December 9, 1887.] 



SCIENCE. 



279 



It was another wonderful fact when scurvy yielded to the pre- 

 "ventive art. The great naval hospital at Haslar, England, had 

 been built with special reference to the fearful inroads that this dis- 

 ease was making amid the British fleets. When, in 1796, Sir Gil- 

 bert Blane and other medical officers of the navy obtained the order 

 that lime-juice be supplied to the seamen, the terror of that disease 

 was taken away. Studying the facts by the history and peculiar- 

 ities of that disease, we cannot dismiss it as a mere error of diet- 

 ■etics. It was not simply that fruits and fresh vegetables prevented 

 the disease. It was a far-reaching lesson as to how diseases may 

 be modified by medicines as well as by foods ; how the presence of 

 something administered may prevent a disease. > 



As to the next wonder of the preventive art, that of Jennerian 

 vaccination, it is so often presented as to need only our passing rec- 

 ognition. Yet it is to be remembered that it is a subject not yet 

 exhausted. Whether something of the modification is owing to 

 the mode and place of introduction, whether it is a modified small- 

 pox, whether it is attenuated virus and may be in different degrees 

 of attenuation, and so differently protective, these and other ques- 

 tions are left over to be determined in this period when the micro- 

 scope, the pathological, the chemical, and the biological labora- 

 tories have come to the aid of the clinician, and we can study and 

 ■compare the accumulated facts. 



The Pasteurian vaccination may stand next, if not in order of 

 time, since Pasteur opened his Copenhagen address by profound 

 •acknowledgment of his indebtedness to Jenner as the great fore- 

 father of preventive medicine. 



Here the mode and place of introduction, degree and permanency 

 •of effect, and the nature and cause of the so-called attenuation, are 

 still before us with unanswered inquiry. 



Next, while the doctrine of the prevention by isolation is old, yet 

 new methods and new results, as to it, almost make it a new pre- 

 ventive art. Sea and land quarantines are modified, and ought to 

 be. How far it is to be isolation of the person, or only isolation of 

 the personal effects, is unsettled. What the forsaking of an in- 

 fected house or ship will do, what the camping-out of all the well 

 from a sick city will do, what isolation alone will do, as in Lei- 

 cester, with small-pox, and what is the most perfect plan of organ- 

 ized systematized isolation, — all these are before every health- 

 officer as large and most practical questions. 



Next comes disinfection, in all it means by the new light of biol- 

 ogy and the study of micro-organisms — whether it be the de- 

 struction of animal or vegetative parasitic life — oftheseaslarvse, as 

 spores, or as sporeless plants, at any and all stages of existence and 

 development ; also what is meant by inhibiting or thwarting action, 

 even when we do not destroy life ; also what disinfectants can do 

 with the surroundings in destroying the pabulum or nutrient media; 

 also what these can do in the system, either to destroy the microbe 

 which is setting up pernicious activity there, or in some way to de- 

 prive it of its food or limit its power. 



For the present we confine ourselves to the last item. So soon 

 as it became certain that many diseases depend upon, or are asso- 

 •ciated with, micro-organisms, the inquiry was in order, whether 

 •there could not be some method utilized and applied by which the 

 presence or activity of these in the blood-tissues or secretions could 

 be so interfered with as to prevent or mollify disease. Passing for 

 the present certain facts as to septic and non-pathogenic organisms, 

 which, introduced into the system, may of themselves, or by their 

 ferments or alkaloids (ptomaines), cause disease, we confine our in- 

 quiry to the question whether it is possible to thwart the action of 

 the specific or pathogenic micro-organisms in their attempt to in- 

 vade or after they have invaded the system. We get some light or 

 ■some analogy as to this from considering the Ufe-history and be- 

 havior of these organisms outside the system. First of all, we find 

 that pathogenic organisms are dependent for their growth on the 

 presence of the suitable nourishing material. In this respect they 

 are far more selective than the septic organisms, which " find in 

 almost all animal and vegetable fluids the substances necessary 

 for nutrition." It is further found that there are substances which 

 inhibit the growth of, or altogether destroy, these micro-organisms, 

 such as corrosive sublimate, salicylic acid, etc. To do this they 

 .do not always need to be germicides. 



