KEVIEWS. 
CONTAGION EXPLAINED.* 
O F all the great questions which medical science has from time to time 
laboured to answer, there is none at once so entangled or so desirable of 
solution as that of contagion. The reason why the diseases included in the 
class ^‘zymotic” spread from one human being to another, till at last a whole 
community is plague-stricken, is one in which every one finds an interest, 
some from selfish, some from philosophic motives. It behoves us, therefore, 
to consider with discrimination unmixed with passion, every effort which is 
made to explain this problem, which the whole world attempts to solve. 
The task of judgment is, too, all the more pleasing and less difficult, because 
of the number of side-lights, as it were, which fall upon the subject from 
the discoveries of scientific workers who have laboured in the vast fields of 
Chemistry, Physiology, and Hygiene. It is, therefore, with a full sense of 
what we owe to our readers, that we take up for analysis the last argument 
advanced in explanation of the extension of diseases by contact. 
Dr. James Morris, having buckled on what he regards as a sort of 
syllogistic armour, attempts to apply Dr. Lionel Beale’s law of the develop- 
ment of animal tissues to the ordinary doctrine of contagion, and thus to 
I afford a rational explanation of the spread of epidemic disease — at least so 
! we interpret his observations in the volume now upon our table. And, if we 
be correct in our estimation of the author’s aim, we must say that Dr. Morris 
I has occupied a considerable amount of space in telling us what he might 
' have condensed into two or three pages. We would further remark, that he 
has laid down no principle which has not already been before the profession 
‘ in various forms, and that he is certainly adopting a mischievous doctrinal 
; method in basing an explanation upon an hypothesis which must even now be 
regarded as suh-judice. Briefly, the pith of Dr. Morris’s teaching is this : All 
i epidemic or contagious diseases are propagated by contact of a poison — which 
I is assumed to possess vital powers — with the healthy tissues. This poison, 
like the molecules of nuclear matter, accumulates, and ultimately, under 
j favourable conditions, gives rise to a sort of cell, which is composed of 
nucleus and primordial utricle — of germinal and foianed matter — and which 
i soon throws off small particles, which in their turn become similar cells, and 
I thus spread through the infected organism. This is a definite proposition, 
■ containing, as Dr. Johnson said, a good deal that is true and a good deal 
I that is new ; but the new is certainly not true, and the true is by no means 
new. That in certain cases of contagious disease, the abnormal features 
* ‘‘ Germinal Matter and the Contact Theory.” By James Morris, M.D., 
Bond. Second edition. London : Churchill. 1867. 
