
 
 j 
 
 
 weeks. 
 
 
 
 Sleinan, 
 
 
 
 
 
 
 
 
 C.I.V. 
 
 
 
 
 21 
 
 Patients in Rich- 
 
 No Dublin. 
 
 Sept., 1900, 
 
 Mr. H. M. Brit. Med.Jnur., 
 
 3'9 
 
 298 
 
 
 mond Asvlum, interval. 1 to 
 
 C oil man. Oct. 26, 1901 ; 
 
 
 
 
 Dublin. 
 
 
 
 Dec., 1900. 
 
 reported by 
 
 
 
 
 
 
 
 
 Prof. Wright. 
 
 
 
 22 
 
 Officers invalided 
 
 A few 
 
 South 
 
 No data. 
 
 Colonel A. 
 
 The Larcct, 
 
 112 
 
 109 
 
 
 from South Africa 
 
 weeks. 
 
 Africa. 
 
 
 Crombie, May 3, 1902 
 
 
 
 
 (first series). 
 
 
 
 
 I.M.S. 
 
 
 
 23 
 
 Officers invalided 
 
 In most 
 
 Sou'.h 
 
 No data. 
 
 Colonel A. The Lancet, 
 
 102 
 
 85 
 
 
 from South Africa 
 
 cases 
 
 Africa. 
 
 
 Crombie, Aug 16, 1902. 
 
 
 (second series). 
 
 only a 
 
 
 
 I.M.S. 
 
 
 
 few 
 
 
 
 
 
 
 
 weeks. 
 
 
 
 
 

 
 ANTI-TYPHOID INOCULATION. 
 
 55 
 
 
 Num 
 Cas< 
 Typ 
 Fe 
 
 || 
 c~~ 
 
 berof 
 :s of 
 bold 
 ver. 
 
 Percentage 
 Incidence 
 of the. 
 Disease. 
 
 Number of 
 Deaths from 
 Typhoid 
 Fever. 
 
 Percentage 
 Death-rate 
 for Typhoid 
 Fever. 
 
 Cae Mortality 
 i.e.. Proportion of 
 Deaths to Cases. 
 
 Supplementary Facts. 
 
 In uninocn- 
 lated. 
 
 In inocu- 
 lated. 
 
 In unlnocu- 
 lated. 
 
 In inocu- 
 lated. 
 
 In uninocu- 
 lated. 
 
 In inocu- 
 lated. 
 
 In uninocu 
 lated. 
 
 In inocu- 
 lated. 
 
 In uninocu- 
 lated. 
 
 47 
 
 301 
 
 - 
 
 - 
 
 4 
 
 26 
 
 - 
 
 - 
 
 i in n'g 
 
 i In n'8 
 
 
 
 
 764 
 
 3,374 
 
 - 
 
 - 
 
 63 
 
 5io 
 
 - 
 
 - 
 
 i in 12 
 
 i in 6-6 
 
 
 
 
 7 
 
 3 
 
 25 
 
 23 
 
 . 
 
 i 
 
 
 
 7 
 
 oin 7 
 
 i in 3 
 
 Five of the inoculated had very light 
 attacks. 
 
 
 
 4 
 
 A 
 
 6-8 
 
 16 
 
 
 
 o 
 
 - 
 
 - 
 
 oin4 
 o in 3 
 
 o in 4 
 o in 7 
 
 
 
 
 
 
 
 
 
 
 5 !- 6 
 it > 
 
 _ 
 
 "I 
 13 >93 
 
 36 J 
 
 (14-8 
 
 j 
 
 ;i- 
 
 'I 
 
 2>l6 
 
 6J 
 
 jo'9 
 
 !- 
 
 | i in 16 
 
 >i ins'8 
 
 The period of observation covers the 
 period of " the great epidemic." 
 
 
 2 
 
 4 
 
 2'8 
 
 33'3 
 
 i 
 
 I 
 
 1*4 
 
 8-3 
 
 I 2 
 
 i in 4 
 
 There was no enteric in the first section, 
 which consisted of 77 doubly inocu- 
 lated and two uninoculated persons. 
 The third section, which consisted 
 of 20 inoculated persons, also re- 
 mained free. 
 
 
 3 
 
 23 
 
 I'S 
 
 4'2 
 
 
 
 j 
 
 
 
 i'3 
 
 oin 3 
 
 i in 3-3 
 
 The three inoculated had very mild 
 attacks. Some of the inoculated 
 were not yet out of danger at the 
 date of rendering the report. 
 
 
 60 
 
 39 
 
 8-5 
 
 7'9 
 
 9 
 
 II 
 
 i'3 
 
 2*2 
 
 in6'7 
 
 i in 3-5 
 
 
 
 
 6 
 
 30 
 
 1-8 
 
 I0'0 
 
 i 
 
 4 
 
 o'3 
 
 t-3 
 
 i in 
 
 i in 7-5 
 
 The period of observation closed with 
 the end of the epidemic. 
 
 
 3 24 28-5 
 
 22*0 
 
 - 
 
 - 
 
 - 
 
 - 
 
 - - 
 
 
 34 
 
 28 
 
 33 - 3 
 
 32-9 
 
 
 
 
 
 
 
 
 
 
 
 The proportion of typhoid con- 
 valescents among the inoculated 
 under 26 years of age was i in 3 ; 
 among the uninoculated, 2 in 3 ; 
 among 13 twice inoculated, i in 1*3 ; 
 among 89 once inoculated, i in 3*7.
 
 ANTITYPHOID INOCULATION. 
 
 Serial Number. 
 
 Group 
 which was under 
 Observation. 
 
 Interval 
 between 
 Inocula- 
 tion and 
 Com- 
 mence- 
 ment of 
 Period of 
 Exposure. 
 
 Place 
 where 
 Group 
 was ex- 
 posed to 
 Infection. 
 
 Period of 
 Observation 
 covered 
 by the 
 Statistics. 
 
 Authority 
 for the 
 Statistics. 
 
 to published 
 Literature 
 or other Source 
 of Information. 
 
 Number of in- 
 oculated anH 
 uninoculated 
 in the Group. 
 
 "3 
 
 O 
 
 c 
 
 Uninocu- 
 lated. 
 
 24 
 
 7th Hussars, South 
 Africa. 
 
 A few 
 weeks. 
 
 South 
 Africa. 
 
 Dec. 20, 
 1901, to 
 June 20, 
 1902. 
 
 Captain 
 W. A. Ward, 
 R.A.M.C. 
 
 Official report. 
 
 307 
 
 244 
 
 \ 
 
 25 
 
 British Army In 
 India, 1901. 
 
 1-2 years. 
 
 India. 
 
 Jan. to 
 Dec., 1901. 
 
 Official 
 returns. 
 
 Prit. Med. Jour., 
 Oct. 10, 1903. 
 
 '4-883 
 
 55-955 
 
 26 
 
 Lord Methuen's 
 Column, 
 M odder River. 
 
 No data. 
 
 South 
 Africa. 
 
