34                       STATISTICAL RETURNS OF THE LUNATIC ASYLUMS.

his strains, and will publish his complete results at a future date. MacConkey's
bile salt lactose agar was the medium employed.

Before coming to the figures, it may be well to state that it was found quite
impossible to isolate dysentery bacilli from feculent stools. Such bacilli could only
be isolated from mucoid stools, and then the mucus had to be repeatedly washed
in sterile saline solution before plating, so as to remove every trace of feculent
matter, and leave a clean, sometimes bloody mucus. Otherwise, the plate was
swamped by growths of other bacilli. Even after selecting stools and taking
these precautions, positive results were obtained in only 43 instances out of the
86 cases examined—a proportion of 50 per cent., although every case plated was
clinically a case of dysentery. Furthermore, in many of these cases the patient's
stools were plated several times, and a positive result was obtained only after
repeated platings. Success was obtained only when the stools were freshly passed.

These experiences appear to the writer to be of considerable practical import-
ance, regarding the diagnosis of bacillary dysentery. It would appear that the
failure to discover dysentery bacilli in the stools is in itself of little importance in
the diagnosis of the disease, as if the stools are kept for any considerable length
of time before plating, or if anything but well washed mucus free from fæcal
matter is plated, a negative result may be expected. Consequently, it seems
logical to conclude that the practice of sending unplated stools by post, in a sealed
vessel, to a laboratory for bacteriological examination, in the hope of isolating
the bacilli of dysentery, is only waste of time, and that any inferences drawn
from negative results in such cases, are quite valueless.

Practically, the diagnosis between the amœbic and non-amoebic forms has to
be made from—

(a) The presence in, or absence from, the freshly passed mucoid stools, of
amoeba hystolitica. (b) The isolation by bacteriological methods of the specific
micro-organisms from the stools, bearing in mind that (a) a negative result is of
little value, and (b) that a mixed infection is, of course, possible.

There is one clinical observation which seems to be of value, namely, that
acute cases, with fever lasting about three days (although the dysentery may
persist longer) in individuals, who have not previously suffered from dysentery,
are almost certainly bacillary.

In Madras Asylum, one could not help being struck with the fact that of five
undoubtedly amœbic cases, three occurred in Europeans, and the fourth in an
Indian who had lived out of India for many years, and who fell ill with dysentery
three days after his arrival from Singapore.

The success or failure of emetin treatment is of little use from a diagnostic
point of view—except in cases where the ordinary forms of treatment have been
tried and have failed, and where emetin succeeds. In such cases, the conclusion
apart from all other evidence, that the disease is amoebic seems justified. But
the fact that an acute case of dysentery gets well on emetin treatment, plus a
diet of citrated milk or whey, plus (probably) purgation by salines or castor oil,
is no proof at all that emetin has had anything to do with the recovery. As will
be seen from table VI, 20 cases were treated with hypodermic injection of
emetin hydrochloride, and with the exception of the cases in which amoeba
hystolitica had been found microscopically, emetin appears to have had little
influence in the disease one way or the other.

As regards miscroscopic examination, it will be seen from table II, that
amoeba hystolitica was present in five cases. Of these, three were Europeans,
and one was an Indian lately returned from Singapore.

The three cases in which balantidium coli were found rapidly succumbed to
the disease, and the presence of this enormous ciliate would seem to be of the
gravest prognostic significance.

Among the members of the staff who are known to have suffered from
dysentery during the period under review, were two warders, an office clerk, and
the superintendent. The attacks (except in the case of the clerk who had amœbic
dysentery) were slight. One of the warders harboured the Shiga and the Super-
intendent the Flexner type bacillus.