APPENDIX /® 
DETAILED DESCRIPTION OF THE METHOD OF ANALYSES 
EMPLOYED. 
For the benefit of those who may be engaged in actual 
water analysis we consider it advisable to give a brief des- 
cription of the actual details of the method employed in 
this work. All samples for bacteriological purposes are 
taken by a special messenger who has been carefully trained 
in the technique. He is supplied with sterile bottles of 250 c.c. 
capacity. These are carefully wrapped up in brown paper, 
a piece of string is attached to the neck of each (in case the 
bottle is required for taking samples from rivers), and the 
bottle, paper, string and all, are sterilised in the autoclave. The 
messenger is also supplied with sufficient ice to enable him to 
keep the samples cool during transit to the laboratory. This 
is a very necessary precaution. Samples sent by train, packed 
in ice, are subject to so many accidental delays that we find | 
that for bacteriological work in India, at any rate, this method 
of transit is not sufficiently satisfactory to be practicable. 
Travelling is distinctly cheap in India, and the expense 
incidental to collecting the samples is not very great, pro- 
vided a regular programme of work for the year is prepared 
and adhered to. 
On arrival at the laboratory three separate series of 
bacteriological analyses are at once started, the bottles having 
been well shaken. 
These are (1) total colonies count in I c.c. of water, 
and (1) inoculating of tubes of MacConkey’s bile salt broth 
with various quantities of water : (777) 20 c.c. is centrifugalized 
in order to test for streptococci. 
(x) Total colonies in i c.c. A count of the total colonies 
in I c.c. of water is made on agar. The medium used for this 
is very carefully prepared, so as to get each brew of the same 
reaction and strength. Lemco 4 per cent., Witte’s peptone I 
