366 
ever, a rapid alcoholic and lactic fermentation takes place. Accord- 
ing to this author also the ferment of the grains consists of the Bacillus 
dispora Caucasica (Kern) and a modified form of the ordinary yeast, 
Saccharomyces cerevisix. According to von Freudenreich (34) the 
grains contain at least two species of bacteria and one species of 
veast, which acting together produce the kefir fermentation. The 
bacteria effect the inversion of the milk sugar, after which a portion 
of the simpler sugar is converted into alcohol by the action of the 
yeast and another portion into lactic acid by the further action of* the 
bacteria. The milk is curdled during" this fermentation. 
According to Martinand (35) milk imdergoes alcoholic ‘fermentation 
with a great many species of yeasts, especially if glucose and malt- 
ose be added, and coagulation of the milk occurs under these 
conditions even in the absence of acids. 
PART II (4b) MILK POISONING— GALACTOTOXISMUS. 
Of all foods milk is probably the most subject to contamination 
and change. Of the various forms of contamination to which it is 
liable the commonest is, as we have already seen, that which results 
from the introduction into the milk of lactic-acid-producing bac- 
teria from various sources. These organisms accomplish those 
changes which are familiar to us in the ordinary souring of milk. 
While according to Stoakley (1) buttermilk is sometimes responsi- 
ble for acute milk poisoning, it is the general opinion that sour 
milk but rarely gives rise to troubles of this character. Indeed, by 
a number of medical authorities sour milk is regarded as a very 
healthful beverage, by reason of the fact that the lactic-acid-pro- 
ducing bacteria tend by their growth in the intestine to lessen intes- 
tinal putrefaction, thereby diminishing the tendency to auto-in- 
toxications from substances resulting from the growth of the bac- 
terial flora normally present in the intestine. On the other hand 
is not infrequently happens that fresh milk becomes contaminated 
with toxic substances, or with toxicogenic bacteria, in which event 
the milk may give rise to acute intoxications. The subject of milk 
poisoning' has been chiefly studied by Vaughan and his associates, 
and to him we owe the term Galaetotoxismus. In spite of all that 
has been done however the subject of milk poisoning is as yet but 
very imperfectly understood. Chiefly through the labors of Vaughan 
(2) and his coworkers, together with observations by Sonnenberger 
(3) , Le Blanc (4), Baird (5), and others, it is now known that milk 
may acquire poisonous properties and become dangerous to health 
in essentially five distinct ways : 
First. It may absorb metallic poisons from metallic vessels in 
which it has been allowed to stand. Attention has already been 
