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NOTES AND MEMORANDA. 
includes his observations on the germ theory of disease. The author 
considers that “ by his experiments, in addition to the disproof of a 
false hypothesis, he has unquestionably done one or other of two 
things : either (a) he has proved that living matter may be now 
evolved de novo, or (6) he has succeeded in bringing back to life 
germs which hitherto were so powerless and latent as to have been 
regarded by other experimenters as hopelessly dead. Even the latter 
is no mean result for the physician and the science of medicine, since 
the question of the truth or the reverse of the ‘ germ theory of disease’ 
is thereby almost as powerfully influenced as if the former alternative 
had been established with complete certainty. . . . 
Though it may be conceded that with our present state of know- 
ledge an affirmative decision in regard to the absolute proof of the 
present occurrence of Archebiosis may be still withheld, there is no 
similar warrant for suspense of judgment in regard to the germ 
theory of disease, or, as it is also called, the doctrine of contagium vivum. 
Existing evidence is abundantly sufficient for the rejection of this 
doctrine as untrue ; and from the evidence, more or less fully referred 
to in the paper, it seems to him legitimate to conclude : — 
First, that if we are to be guided by the analogy now dwelt upon 
as existing between fermentation and zymosis, it would be perfectly 
certain that the latter process can originate de novo, that is, under the 
influence of certain general or special conditions, and where specific 
contagia of any kind are at first absent, though they subsequently 
appear as results or concomitant products. So that an exclusive 
theory of ‘ contagion,’ as the only present cause of communicable 
diseases, is not supported by experimental evidence. 
Secondly, that some contagia are mere not-living chemical prin- 
ciples, though others may be living units. 
Thirdly, that even in the latter case, if the primary contagious 
action be really due to the living units, and not to the media in which 
they are found, such primary action is probably dependent rather 
upon the chemical changes or ‘ contact actions’ which they are 
capable of setting up, than upon their mere growth and vegetative 
multiplication. 
Fourthly, that where we have to do with a true living contagium 
(whether pus-corpuscle or ferment organism), the primary changes 
which it incites are probably of a nature to engender (either in the 
fluids or from the tissue-elements of the part) bodies similar to itself, 
so that the infected part speedily swarms therewith. When pus from 
a certain focus of inflammation comes into contact with a healthy 
conjunctiva, and therein excites a contagious form of inflammation, 
no one adopts the absurd notion that all the pus-corpuscles in this 
second inflammatory focus are the lineal descendants of those which 
acted as the contagium ; and the mode of action may be altogether 
similar when the matter containing Bacilli, by coming into contact 
with a wounded surface, gives rise to splenic fever and the appearance 
of such organisms all through the body. The old notion about the 
excessive self-multiplication of the original contagium is probably 
altogether erroneous. Thus all the distinctive positions of those who 