 Dec., 1899, 
 to 
 Mar., 1900. 
 
 Surg.-Gen. 
 Townsend, 
 C.B. 
 
 Ibid. 
 
 2-535 
 
 10,981 
 
 27 
 
 No. 7, General 
 Hospital, Natal. 
 
 Under 
 i year. 
 
 Estcourt, 
 
 Natal. 
 
 April to 
 Aug. 1900. 
 
 Dr. Watkins- 
 Pltchford. 
 
 Paper read before 
 South African 
 Medical Association 
 
 " 
 
 
 CRITICAL COMMENTARY ON THE STATISTICAL RECORDS 
 INCLUDED IN THE SYNOPTICAL TABLE ABOVE. 
 
 The data 1 which are available for the evaluation of the 
 statistical records included in the synoptical table above are 
 set forth below under the following headings : 
 
 A. The system of enumeration adopted ; 
 
 B. The comparability of the inoculated and uninoculated 
 
 groups ; 
 
 c. The trustworthiness of the diagnosis of typhoid fever 
 arrived at ; 
 
 D. The trustworthiness of the classification of the sick as 
 
 inoculated and uninoculated respectively ; 
 
 E. The question as to how far the recorded case-mortality 
 
 correctly represents the case-mortality of the inocu- 
 lated and uninoculated respectively. 
 
 F. The question as to how far the incidence and death-rate 
 
 is affected b}*- the inclusion, among the inoculated, 
 of cases infected before protection was established ; 
 
 G. The light thrown on the question of the duration of 
 
 protection afforded ; and 
 H. The general accuracy of the record. 
 
 1 These data are set forth more fully in Table II., appended to my former 
 apr in the Lancet.
 
 ANTI-TYPHOID INOCULATION. 
 
 57 
 
 Number of 
 Cases of 
 Typhoid 
 Fever. 
 
 Percentage 
 Incidence 
 of the 
 Disease. 
 
 Number of 
 Deaths from 
 Typhoid 
 Fever. 
 
 Percentage 
 Death-rate 
 for Typhoid 
 Fever. 
 
 Case Mortality 
 i.e., Proportion of 
 Deaths to Cases. 
 
 
 
 a 
 
 3 
 
 
 3 
 
 g 
 
 3 
 
 o 
 
 s . 
 
 3 
 
 
 
 o 
 
 Supplementary Facts. 
 
 
 it ii 
 
 || 
 
 o . 
 
 
 11 
 
 11 
 
 CT3 OT3 
 V C 
 
 Ii 
 
 
 
 
 3 
 
 C 
 
 J2 
 
 "c^S 
 
 
 
 
 ga 
 
 a 3 
 
 3 
 
 
 
 - 
 
 a 
 
 
 a 
 
 * 
 
 s 
 
 S 
 
 
 
 " 
 
 5 
 
 
 
 9 20 
 
 2*9 
 
 8'2 
 
 
 
 3 
 
 
 
 1*2 
 
 o in 9 
 
 i In 6-7 
 
 The incidence in 73 once inoculated 
 
 
 
 
 
 
 
 
 
 
 
 was 4* i per cent.; in 231 twice in- 
 
 
 
 
 
 
 
 
 
 
 
 oculated 2*3 per cent. 
 
 
 32 
 
 744 
 
 0-66 
 
 i '33 
 
 3 
 
 199 
 
 0*06 
 
 0-36 
 
 - 
 
 - 
 
 
 
 
 t6 
 
 *57 
 
 1*0 
 
 n 
 
 - 
 
 - 
 
 - 
 
 - 
 
 - 
 
 - 
 
 
 
 
 127 
 
 1.017 
 
 - 
 
 - 
 
 3 
 
 58 
 
 - 
 
 - 
 
 i in 46 
 
 i in 12 
 
 Percentage of mild cases 46 in in- 
 oculated, 23*99 m uninoculated : 
 
 
 
 
 
 
 
 
 
 
 
 
 severe cases in inoculated 19*7 per 
 cent., in uninoculated 21 -92. 
 
 No. i. A. Nominal rolls were made of the inoculated. 
 The number of uninoculated was calculated by subtraction of 
 the inoculated from the total staff. B. There was no difference 
 between inoculated and uninoculated in respect of age or 
 period of exposure to infection ; but the inoculated were in the 
 course of their duties (nursing, laundry work) more exposed 
 to risk than the others. Hence the circumstances in this case 
 were more favourable to the uninoculated. C. The diagnosis 
 was made by the medical officers of the asylum in the midst 
 of a severe epidemic of typhoid, so that the risk of errors is 
 very small. D. There was no chance of either inoculated or 
 uninoculated patients being included in the wrong group. 
 G. An agglutinating reaction was obtained two years afterwards 
 in four out of nine inoculated cases. 
 
 No. 2. A. Nominal rolls were made of the inoculated, and 
 the uninoculated were calculated by subtraction of these from 
 the average yearly strength of the unit. Some inaccuracy thus 
 results, which may tell in favour of either group. B. The 
 inoculated would on the average be younger than the unin- 
 cculated, as special efforts were made to inoculate the younger 
 men. Otherwise the conditions were the same. C. The 
 diagnosis was made by the Army Medical Officers. The 
 existence of malaria and other tropical fevers would introduce
 
 58 ANTI-TYPHOID INOCULATION. 
 
 some risk of error. Such errors would affect both groups 
 equally. D. Records of inoculations were entered on the 
 Medical History-Sheets, and it is possible some errors may 
 have crept in, in either direction, but these would hardly 
 affect the general result. E. Some very slight attacks of 
 typhoid may have passed unrecognised. The facts recorded 
 under the next heading (F) must also be taken into considera- 
 tion, as the case-mortality may be unfavourably influenced 
 when patients are inoculated in the incubation-period of the 
 disease. F. Five cases (two fatal) occurred among the inocu- 
 lated at Lucknow within nineteen days after inoculation ; and 
 one case at Agra within eight days after inoculation. By 
 the occurrence of these cases the incidence-rate among the 
 inoculated was increased from 0*84 per cent, to 0-98, and the 
 death-rate from 0*15 to O'2. 
 
 No. 3. A. As in the last case. B. E. The remarks made 
 in connection with No. 2 apply here. 
 
 No. 4. A. The method of enumeration is not on record. 
 B. The conditions of the two groups may be assumed to be 
 identical, as the inoculated and uninoculated are included in 
 many different military units, c. The diagnosis was made by 
 Army Medical Officers and Civil Surgeons, working under the 
 strain of war in a beleagured town. D. As to the classification, 
 see under No. 13, p. 60. H. Of two deaths recorded to have 
 occurred among inoculated officers, one was due to a casualty 
 in the field. The other officer had been inoculated with a 
 serum, not with anti-typhoid vaccine. Among the uninoculated 
 officers a minimum of ten deaths occurred, instead of five as 
 recorded. When due allowance is made for these errors, the 
 case-mortality of the inoculated works out distinctly lower than 
 that of the uninoculated. 
 
