RESULTS OF EXPERIMENTS ON PYAEMIA. 421 
“ spontaneous generation” were observed, pyaemic pus could 
not be so kept, and, moreover, possessed the properties of at 
once determining the development of bacteria in any suitable 
liquid to which it was added. At that time he had concluded, 
as he now knew, from insufficient observation, that pyaemic 
pus did not itself contain visible bacteria. 
A short account was next given of certain researches made 
during last summer, in association with Dr. Klein, as to 
channels by which infective poisons were distributed from 
their centres of origin. Referring to the last occasion on 
which he had brought the subject of the intimate pathology 
of tubercle before the Society, and to the doctrine he had then 
advocated, that tuberculosis is an irritative overgrowth of a 
pre-existing tissue, he said it had then been shown that the 
process, in its disseminated or interstitial form, had its seat 
in a certain tissue, and this tissue had been termed adenoid 
or lymphatic—both words implying its intimate and special 
relation with the lymphatic system; but the precise anato¬ 
mical nature of this relation had been imperfectly made out. 
No further progress was made till last May, when Dr. Klein 
came to England with the distinct object before him of co¬ 
operating in the investigation of this very question. The 
field taken up was the peritoneum; the reason of the choice 
being, that that membrane, and especially the omentum and 
diaphragm, had already been the subject of investigation, as 
favourite seats of tuberculosis. Those researches had not 
merely served to elucidate one or two anatomical facts of very 
great importance to the pathologist— e.g. the existence of a 
lymphatic system in the omentum and its distribution, and 
the mode in which the peritoneum communicates with the 
lymphatic system—but had rendered it possible to give an 
account which, so far as the peritoneum was concerned, was 
tolerably exact and complete, both of the normal process of 
absorption and of the changes which the absorbing tissues 
undergo when they are entered by infective agents. 
In the course of these experiments it was found that not 
only as regarded the property of any given peritonitis to 
assume the infective character, but as regarded the intensity 
of the infective results and their duration, there were endless 
varieties. In one set of cases, the secondary lesions were 
suppurative, the constitutional disturbance intense, and the 
fatal result rapid; in another, the lesions were vascular new 
growths, firm at first, afterwards becoming caseous, the pro¬ 
gress slow, and the functional disturbance imperceptible. And 
then it appeared that in all those instances in which the 
pyaemia —L e. the acute character—manifested itself, bacteria 
