1895 - 96 .] Mr D. F. Harris on Chemistry of Milk. 
83 
ditions were the same, except that, instead of the potassium salt, an 
equal volume of water was added to the milk. 
The tubes containing the following salts yielded clots in as short 
a time (usually 10 to 15 minutes) as the clot took to appear in the 
control tube : — 
Potassium acetate (alkaline). 
>> 
sulphate ,, 
5) 
chlorate ,, 
>> 
nitrite ,, 
5 J 
ferrocyanide „ 
J> 
nitrate (neutral). 
J) 
chloride ,, 
J) 
bromide ,, 
>> 
iodide „ 
phosphate (acid). 
In the tubes containing the following salts no clots were obtained 
at the end of 30', and not until the alkalinity had been reduced 
or neutralised or the reaction made faintly acid by acetic acid : — 
Potassium, bicarbonate, bichromate, carbonate, chromate, cyanide, 
ferricyanide, permanganate, — these salts, except the second, are 
alkaline, some very decidedly so. 
No clot was obtained when potassium oxalate was added to the 
milk, — the examination of this result will be taken up under 
decalcified milk. In no case was a salt of calcium added to the 
tubes, so that where a clot did occur it was in presence of a pre- 
ponderating amount of potassium compared with calcium salt. 
Thus, the group of potassium salts is sharply divided into two 
groups — (1) those faintly alkaline, neutral, or acid salts which do 
not antagonise the clotting of procasein in milk ; and (2) a smaller 
group, all alkaline, which either inhibit the fall of casein, i.e., delay 
its appearance beyond the normal time for clotting, or antagonise it 
altogether. 
This inhibition or antagonism would seem to depend more upon 
the reaction of the potassium salt than upon any property in the 
salt as a salt of potassium. 
It was not necessary in these experiments to apply Ringer’s test 
as to whether procasein had been formed, because he holds that 