 No. 5. A. The number of inoculated is represented to be 
 the number inoculated since rendering previous returns ; the 
 number of uninoculated is calculated by subtracting these from 
 the total average strength of the garrison. The statistical 
 results are rendered unduly favourable to the uninoculated by 
 the fact that among these are included in the records 234 
 men (nth Hussars) inoculated in India (1889) and a balance 
 of 463 men inoculated in Egypt (1889). There were no 
 cases of typhoid in either of these groups. F. The only case
 
 ANTI-TYPHOID INOCULATION. 59 
 
 of typhoid fever among the inoculated was a fatal case in a 
 man inoculated on December 8, 1899, and admitted to hospital 
 January 9, 1900. If it had not been for this case, the incidence 
 on the inoculated, numbering probably over 1,000, would have 
 been nil. G. The fact that no case of typhoid occurred among 
 those inoculated in the previous year seems to indicate a 
 persistence of the protection. H. The number of the inoculated 
 in the West Kent Regiment (228), given as representing men 
 newly inoculated, is identical with the number from that 
 regiment reported as inoculated in the previous year. This 
 suggests a mistake in the entry. 
 
 No. 6. A. The number of inoculated was obtained by 
 adding together the numbers reported from the separate 
 stations ; it thus happened that in some cases men were 
 counted twice over, being returned from two places. It is 
 estimated that the total of the inoculated may be wrong by 
 at most " some hundreds." The numbers of the uninoculated 
 are in some cases actuals, in others they are obtained by 
 subtraction of inoculated from the average yearly strength 
 of units. B. D. The conditions for the most part are as under 
 No. 2. In the case of some at least of the 2,246 men inocu- 
 lated in 1900 the period of exposure after inoculation must 
 have been less than a complete year. F. In the case of three 
 of the inoculated who contracted typhoid, the attacks super- 
 vened respectively 15, 15 and 24 days after inoculation. The 
 first of these cases ended fatally. If these had been deducted, 
 the incidence and death-rate among the inoculated would 
 have been slightly reduced the case-mortality from i in 6-5 
 to i in 7. G. Of the 52 cases of typhoid which occurred 
 in the. inoculated in 1900, 21 occurred among the 2,250 inocu- 
 lated in 1900, and 31 among the 3,750 inoculated in 1889. 
 These figures suggest that the protection persists for more than 
 a year. 
 
 Xo. 7. A and D. No data are available as to procedure 
 adopted for purpose of classifying the patients into inoculated 
 and uninoculated. c. The case-mortality (i : 53) attributed 
 to the uninoculated is suspiciously low for typhoid fever. 
 The case-mortality of the inoculated (i : 15) corresponds with 
 that found elsewhere in South Africa. H. The total typhoid 
 case-mortality of the hospital in which Dr. Melville served
 
 60 ANTITYPHOID INOCULATION. 
 
 in the months which are covered by his period of observation 
 was i in 5*4, not i in 40 as would appear from Dr. Melville's 
 figures. (Major S. Westcott, letter to British Medical Journal, 
 July 30, 1901.) 
 
 No. 8. A. and D. The classification of the sick into inocu- 
 lated and uninoculated was controlled by a careful triple check. 
 c. Major C. Birt, R.A.M.C., confirmed the diagnosis in all fatal 
 cases by necropsy, and all cases of doubtful diagnosis were 
 omitted from the records. 
 
 Nos. 9 to 12. A. and D. No data available as to procedure 
 adopted for the purpose of classifying the patients into inocu- 
 lated and uninoculated. c. Diagnosis made by the physicians 
 attached to the hospitals. 
 
 No. 13. A. and D. In most cases entries were made in the 
 case of the inoculated, and blanks were left in the records 
 of the uninoculated. Cases transferred from one hospital to 
 another are omitted from the statistics, c. As in No. 2. 
 
 D. Errors of classification may have occurred owing to state- 
 ments made in misapprehension by patients who had been 
 vaccinated against small-pox on the transports, or to erroneous 
 statements made by patients who desired for the purpose of 
 avoiding inoculation to represent themselves as inoculated. 
 
 E. Both officers and men are included in the statistics, the 
 former having, perhaps, a better chance of recovery ; but as 
 both classes occur in each group, there is no resulting source of 
 error. H. Dr. Dodgson's report which sets forth the figures 
 collected from the Military Hospitals affords evidence of con- 
 scientious compilation and the exercise of a critical spirit in 
 dealing with statistical records which were often vitiated by 
 serious errors. 
 
 Nos. 14, 15, and 16. A. Presumably nominal rolls. B. No 
 data as to age and period of exposure in the two groups 
 c. The diagnoses were made by the physicians attached to the 
 hospital. 
 
 No. 17. A. Nominal rolls. B. The conditions of the three 
 hospitals whose inoculated and uninoculated staff are here com- 
 pared were similar ; the incidence rate among the uninoculated 
 members was in No. 8, 40 per cent., in No. 9, 28 per cent., 
 and in No. 10, 30 percent. F. Four cases (none fatal) occurred 
 between the third and the fourth week after inoculation.
 
 ANTI-TYPHOID INOCULATION. 61 
 
 No. 1 8. A. The uninoculated in the second section probably 
 numbered less than 12. B. As in 14-16 supra. D. As in No. i. 
 
 No. 19. A. Presumably nominal rolls. B. Conditions the 
 same. c. and D. Diagnosis was in each case made by Lieut. 
 J. W. Wells, who remained with the regiment after carrying out 
 the inoculations. 
 
 No. 20. No data beyond those included in the Table. 
 
 No 21. A. Nominal rolls were made of the patients as they 
 were inoculated in a series of separate sittings. From these 
 and from a list of the cases and dates of attack the average 
 strength of the inoculated and the uninoculated was calculated, 
 for the period covered by the epidemic. B. No data as to age. 
 The average age of the nurses (uninoculated) may probably 
 have been less than that of the patients. The external con- 
 ditions of both groups were similar, but the nurses (unin- 
 oculated), though living among the insane patients, would 
 avoid risks incurred by the latter. Reckoned by the incidence 
 of cases among the uninoculated, the risk of coming in contact 
 with infection was greater after the date at which the number 
 of inoculated reached the number taken as the average strength 
 than it was before this date. c. and D. No source of error. 
 F. Of a total of 6 cases of typhoid fever which developed in the 
 inoculated, 5 occurred within twelve days of inoculation ; i of 
 these ended fatally. If these cases had been deducted, the 
 incidence on the inoculated group would have been 30- (instead 
 of 6-) fold less than on ths uninoculated. 
 
 No. 22. A. The inoculated and the uninoculated represent 
 two chance groups marked off by the accident of invaliding 
 from the large bodies of inoculated and uninoculated officers 
 \vho saw service in South Africa. The statistics are vitiated in 
 favour of the uninoculated, for seeing that the typhoid case- 
 mortality of the inoculated is, as is brought out by the sum 
 total of the available statistics, 50 per cent, lower in the 
 inoculated, more of these would survive to return home. 
 B. The uninoculated were probably older and by reason of 
 their age less susceptible (see next paragraph). C. and D The 
 classification of the patients as convalescents from typhoid 
 depended upon the reports they rendered of the diagnoses 
 arrived at in South Africa. F. One twice-inoculated officer 
 contracted typhoid within a month of landing in South Africa.
 
