on Milk and Milh-Products. 
387 
however does not proceed so far as in the case of the bacillus of 
butvric fermentation. The dissolution of the casein is in both 
cases due to peptonization. The liquid which is formed betw een 
the cream laver and the undissolved casein is of a yellowish 
colour and slightly alkaline, but neither ropy nor slimy. The 
cream layer, however, is ropy, and the lumps of coagulated 
casein at the bottom of the liquid are enclosed by a slimy mass 
containing ffreat numbers of the bacillus. In this case then it 
is not the milk-sugar, but the albuminous matter in the milk 
which is undergoing slimy fermentation, and the question may 
be asked whether the two distinct kinds of slimy fermentation 
occur in practice. Hitherto thev have not been kept separate, 
and this is not surprising, as the phenomena have been but very 
little studied. In future it might be advisable to pav more 
attention to the subject, and this the more as we may suspect a 
close connection between the one kind of fermentation described 
and the bacillus growing on potatoes. Such hints are worthy of 
being kept in mind should opportunity arise for a remedy 
against what must be described as a serious disturbance of 
practical dairying. 
Those observers who believe that slimy and ropy milk is a 
consequence of certain kinds of food, and who have found that 
with a change of diet the disturbance has disappeared, have been 
thereby the more convinced of the soundness of their opinion. 
But they seem to have entirelv lost sight of the fact that a 
certain kind of feeding stuff mav exercise an unfavourable 
influence on milk in a much more direct way than through the 
organs of the cow. \^ hen ensilage was first introduced as an 
article of diet for milch cows, the crv was raised from a great 
many quarters that it imparted its flavour to the milk and the 
butter. At the present time, it is well known that the milk of 
silage-fed cows is not tainted in anv way, if only proper pre- 
cautions be taken to have the cows milked by people who have 
not handled the silage a short time previous, and not to allow the 
milk to remain exposed to air which is tainted with the smell 
of silage. In like manner it can be imagined that a certain 
kind of food mav be infested with micro-organisms, which, 
getting diffused in the air of the cowsheds, enter the milk and 
set up in it a certain kind of fermentation. If the food in 
question be removed, the ferment is also banished, and the 
complaint no longer exists. 
Blue Milk. — What has been said about the opinions which 
used to be entertained as to slimv and ropv milk might almost be 
repeated word lor word with regard to the phenomenon of blue 
milk. There is, perhaps, this one difference, that in the latter case 
more than in the former a greater number of practical observers 
VOL. XXIU. — S. S. 2 I> 
