482 



NATURE 



\Oct. 4, 1877 



from which I found that the organic poisons retain 

 their activity up to a given point of solution, and beyond 

 that the water renders them inert. Through their extreme 

 capacity for becoming watery, they lose their activity 

 altogether. 



(/) That the poisons are transferable also by the vapour 

 of water, and in this way may escape from the living body. 

 So long as a person is affected with these poisons, and is 

 giving off vapour at a certain temperature, he is poisonous. 

 The poison is distributed by the vapour, and the vapour 

 is diffused in what 1 might almost call invisible spray. 

 The poisons are mechanically carried with the vapour, and 

 the vapour from the affected person may be absorbed by 

 the healthy person. But as soon as the body is dead, the 

 vaporisation having ceased, or a reverse process having 

 been set up, — that is to say, there being a condensation of 

 vapour as theresometimes isonthedead body, — the poisons 

 are no longer infectious in the ordinary sense of the word. 



(y) That the poisons are harmless in their dry slate, 

 but commence to resume their activity in water. In 

 order to ensure their continuous action, they need 

 certain temperatures — certain degrees of heat ; that in 

 this respect one poison often differs materially from 

 another ; and that this marks out on the surface of the earth 

 a specific range for some poisons. For instance, the 

 poison of typhus fever is probably volatile, and condenses 

 with difficulty, with the lesult that it only lives at a given 

 low temperature, and that at a certain degree north of 

 the equatorial line, the disease ceases. There are other 

 poisons which require a greater degree of heat for their 

 distribution, of which the poison of yellow fever is an 

 example. If yellow fever be brought from a hot country 

 to one of our northern ports, it will not live. It may linger 

 for a few days, but as a rule, it will not extend. 



(k) That the poisons are all capable of being destroyed 

 by various means. They are all destroyed, as already said, 

 by extreme dilution. They are all destroyed also by heat 

 and by oxidising agents. The mere exposure of them to 

 moist oxygen destroys them rapidly. The exposure of 

 them to ozonised, or electric oxygen, destroys them even 

 more rapidly than ordinary moist oxygen. Exposure of 

 them to chlorine is instantaneous destruction to them. 

 Exposure to iodine is nearly as effective, and if the 

 iodine can be diffused equally, it is as destructive as 

 chlorine. Exposure to bromine leads to the same result. 

 Exposure to nitrous acid has the same kind of effect, but 

 not in so marked a degree. Exposure to sulphurous acid 

 likewise produces destruction. 



(/) That snake poison is destroyed by sunlight, and 

 that the destruction does not depend upon the temperature . 

 That bright sunlight is probably one of the means for 

 destroying the organic poisons. 



(;//) That almost all the organic poisons are preservable 

 by cold, and that, in fact, there is no limit to the preser- 

 vation of them by extreme cold. The poisons are 

 preserved also by many antiseptics. Sulphur, creasote, 

 and arsenic, hold these organic poisons in preservation, 

 so that they preserve their active properties. 



(«) That some of the poisons are only poisonous during 

 certain stages of their decomposition ; with regard to 

 the disease called hospital-fever, there is perhaps only one 

 certain stage when the secretions really contain the 

 poison. There is a certain given stage in the process of 

 the manufacture of the poisons when the secretions 

 change, and at that point the poisonous matter becomes 

 innocuous. 



((?) That in considering the development of these poisons 

 it is a common error to suppose that they multiply from 

 a germ as offspring multiply from parents, but that what 

 occurs is this : — Each particle of any one of these poisons 

 brought into contact either with the blood of the living 

 animal or with certain secretions of the living animal, 

 possesses the property of turning the albuminous part of 

 that same blood or that same secretion into substance like 



itself. The process of change is catalytic. It is a change 

 by which a body is transformed by the presence of some 

 other body which does not itself undergo change. The 

 multiplication of the poison thus takes place through the 

 force of secretion of the person alfected, not through the 

 propagation of germ from germ. For instance if poison 

 producing contagious ophthalmia be passed from the eje 

 of one person into the eye of another, presently there is a 

 free secretion. The secretion soon is profuse and is 

 affected by catalysis from the poison. If the inoculation has 

 been deep the whole animal will be affected ; if it has not 

 been deep only the eye will at first be affected. It is not that 

 the particle of poison has propagated a new panicle, but 

 it is that the natural secretion of the eyeball has come in 

 contact with a speck of poisonous matter, and imme- 

 diately at that point where the speck of poison was there 

 is a change in the secretion. This process widens the 

 circle, more secretion pours out and more poison is pro- 

 duced, and the increase goes on until in the end the whole 

 body of the animal may become affected by absorption 

 into the body from the injured surface of poisonous matter : 

 ultimately, i.e., the poison is absorbed into the blood. 



(/) That as a general rule the human body furnishes 

 all the poisons that the human body suffers from, that is 

 to say, there is a progression of poison from one body to 

 another, and that ordinary secretions may change and 

 become poisonous without previous infection. This, I 

 showed, had been remarkably brought out in the case of 

 puerperal poison, where a secretion irom the hind of the 

 accoucheur had produced puerperal fever. In the case of 

 peritonitis, or inflainmation of the peritoneum, there is a 

 secretion which may be carried on the hand of a healthy 

 person and reproduce the disease. Typhus may be pro- 

 duced by the overcrowding of persons in a room through 

 the vaporisation of organic matter at alow temperature. 

 Thus we may have springing up de novo an organic poison 

 which afterwards, on being mtroduced into one particular 

 body, becomes increased by the secretions of that body. 



{q) That as regards the mode in which the organic 

 poisons may be transmitted, they may travel in each of 

 three ways. They may travel by means of sewage as dry 

 solid matter; and all the poisons do this constantly. 

 They may be wafted in the air, or carried by means of 

 linen saturated with the secretions of patients and dried. 

 Again, they may travel in water or in water suspended in 

 the form of vapour. 



(;•) That the mode of the entrance of organic poison into 

 the body, when they enter by contact, varies with the 

 different poisons, the character of the poison changing 

 the mode of its introduction. The poisons of measles, 

 scarlet fever, and typhus are inhaled. The poisons of 

 small-pox, diphtheria, glanders, erjsipelas, hospital-fever, 

 and ophthalmia, require direct contact. The poisons of 

 cholera, 5 ellow fever, and typhoid fever seem always to 

 be swallowed poisons, and may be called, spec fically, the 

 poisons of sewage, and therefore mostly travel in a fluid 

 form. They may, nevertheless, travel for short distances 

 as fine dust, and they may travel in water in the form of 

 vapour. 



The thought that the poisons of the various spread- 

 ing diseases are poisonous secretions, and nothing more, 

 came naturally out of my researches. I realised, as it 

 seemed to me, that all these spreading and commu- 

 nicable diseases spring out of the living animal body. 

 That they are as distmctly the offspring of living ani- 

 mals as real progeny are, and that to look 10 outside 

 sources for them, to look to vegetative growth for them, 

 for example, or seedling, is merely to ignore the basic 

 facts which lie obviously before us for lesson and learning. 

 As well suppose that procreation of animals is due to an 

 external vegetable product or other product dissevered 

 altogether in its origin from the animal as that the poison 

 which creates disease of a communicable kind is in such 

 manner dissevered as to its origin. 