 62 ANTI-TYPHOID INOCULATION. 
 
 G. A table in Colonel Crombie's report suggests that the effect 
 of inoculation diminishes after the expiration of six months. 
 
 No. 23. A. As in No. 22. B. The average age of the 
 inoculated was 25-4 years, that of the uninoculated 30*6. 
 c. and D. As in No. 22. 
 
 No. 24. A. Nominal rolls, c. and D. The classification 
 into inoculated and uninoculated, and the facts with regard to 
 incidence and case-mortality were very carefully controlled by 
 Captain W. A. Ward, R.A.M.C., who conducted the inoculations 
 and remained in medical charge of the regiment. 
 
 No. 25. A. The number of the inoculated and uninoculated 
 corresponds in each case with the average strength of the group 
 determined by taking into account the number of days during 
 which each soldier was under observation. B. to E. As in 
 No. 2. F. No data. G. The statistics here in question refer 
 almost exclusively to men inoculated in 1898, 1899, and 1900. 
 So far as they apply to men inoculated in 1900, they confirm 
 the statistics of that year, which showed that the protection 
 conferred by inoculation persisted during the second term of 
 twelve months. So far as the statistics of 1901 refer to a 
 residue of the. 4,000 men inoculated in India in 1898-1899 they 
 suggest that the protective effect of inoculation is maintained 
 for a minimum of three years. 
 
 No. 26. No data beyond those included in the Table. 
 
 No. 27. No data beyond those included in the Table. 
 
 GENERAL CONCLUSIONS WHICH EMERGE FROM THE SUM 
 TOTAL OF STATISTICAL RECORDS. 
 
 It will be well to make clear before proceeding to summarise 
 the teaching of the statistical materials embodied in the table 
 above that the inoculations whose results are here recorded 
 represent inoculations undertaken for the most part in a very 
 hurried manner, under very difficult external conditions, with 
 imperfectly standardised vaccines, and particularly in the case 
 of the South African inoculations, by agents who were abso- 
 lutely without scientific training. 1 Further the results here 
 recorded were obtained for the most part by the inoculation 
 
 1 This defect of training was exhibited in the fact that great liberties were 
 taken in the matter of the dose inoculated, further in the fact that the essential 
 element of the vaccine, the bacterial deposit, was often left at the bottom of 
 the bottle, the supernatant fluid being alone employed.
 
 ANTI-TYPHOID INOCULATION. 63 
 
 of a single large dose of vaccine. If, as will be plain from 
 the analysis of the results which is given below, inoculations 
 conducted under all these disadvantages have none the less 
 furnished clear evidence of the utility of the process, and if, 
 as will be manifest, the process has in spite of the imperfect 
 manner in which it has been carried out already effected 
 a great saving in life, it is perhaps not over-sanguine to look 
 forward to the achievement of a very much greater protective 
 effect when provision shall have been made for carrying on the 
 inoculations in a manner more in accordance with the demands 
 of a scientific system. 
 
 For the moment, however, we are concerned, not with the 
 future, but with what has already been achieved. 
 
 Effect which has been exerted by anti-typhoid inoculation on 
 the incidence of the disease. 
 
 A study of the statistical material will show that in every 
 case, except that of the City Imperial Volunteers (where the 
 statistical materials at my disposal consist only of the bald 
 figures incorporated in the table), and in the case of the staffs 
 of the Portland Hospital and Imperial Yeomanry Branch 
 Hospital at Pretoria (where we are dealing with very small 
 figures), the incidence of typhoid fever was diminished by at 
 least one-half in the inoculated. In certain cases, notably in 
 those to which the statistics designated by the serial numbers 
 3, 4, 5, 1 8, and 21 apply, a greater reduction in the incidence 
 of typhoid fever was achieved a reduction varying from a 
 6-fold to a 28-fold reduction. 
 
 Effect which has been exerted by anti-typhoid inoculation 
 on the case-mortality of the disease. Superadded to the dimi- 
 nished incidence of the disease there is a striking diminution 
 of case-mortality, as is attested by the extensive statistical 
 material collected by Dr. R. W. Dodgson (Table I., No, 13), 
 from various Military Hospitals, and more particularly by the 
 accurate and extensive figures obtained at Harrismith under 
 the zealous personal supervision of Major C. Birt, R.A.M.C. 
 (Table I., No. 8), and in the Civil Hospitals (Tables I. and II., 
 Nos. 9, 10, n, 12, 14) in South Africa. In the aggregate 
 the proportion of deaths to cases among the inoculated has 
 been rather less than half that among the uninoculated. 
 
 Taking the figures in the Table exactly as they stand, it
 
 64 ANTI-TYPHOID INOCULATION. 
 
 will be found that 1,758 inoculated patients furnished 142 
 deaths (8*0 per cent.), while 10,980 uninoculated patients 
 furnished 1,800 deaths (i6'6 per cent.). 
 
 Effect which has been exerted by anti-typhoid inoculation 
 on the death-rate from the disease. The combined effect of the 
 diminished incidence and diminished case-mortality manifests 
 itself in the diminished death-rate from typhoid fever among 
 the inoculated. The minimum reduction of death-rate chronicled 
 in the table is the twofold diminution in the case of the City 
 Imperial Volunteers. As will be seen, the reduction of death- 
 rate in case of the inoculated has often exceeded, and has 
 seldom fallen below, a four-fold reduction. 
 
 Duration of the protection which is conferred by anti-typhoid 
 inoculation. The only definite statistical evidence which is 
 available for the decision of the question as to the duration 
 of the protective effect exerted by anti-typhoid inoculation is 
 to be found in the statistical returns of the ) r ear 1900, relating 
 to the British Garrisons in India and Egypt respectively. 
 (Synoptical Table, Nos. 6 and 5.) This evidence, so far as it 
 goes, points to the persistence of the protective effect during 
 the second year after inoculation. 
 
 The statistics relating to the British garrison in India 
 (Synoptical Table, No. 25) for the year 1901 make it probable 
 that the effect of the inoculation persists during the third year. 
 
 Attention may be directed in this connection to two series 
 of laboratory observations which afford a certain amount of 
 support to the conclusions just arrived at : 
 
 (a) It is not infrequent to find an agglutinating power in 
 the blood of inoculated persons as long as two years after the 
 inoculation of anti-typhoid vaccine. 
 
 () Von Dungern's experiments ' in connection with rabbits 
 inoculated with crab's blood have shown that even after the 
 specific antitropic substances which have been produced by 
 inoculation have disappeared from their blood, the inoculated 
 animals retain a power of responding more rapidly and more 
 effectively to a renewal of the vaccinating stimulus. 
 
 1 Loc. cit.
 
 ANTI-TYPHOID INOCULATION. 
 
 APPENDIX I. 
 
