20 Belation of Microsco;pic Fungi to {^f^^lXM^^^^TS} 
described, what is more likely than that a small quantity of choleraic 
matter should get attached to the hands, and be introduced with the 
food into the mouth? 
Now it is found that if the ordinary rules of hygiene are 
observed, there is an absolute immunity from infection among those 
who are with the cholera patients and come into the closest contact 
with them. They may rub and wash them, attend to them, dissect 
their bodies, or analyze them chemically as we have done, without 
the least evil consequences. During the epidemic of 1866, wherever 
special modes were employed to avoid those ordinary known and 
supposed means of introduction, we did not observe one instance 
in which the active cholera poison was actually introduced into a 
person so employed. 
Every kind of rashness and excess predisposes persons to cholera. 
No doubt poverty and bad living, engendering as they do dirt, 
irregular hours, and excess, are important aids in the production of 
the chemical process of which we shall have to speak. 
I put it down then as a thesis to be derived from what I have 
laid before you, and one which I do not think will be controverted 
in the present state of affairs, that the infectious matter hy which 
cholera jprojpagates is the fermented cholera excrement. 
" Eice- water " stool is a term which owes its origin to the simi- 
larity of the evacuation to a decoction of rice. It is a very white 
fluid, almost milky in some cases, and there is suspended in it a 
greyish-white flocculent matter, like the peculiar starch of rice 
which is detached from it by boiling. If you take this rice-water 
and test its reaction, you find it strongly alkaline. It has not a 
very great fecal odour, but sometimes a remarkably putrescent 
smell ; and immediately it is out of the body it continues the pro- 
cess of decomposition to which it had before been subject. Kice- 
water contains a derivate of the substance which we call mucine, 
the basis of mucus. Mucine is distinguished by its being precipi- 
tated by acetic acid, by its being dissolved in alkalies, and swollen 
up to those masses which you know as the means by which the 
human body lubricates all the surfaces of its cavities and exits. 
Amongst various interesting other properties is this, that on decom- 
position with hydrochloric acid it yields sugar. Other derivates 
contained in the rice-water are those of albumen, besides albumen 
itself. You know that in certain decomposition processes albu- 
men yields butyric and acetic acid. Those acids are found in the 
cholera-stool shortly after its expulsion. 
We further find dissolved in the cholera-stool a small quantity 
of decomposed blood, altered in such a manner that its spectrum 
differs from that of ordinary hemato-crystalline ; the absorption- 
bands are very similar, but the alpha band of the cholera-stool is 
rather narrower than the analogous band of the blood, and the 