Far short of destruction, such substances are capable of restrain- 



ing the morbid action so far as to thwart their pernicious activity, 

 which, in the case of an invading disease, is really the gravity of 

 the disease. 



Klein gives abundant evidences and references, on p. 208 of his 

 book on ' iVIicro-organisms and Disease,' to show that " pathogenic 

 micro-organisms are capable of suffering some modifications in 

 their morphological and physiological behavior." He adds, "Now, 

 it is known of many micro-organisms, bound up with infectious 

 diseases, that temperature, the medium in which they grow, and 

 the presence or absence of certain chemical compounds, are capable 

 of materially affecting them" (Klein, p. 207). 



Inasmuch as this growth and multiplication are known to go on 

 in the bodies of living animals, and to constitute the identity and 

 gravity of many diseases, it is a radical and very essential and hope- 

 ful inquiry whether we may not, by some change in the animal, or 

 in some of those chemical compounds referred to, either destroy the 

 micro-organism or inhibit its activity. 



It is very suggestive of the possibility of this to remind ourselves 

 of the probable reason why some are unsusceptible to disease. Dr. 

 Klein (p. 247) argues that it is because there is " something or 

 other present in a particular tissue to which the latter owes its im- 

 munity." 



He infers, that, although this is " dependent upon the life of the 

 tissue, it is not identical with any of the characters constituting its 

 life." He says, " The most feasible theory seems to me to be this, 

 that the inhibiting power is due to the presence of a chemical sub- 

 stance produced by the living tissues." This puts the body in such 

 a condition that in the particular case, " the organisms cannot 

 thrive and produce the disease." It is true that he suggests that 

 the germicide or inhibitive material is a product of living tissue. 

 This is not necessarily so, or, if so, would not necessarily be a prod- 

 uct of the living tissue of the human body. 



If the non-activity of the organism, and so the non-occurrence of 

 the disease, is owing to " the presence of a chemical substance " 

 in the tissues or blood, it is a very pertinent and natural inquiry 

 whether we can not and do not produce the same result by putting, 

 and for a time sustaining in the system, certain " chemical sub- 

 stances," which, so introduced, interfere with the processes sought 

 to be set up, and which would constitute the disease. 



The analogy is strengthened by the fact that chemical products 

 are so much coming to be suspected or recognized as constituting 

 the virus or specificity of diseases in which the micro-organisms 

 are the initiative factors. 



Still more, however, it behooves us to find out whether, either in 

 chemical or laboratory experience, there has been any confirmation 

 of such views. In clinical experience we have long had not only 

 the fact that quinine will cure chills and fever, but that it is a sub- 

 stance which, introduced into the human system in advance, will 

 prevent those processes which constitute the disease. So soon as 

 it was made probable that the malarial diseases belong to the 

 species or genera of microphytic diseases, so soon it seemed 

 probable that the result was due to this inhibitive effect of the al- 

 kaloid. As a result of experiences with epidemics of diphtheria 

 and scarlet-fever, so long ago as at our Chicago meeting in 1877 

 (see Americaji Public Health Association, vol. iv. p. 348), I pre- 

 sented a paper on this mode of assisting and preventing pestilential 

 diseases (see also two articles on the subject in The Medical Rec- 

 ord, vol. ii. 1877). 



The next year the subject was more fully presented in a paper 

 read at the Richmond meeting. 



In the intervening time Professor Cabell was so impressed by 

 the facts presented, as to note it in his address before the Ameri- 

 can Medical Association in the spring of 1878. A reference to the 

 paper of 1 878 will show how fully this idea was insisted upon and 

 illustrated. It was claimed that by the use of certain medicines 

 we could prevent the sedation or interrupt the development of that 

 which constituted the infection. Many of the facts in support of 

 this view at that time were collated, and since then, from time to 

 time, medical men have corroborated these views from their own 

 experience. 



It is of value that since then we have come into a knowledge of 

 several other diseases as microphytic, and this has greatly fortified 

 the position then taken. 