 DETAILED DESCRIPTION OF THE PROCEDURE 
 
 EMPLOYED FOR PREPARING AND STANDARDISING 
 
 ANTI-TYPHOID VACCINE. 
 
 CULTIVATION FLASKS. 
 
 For the purpose of cultivation flasks of the pattern shown in Fig. i are 
 employed. These flasks are, as will be seen, furnished with a lateral tube, 
 to which is fitted a piece of perfectly sound 
 vulcanised rubber, pressure tubing. The orifice 
 of this last is blocked with a piece of glass rod, 
 and is fitted with a pinch cock (see figure) in 
 such a manner that the distal end of the tube 
 remains free from fluid. 
 
 The advantages which are associated with 
 the employment of cultivation flasks fitted in 
 this manner are the following : The flasks can 
 easily and rapidly be inoculated by puncturing 
 through the pressure tubing with the needle 
 of a syringe which has been filled with a pure 
 culture of typhoid. In doing this, as a precaution 
 against the introduction of contaminations, the 
 
 Fig. i. Cultivation 
 flask. 
 
 outside of the tubing, at the point where it is to be punctured, is first sterilised 
 by the application of a piece of glass rod which has been raised to a dull red 
 heat. After withdrawing the needle the minute puncture hole can readily 
 be sealed up by reapplying the heated glass. Further advantages which are 
 associated with the use of these flasks are (a) the possibility of withdrawing 
 samples at any time with a view to controlling the purity of the cultures, 
 and (&) the possibility of transferring, without exposure to the air, the 
 contents of the cultivation flasks to the larger jars (Fig. 2) employed in the 
 processes of preparation which are described below. 
 
 CULTIVATION MEDIUM AND PERIOD DURING WHICH THE CULTURES 
 ARE INCUBATED. 
 
 The flasks, after having been inoculated, are transferred to an incubator, 
 which is kept at blood temperature, ordinary i per cent, peptone broth, 
 accurately neutralized and disposed in a shallow layer, furnishes the best 
 cultivation medium. The cultivation is continued for a maximum of 48 hours.
 
 66 
 
 ANTI-TYPHOID INOCULATION. 
 
 MODE OF FITTING UP THE MIXING JARS IN WHICH THE CULTIVATIONS 
 ARE STERILISED BY HEAT. 
 
 After the purity of each flask has been ascertained by culture, the contents 
 of the cultivation flasks are transferred to the larger jars (Fig. 2). This 
 transference is undertaken first with a view to mixing together the contents 
 of a series of cultivation flasks, so as afterwards to standardise them in bulk ; 
 secondly, it is undertaken with a view to eliminating the possibility of the 
 vaccine becoming spontaneously reinoculated with living bacilli after it has 
 been exposed to heat. This possibility would exist if there were to be found 
 on the sides or neck of the flask, when it is transferred to the water bath, any 
 typhoid bacilli which had been rendered by desiccation less sensitive than they 
 would otherwise be to the heat which is there brought to bear on them. 
 
 Before describing the process of transferring the typhoid cultures from one 
 flask to anothe r , and the subsequent processes of heating and mixing, it will 
 be necessary first briefly to describe the manner in which the larger " mixing " 
 jars are fitted up. 
 
 The lateral tubes are fitted with vulcanised rubber pressure tubing, which 
 is blocked in each case with glass rod. A clamp is further placed on each 
 tube. Through the lowest of the lateral tubes the contents of the cultivation 
 flasks are introduced into the mixing jar. The upper tube is appropriated to a 
 paraffin thermometer which is employed for the purpose of notifying the 
 point at which the internal temperature of the typhoid culture has reached 
 
 Pig t 2. Large jars connected together for the purpose of mixing the 
 
 vaccine. Paraffin thermometers which have sunk are shown at the 
 
 bottom of each mixing jar.
 
 ANTI-TYPHOID INOCULATION. 
 
 60 C. The prmciph and the mode of using these thermometers require a 
 word or two of explanation. 
 
 A- -h 
 
 Fig. 3. Paraffin thermometer in position against inner wall of mixing jar. 
 A, Upper end of thermometer, left open; B, bulb ; C, fusiform enlarge- 
 ment filled in with paraffin of the appropriate melting point ; D, constricted 
 portion of the stem engaged in wire snare; E, lower sealed end of thermo- 
 meter ; F, wall of mixing jar; G, upper lateral tube of mixing jar ; 
 H, distal end of wire snare engaged between the rubber tube (l) and the 
 glass rod (j) which blocks the tube. 
 
 CONSTRUCTION AND MODE OF EMPLOYING THE PARAFFIN 
 THERMOMETERS. 
 
 The construction of the paraffin thermometer will readily be understood 
 from a consideration of Fig. 3 which represents the thermometer in position 
 in the mixing jar. It will be seen that the thermometer consists essentially of 
 a glass bulb or float which is left open at the top. This glass bulb runs out 
 below into a hollow glass stem, which is filled in with pa affin through its 
 lower end. When the thermometer is brought into use the bulb floats on 
 the surface of the fluid. The paraffin chamber, acting as a sinker, causes 
 the thermometer to stand up in the fluid somewhat like a fisherman's float. 
 When the temperature of the surrounding fluid rises to 60 C. (or to such other 
 point as corresponds to tlu melting point of the particular paraffin which is 
 employed), the melting paraffin is pressed upwards against the upper part of 
 
 F
 
 68 ANTI-TYPHOID INOCULATION. 
 
 the paraffin chamber by the pressure of the fluid. Owing, however, to the 
 fusiform shape which is given to this chamber (Fig. 3, c), the fluid cannot pass 
 up into the stem until the paraffin actually melts. As soon as this occurs the 
 fluid enters the upper bulb or float and the thermometer sinks to the bottom. 
 
 These thermometers having been devised, the only difficulty which 
 presented itself was that of so disposing matters as to allow of the thermo- 
 meter being sterilised in situ. This object is effected by sealing up the lower 
 end of the thermometer (Fig. 3, E) so as to prevent the paraffin escaping 
 during the process of sterilisation. The further problem of snapping off 
 the sealed end of the thermometer without opening up the sterilised jar is 
 satisfactorily solved by the following device. 
 
 When the jar is being fitted up, previous to sterilisation, a noose of fine brass 
 wire is passed in through the rubber tube which is connected with the upper- 
 most lateral tube of the mixing jar. 
 
 Fi. 4. Transverse section of mixing jar at the level of the uppermost 
 lateral tube, showing method of fixing the paraffin thermometer. A, Noose 
 of brass wire engaging the constricted part of the stem of the thermo- 
 meter j B, end of lateral tube ; c, glass rod plugging the end of the rubber 
 tube ; D, free end of the wire clamped in position by the rod C. 
 
