Milk. 
313 
grass from irrigated meadows, mangold-tops, and acid slops, 
obtained by allowing barley-meal, cabbage-leaves, &c., mixed 
with a great deal of water, to pass through the so-called lactic 
acid fermentation, the milk becomes very watery. Such milk, 
though unmixed with water, generally is quite as poor as milk 
which has been purposely so diluted. 
The whole question of milk adulterations and means of de- 
tecting them resolves itself into an inquiry into the characters of 
good, bad, and indifferent milk, and the mode of recognising 
these with precision. As the result of my own experience, 
founded on the examination of many samples of milk, produced 
imder the most varied circumstances, and purposely adulterated 
with known quantities of water, I may state that milk may be 
considered rich, when it contains from 12 to 12|- per cent, of 
solid matters, and from 3 to 3^ per cent, of pure fatty substances. 
If it contains more than 12| per cent, of dry matter, and 4 per 
cent, or more of pure fat, it is of extra rich quality. Such milk 
throws up from 11 to 12 per cent, of cream in bulk, on standing 
for 24 hours at 62' Fahr. 
Good milk of average quality contains from lOj to 11 per cent, 
of dry matter, and about 2|- per cent, of pure fat. It yields 
from 9 to 10 per cent, of cream. Milk adulterated with water, or 
naturally poor, contains more than SO per cent, of water, and less 
than 2 per cent, of pure fat. Such milk yields only 6 to 8 per 
cent, of cream, and even less if it be very poor. 
A comparison of the results obtained in the milk anal^'ses 
embodied in this paper will show that whereas the proportions 
of curd, mUk-sugar, and ash, do not greatly vary in good, bad, or 
indifferent milk, the percentages of butter (pure fat) in different 
samples of milk are subject to considerable variations. In other 
words, the quality of milk depends more on the amount of butter, 
or rather of cream, which it contains, than on that of any other 
constituent. 
An instrument, therefore, by means of which the percentage of 
cream could be determined accurately and readily, would be most 
valuable for the purpose of ascertaining the relative qualities of 
different samples of milk. Creamometers are instruments which 
have been recommended for that purpose. Thev are made either 
in the form of a cylindrical measuring glass, with glass foot, and 
divided into 100 equal degrees, or in the form of graduated wide 
glass tubes. The graduations proceed downwards, from a point 
near the open end, marked zero, and each degree indicates 1 per 
cent, of cream. A number of these tubes are conveniently kept in 
a vertical position by a frame fitting into a cylindrical tin box, 
which, if necessary, may be filled with water of the required 
temperature (62^ Fahr.), and covered with a lid, having an 
