521 
methods recommended by different investigators are not directly com- 
parable, it is nevertheless evident that an entire lack of harmony 
exists at present among them which makes the reliability of one or 
more of the methods at least doubtful. The Doane-Bucldey and 
Trommsdorff methods are probably the most preferable, but neither 
of these is perfect and should not be depended on per se for the deter- 
mination of udder inflammations by the examination of market milk 
or even the mixed milk of a herd. 
Eecently Eussell and Hoffmann ® have presented an improvement in 
the technique for determination of the leucocyte content of milk. 
Their experiments show that many leucocytes are not recovered in the 
sediment after centrifugalization by the usual methods, and that it is 
necessary to heat the milk to a point where the creaming power is so 
greatly diminished as to alter the physical arrangement of the fat 
globules. In this manner practically all the leucocytes which were 
enmeshed are liberated and thus enabled to be thrown down and 
recovered in the sediment. These observers used the Doane-Buckley 
quantitative method with milk which had been heated momentarily 
at 70° C. and obtained a count which was in some cases as much as 
four times greater than that secured from the same lot of milk un- 
heated. This increase is usually so marked that it is far beyond the 
limits of analytical error, and, furthermore, such error is reduced to a 
minimum by this method of determination. These experiments have 
opened up an interesting line of investigation, and the limits of lactic 
leucocytosis, which have been adopted by some States, based upon the 
old standards, must be modified accordingly. Since it has been found 
that the heating of milk is absolutely essential in obtaining a some- 
what definite idea of the number of leucocytes in milk, and inasmuch 
as this improvement in the technique, which is as necessary as any 
other part of the process, results in a much higher count than has 
heretofore been observed in any of the previously described methods, 
it is evident that there must be a higher leucocyte standard applied 
for judging milk than has obtained in the past. Milk inspection may 
be greatly benefited by the establishment of some rational standard 
for the leucocyte content of milk, but more study must be given to this 
subject in order to obtain the desired knowledge. 
GASTRO-ENTERITIS. 
The milk of cows affected with gastro-enteritis is of an abnormal 
character, being watery, of bitter taste, and changes quickly to a 
“ sweet curdle.” This milk is liable to produce digestive disturbances 
in the consumer and should not be utilized. 
“American Journal of Public Hygiene, p. 285, August, 1908. 