 This noose is brought up to the neck of the jar, and the sealed capillary end 
 of the thermometer is engaged in it in such a manner that the noose fits into 
 a constriction shown in the diagram (Fig. 3, D). The noose is now drawn 
 gently home until the thermometer becomes fixed, opposite the orifice of the 
 lateral tube. x It only remains to fasten the free extremity of the wire. This 
 is effected by inserting a piece of tightly-fitting glass rod into the end of the 
 tube in such a manner as to engage the wire between the rod and the wall 
 of the tube (Figs. 3 and 4). This done, a rubber bung, which is perforated 
 by a recurved glass tube plugged with cotton wool, is inserted into the neck 
 of the jar, and is tied in tightly. The jar is now ready for autoclaving. 
 
 METHOD OF MIXING TOGETHER THE CONTENTS OF A SERIES OF 
 
 CULTIVATION FLASKS AND OF KILLING THE CULTURE. 
 
 When the jar has been autoclaved, and when the bung has afterwards 
 
 been duly luted with sterilised paraffin, the subsequent procedure is as 
 
 follows : A cultivation flask is taken in hand, the end of the attached rubber 
 
 tubing is sterilised in the flame, and the glass rod which blocks the orifice is
 
 ANTI-TYPHOID INOCULATION. 69 
 
 withdrawn in an aseptic manner. In a similar manner the glass rod which 
 blocks the lowest of the three lateral tubes of the mixing jar is withdrawn. 
 This done, a connection is, by means of a sterilised glass union, established 
 between the two tubes, the clamps are withdrawn, and the fluid passes out 
 from the cultivation flask into the mixing jar. As soon as a certain amount 
 of fluid has entered the mixing jar, and at any rate before the fluid has 
 reached the level of the uppermost lateral tube, the pressure tubing which is 
 attached to this side tube is gently pulled. This causes the wire noose which 
 is round the capillary end of the paraffin thermometer to snap this off by a 
 guillotine action. The released thermometer then drops into the fluid, ready 
 for use. The brass wire which has fulfilled its office is now grasped with a 
 forceps, and is withdrawn from the tube. 
 
 When the contents of a cultivation flask have passed into the mixing 
 jar, the clamp belonging to the mixing jar is replaced upon the rubber tube 
 at a point proximal to the glass nozzle which connects the two parts. The 
 needle of a syringe which has been filled with undiluted carbolic acid is 
 then inserted into the lumen of the tube at a point between the clamp and the 
 glass nozzle which was referred to above. The syringeful of carbolic acid 
 is then driven through the tube into the cultivation flask. This done, the 
 cultivation flask may be disconnected without risk. The next cultivation flask 
 in the series is now taken in hand in the same manner. When the process of 
 filling in the mixing jar has been completed the side tubes are blocked with 
 pieces of sterilised glass rod. These are luted with rubber solution. 
 
 The next proceeding is to transfer the mixing jar or jars to the water bath. 
 This is to be done without delay, and the jars are to be carried in such a 
 manner as to avoid all splashing up of the culture on to the sides and neck of 
 the jar. The water bath must be deep enough to allow of the water coming 
 well over the shoulder of the mixing jar. This last is not to be filled within 
 2 inches of this level. If the jar, when it is introduced into the water bath, is 
 found to be buoyant, it is weighted down by passing a heavy leaden collar 
 round its neck. The jars having been securely placed in position, heat is 
 applied to the water bath, and the condition of the thermometers in the 
 separate jars is noted from time to time. This is best done by lowering a 
 pkce of ordinary looking-glass below the surface of the water in the water 
 bath. The gas is turned out as soon as the paraffin thermometer has sunk. 
 The jar of vaccine remains in the hot water for another 10 to 15 minutes. 
 
 The next step is to mix the contents of the whole series of mixing jars 
 so as afterwards to obtain for standardisation a representative sample of 
 the whole brew of vaccine. The mixing is effected by connecting up the 
 mixing jars with each other by means of their rubber tubes (Fig. 2). These 
 rubber tubes are of such length as to allow of any one of the jars being freely 
 raised above or lowered below the level of its companion jars. By these 
 means complete mixture of the contents is readily effected. In cases where 
 the mixing jars are so full as to place a difficulty in the way of the satisfactory 
 mixture of their contents, an additional empty sterilised mixing jar is intro- 
 duced into the circuit. Mixture having been duly effected, samples of the 
 vaccine are withdrawn in the mauntr described above in connection with the
 
 70 ANTI-TYPHOID INOCULATION. 
 
 control of the purity of the contents of the cultivation flasks. The sterility of 
 the samples of vaccine is of course tested by introducing them both into tubes 
 of broth and into tubes of nutrient agar. 
 
 After this has been done further samples are drawn off for the purpose 
 of determining the strength of the vaccine. An addition of antist ptic is 
 now made to the vaccine with a view to preserving it against risk of sub- 
 sequent contamination. An addition of one-tenth of its bulk of a 5 per 
 cent solution of lysol or carbolic answers this purpose very well. A simple 
 method of making this addition is to take the required quantity of water 
 and to sterilise it in a Kitasato flask fitted with a length of vulcanised pressure 
 tubing. After sterilisation the appropriate quantity of carbolic acid is intro- 
 duced into this flask by puncturing through the pressure tubing. The Kitasato 
 flask is now connected up with the series of mixing jars which contain the 
 vaccine, and the antiseptic is thoroughly mixed up with the vaccine. It is 
 inexpedient to add undiluted carbolic acid directly to the vaccine, inasmuch as 
 it causes the bacteria to run together into large masses. 
 
 STANDARDISATION OF THE VACCINE. 
 
 As has been indicated when this subject matter was under consideration 
 in Chapter III. above, the vaccine can be standardised in a satisfactory manner 
 by the enumeration of the typhoid bacilli contained in the unit of volume. 
 
 This enumeration can in the case of a 24 48 hour culture of the bacillus 
 typhosus be made in an accurate and expeditious manner under the microscope 
 by the method described by me in the Lancet, July 5, 1902. 
 
 The figure below will illustrate the method. It will be manifest that in the 
 case where we are dealing with a mixiure of an aliquot volume of normal ' 
 blood (containing 5,000,000,000 red blood corpuscles per cubic centimetre) with 
 an equal volume of a bacterial culture, the number of micro-organisms and red 
 blood corpuscles in a film prepared with such a mixture will stand one to 
 the other in the ratio which corresponds to the respective numbers of red 
 corpuscles and bacilli in the unit of volume. 
 
 The mixture of the blood and culture in definite proportions is made as 
 follows. 2 We take in hand a piece of glass tubing, heat it and draw it out into 
 a capillary stem of convenient size. We provide ourselves with a glass-writing 
 pencil and a rubber teat which will fit tightly upon the upper end of our tube. 
 Having placed a mark upon the capillary stem at a convenient distance from 
 its orifice, and having by means of the teat established a negative pressure in 
 the interior of the tube, we draw up in succession into the capillary stem (a) one 
 volume of blood (obtained from a prick in the finger) such as will fill the 
 capillary stem up to the fiduciary mark ; (b) an air bubble to serve as an index ; 
 (c) a volume of the vaccine, (d?)and further three volumes of a physiological 
 salt solution ; or, in lieu of these last, as may be required, one, two, or three 
 further volumes of the vaccine ; taking care to complete in each case to five 
 
 1 Where only blood which exerts an agglutinating action on the typhoid bacillus is available, 
 the difficulty which arises may be circumvented by heating the culture of typhoid to the point at 
 which the agglutinable substance is destroyed. 
 
 2 Examples of the employment of the different mixtures here in question will be found 
 tabulated in Table I., appended to my original paper.
 
 ANTI-TYPHOID INOCULATION. 
 
 volumes. Having expelled the contents of the tube on to a slide, and having 
 effected thorough mixture by drawing up the fluid into the capillary pipette and 
 blowing it out several times in succession, we transfer a drop of the mixture to 
 a microscopic slide 1 and spread it out by bringing down upon it the edge of 
 another slide and drawing this along. The thickness of the him is regulated 
 by adjusting the angle between the slides, widening this angle when a thicker 
 film is to be left behind, and narrowing it when a thinner film is required 
 The film is then fixed and sta ned, most conveniently, perhaps, by the stain 
 described by my sometime colleague, Major W. B. Leishman, R.A.M.C. The 
 bacteria and red blood corpuscles are now separately enumerated on a series 
 of fields chosen at random from different pa; ts of the preparation. Owing to 
 the spacing out which is secured by the five-fold dilution of the blood this 
 enumeration can, if necessary, be carried out without restricting or subdividing 
 the field of the microscope. It, however, facilitates matters if we restrict the 
 field by the employment of a high-power eye-piece and subdivide it by 
 inscribing a cross by means of a glass writing pencil upon a cover-glass and 
 dropping this into the eye-piece. The necessary calculations can be most 
 easily carried out by the help of a slide rule. 
 
 The method of calculation will be rendered intelligible on considering the 
 figure below. 
 
 Film preparation made from a mixture of a (measured volume of normal 
 blood with a measured volume of typhoid culture. 
 
 1 The slide may with advantage have been prepared immediately before use by pouring 
 alcohol upon it and burning this off. The same object can be achieved by boiling the slide in 
 s.ron;- caustic soda.
 
 72 ANTI-TYPHOID INOCULATION. 
 
 We have here represented a typical field of such a film preparation as has 
 been described above. It will be found that there are here contained in this 
 field of view 36 red blood corpuscles and 20 typhoid bacilli. Making the 
 assumption that we are here dealing with a normal Wood and as already 
 postulated with an average field, the calculation we make is as follows : 
 
 Number of red blood corpuscles in average field : number of bacilli in 
 average field :: number of red blood corpuscles in the unit of volume : number 
 of bacilli in the unit of volume. 
 
 36 : 20 :: 5,000,000,000 number of bacilli in the cubic centimetre of culture : 
 answer : The culture contains circ. 2,800,000,000 typhoid bacilli in the 
 cubic centimetre. 
 
 In the case where, in lieu of i volume, 2, 3, or 4 volumes of culture have 
 been mixed with one volume of blood the number of bacilli in the cubic centi- 
 metre of culture will of course correspond to the quotient obtained by dividing 
 the result arrived at in the above calculation by, as the case may be, 2, 3, or 4. 
 
 Bottling the Vaccine. 
 
 In order to reduce to a minimum the possibility of aerial contamination 
 during the operation of bottling,, the vaccine is by the following procedure 
 run from the large jars directly into bottles without being at any time exposed 
 to the air. 
 
 In the first place a number of small bottles, of a shape and capacity best 
 suited to the requirements of the case, are plugged with cotton-wool and 
 autoclaved. 
 
 When the autoclaved bottles are cool the cotton-wool plugs are replaced 
 under antiseptic precautions by strong rubber caps, which have been soaked 
 in a saturated solution of perchloride of mercury, and which have been 
 specially made to fit the bottles. The use of these rubber caps, in preference 
 to any form of cork or stopper, presents many advantages, chief among them 
 being the fact that they admit of all fluids being introduced into, or withdrawn 
 from, the bottle without further opening than that made by the introduction of a 
 hypodermic needle an obvious gain when we consider the danger of contami- 
 nation which occurs every time a bottle is corked or uncorked. 
 
 A sufficient number of bottles having been prepared in this manner, one of 
 the mixing jars is now taken in hand. The lowest of the lateral tubes is now 
 connected by means of a glass nozzle with a length of sterilised rubber tubing, 
 terminating in a T tube fitted up by means of further lengths of rubber 
 tubing with two hypodermic needles. To the plugged air tube which passes 
 through the top of the missing jar is now attached an ordinary hand bellows, 
 such as belongs to any spray-producing apparatus. This is done with a view 
 to accelerating by air pressure the flow of the vaccine as it passes out through 
 the hypodermic needles. In order to prevent the paraffin with which the 
 rubber bung is luted from yielding to air pressure when this comes to be 
 applied, it is well to coat over every part of the bung with a layer of collodion, 
 which should be allowed to set before pressure is applied. The hypodermic 
 needles are now withdrawn from the test tubes in which they have been 
 sterilised, and we proceed to fill in the bottles, The first operation is to get
 
 ANTI-TYPHOID INOCULATION.' 
 
 73 
 
 up a slight amount of air pressure in the interior of the jar by working the 
 bellows. This done the caps which cover the bottles are dipped in a strong 
 solution of carbolic acid or lysol. A vent is now provided for the air, which 
 
 Fig. 6. Method of filling small bottle from the mixing jar. A. Hypo- 
 dermic needle connected with the tube C leading from the mixing jar ; 
 B. second hypodermic needle forming an outlet for the air. 
 
 will be displaced by the vaccine by piercing the cap of each bottle as it is dealt 
 with by a very fine hypodermic needle, which has just been removed by means 
 of a forceps from a vessel of oil at a temperature exceeding ioc C.' (Fig. 6). 
 The clamp on the rubber tubing which leads off from the mixing jar is now 
 taken off, and the pressure of the fingers is substituted for it. The flow of the 
 vaccine is now under perfect control, the hypodermic needle is introduced 
 through the cap into the bottle, and the vaccine is then allowed to flow in 
 (Fig. 6). In this manner any number of bottles of vaccine can be quickly 
 filled, without the fluid ever coming in contact with the external air. The 
 contents of the mixing jar are shaken up from time to time during the course of 
 the operation. 
 
 When the bottles have been filled, it remains to repair the microscopic 
 punctures in the rubber caps and to coat them with a protecting envelope of 
 paraffin. For this purpose the solution of rubber which is sold for the purpose of 
 repairing bicycle tyres is employed. Before applying it to the cap of the bottle, 
 the remains of the antiseptic solution are first cleaned off by absolute alcohol, 
 and then the rubber is freed from all traces of grease by means of ether. When 
 the rubber solution has hardened, each bottle is further protected by coating 
 the whole tap with paraffin, which has been previously raised to a temperature 
 of 1 60 C. A paraffin with a high melting point is selected if the vaccine js 
 to be sent to a tropical climate. In dipping the bottles into the melted paraffin 
 it is well to immerse the whole cap, so that the 'paraffin may fill up the 
 interspace between the base of the cap and the neck of the bottle. 
 
 To withdraw the vaccine from one of the bottles for inoculation it is only 
 necessary to sterilise the cap in hot oil, or, better, in a hot antiseptic solution, 
 and to insert a sterile syringe through the rubber cap. After the first puncture 
 ihe needle is withdrawn and then reinserted and the syringe filled. The first 
 perforation is made for the purpose of acting as an air valve to permit the 
 entrance of air to replace the fluid withdrawn.
 
 74 ANTI-TYPHOID INOCULATION. 
 
 APPENDIX II. 
 
 LIST OF AUTHORS PAPERS DEALING WITH IMMUNISATION 
 AGAINST BACTERIAL DISEASES ; ANTI-TYPHOID INOCU- 
 LATION ; THE MEASUREMENT OF THE CONTENT OF THE 
 BLOOD IN PROTECTIVE SUBSTANCES J AND KINDRED 
 SUBJECTS. 
 
 Wright. On Wooldridge's method of producing immunity against anthrax 
 by the injection of solutions of tissue-fibrinogen. British Medical Journal, 
 September 19, 1891. 
 
 Wright and Bruce. On Haffkine's method of vaccination against Asiatic 
 cholera. British Medical Journal, February 4, 1893. 
 
 Wright and Semple. On the presence of typhoid bacilli in the urine 
 of patients suffering from typhoid fever. Lancet, July 27, 1895. 
 
 Wright. On the association of serous haemorrhages with conditions of 
 defective blood-coagulability. Lancet, September 19, 1896. 
 
 (In this paper, which treats inter alia of the local effects produced 
 by anti-typhoid inoculation, the details of the two first anti-typhoid 
 inoculations conducted upon man are placed upon record.} 
 
 Wright. Note on the technique of serum diagnosis of acute specific 
 fevers. British Medical Journal, January 16, 1897. 
 
 Wright and Semple. Remarks on vaccination against typhoid fever. 
 British Medical Journal, January 30, 1897. 
 
 Wright and Sm'.th. On the application of the serum-test to the differential 
 diagnosis of typhoid and Malta fever. Lancet, March 6, 1897. 
 
 Wright. A further note on the technique of serum-diagnosis. British 
 Medical Journal, February 5, 1898. 
 
 Wright and Lamb. Observations on the question of the influence which 
 is exerted by the agglutinins in the infected organism. Lancet, December 23, 
 
 1899. 
 
 Wright and Leishman. -Remarks on the results which have been obtained 
 by the anti-typhoid inoculations, and on the methods which have been 
 employed in the preparation of the vaccine. British Medical Journal, 
 January 20, 1900. 
 
 Wright. On a method of measuring the bactericidal power of the blood 
 for experimental purposes. (First communication.) Lancet, December i, 
 1900. 
 
 Wright (conjointly with other Members of the Indian Plague Commission). 
 On Haffkine's 'anti-plague inoculation Report of Indian Plague Com- 
 mission, 1901.
 
 ANTI-TYPHOID INOCULATION. 75 
 
 Wright. On the quantitative estimation of the bactericidal power of the 
 blood (second communication.) Lancet, March 2, 1901. 
 
 Wright. On the changes effected by anti-typhoid inoculation in the 
 bactericidal power of the blood with remarks on the probable significance 
 of these changes. Lancet, September 14, 1901. 
 
 Wright. On the results obtained by anti-typhoid inoculation in the case 
 of an epidemic of typhoid fever which occurred in the Richmond Asylum, 
 Dublin. British Medical Journal, October 26, 1901. 
 
 Wright. Notes on the treatment of furunculosis, sycosis, and acne by the 
 inoculation of a staphylococcus vaccine ; and generally on the treatment of 
 localised bacterial invasions by therapeutic inoculations of the corresponding 
 bacterial vaccines. Lancet, March 29, 1902. 
 
 Wright. On some new procedures for the examination of the blood and 
 bacterial cultures. Lancet, July 5, 1892. 
 
 (Includes a description of a method of determining tinder the microscope 
 the number of micro-organisms contained in a bacterial culture.) 
 
 Wright. Synopsis of the results which have been obtained by anti-typhoid 
 inoculation. Lancet, September 6, 1902. 
 
 Wright and Windsor. On the bactericidal effect exerted by human blood 
 on certain species of pathogenic micro-organisms, and on the anti-bactericidal 
 effects obtained by the addition to the blood in vitro of dead cultures of the 
 micro-organisms in question. -Journal of Hygiene, Vol. II., No. 4, October, 
 1902. 
 
 Wright. On the measurement of the bactericidal power of small samples 
 of blood under aerobic and anaerobic conditions, and on the comparative 
 bactericidal effect of human blood drawn off and tested under these contrasted 
 conditions. Proc. Royal Society, Vol. 71, 1902. 
 
 Wright and Knapp. Note on the causation and treatment of thrombosis 
 occurring in connection with typhoid fever. Transactions of the Medico- 
 Chirurgical Society, Vol. 86, and Lancet, December 6, 1902. 
 
 Wright. On the bacteriolytic power of the blood and on its relation to the 
 problems of anti-typhoid inoculation and the recent work of Dr. Macfadyen. 
 British Medical Journal, April 4, 1903. 
 
 Wright. A note on the serum reaction of tubercle with special reference 
 to the intimate nature of agglutination reactions generally and to the thera- 
 peutic inoculation of the new tuberculin. Lancet, May 9, 1903. 
 
 Wright. A lecture on the therapeutic inoculation of bacterial vaccines 
 and their practical exploitation in the treatment of disease. British Medical 
 Journal, May 9, 1903. 
 
 Wright. On some further improvements in the procedures for testing and 
 judging by the naked eye of the agglutinating and bacteriolytic effects exerted 
 by the sera of patients suffering from, or preventively inoculated against, 
 typhoid fever, Malta fever, and tuberculous affections. Lancet, July 25, 1903. 
 
 Wright. On the protective effect achieved by anti-typhoid inoculation as 
 exhibited in two new statistical nports.ffritisA Medical Journal, October 
 10, 1903. 
 
 G
 
 76 ANTI-TYPHOID INOCULATION. 
 
 Wright and Douglas. An experimental investigation of the role of the 
 blood-fluids in connection with phagocytosis. Pro c. Royal Society, Vol. 72, 
 1903. 
 
 Wright. On certain new methods of blood examination with some indica- 
 tions of their clinical importance. Lancet, January 21, 1904. 
 
 Wright. On anti-typhoid inoculation. 1'ractitioner, January, February, 
 and March, 1904. 
 
 (The present volume consists of a reprint of these papers.} 
 
 Wright and Douglas. Further observations on the role of the blood fluids 
 in connection with phagocytosis. Proc. Royal Society, Vol. 73, 1904. 
 
 Wright. On the treatment of acne, furunculosis, and sycosis by the thera- 
 peutic inoculation of a stapylococcus vaccine. British Medical Journal, 
 May 7, 1904. 

 
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