377 
pure culture. The investigation of the peptonizing bacteria of milk 
has been continued by Luebbert. and also by Vaughan. According 
to Luebbert (21), these organisms are widely distributed. They 
have been found to act only on the proteids of the milk, the fat and 
milk sugar contained in the milk remaining undiminished. He also 
j found the milk cultures of these organisms to be highly toxic. When 
fed on such milk, guinea pigs died after four days, and puppies after 
the fourth, fifth, and sixth day, following severe diarrheas. On the 
other hand, a full-grown dog ate of the milk freely without any bad 
effect, thus showing that age affords some protection against milk 
poisoning. Luebbert’s results on the toxicogenic peptonizing bac- 
teria of milk have been confirmed by Vaughan (22). According to 
this author the organisms responsible for cholera infantum are truly 
pathogenic in that they produce a definite chemical poison, the ab- 
sorption of which is followed by the symptoms of the disease, and 
in order to explain the great susceptibility of infants to milk poison- 
ing and the comparative immunity of the adult he has advanced the 
view that the great susceptibility of children to such intoxications 
is due to the ease and readiness with which casein is absorbed by 
the mucous membrane of the intestine of children, and that the 
casein carries along with it the bacterial cells containing this poison. 
In the adult, on the other hand, the digestive powers of the stomach 
are increased and intestinal absorption modified to a corresponding 
degree. At present practically nothing is known regarding the pre- 
cise chemical nature of these bacterial poisons, and, as already pointed 
out by Novy (19) , investigations pertaining to a more exact study of 
the toxicogenic micro-organisms of milk and their poisonous products 
belong to the future of medical and chemical research. I have been 
informed by Doctor Vaughan that nothing of any practical impor- 
tance has been added to our knowledge of the milk poisons during 
the last few years. 
PART III.— CHEMICAL STANDARDS EOR THE CONTROL OF THE 
SALE OF MILK. 
For a number of years the sale of milk in various cities throughout 
the world has been regulated by law and various chemical standards 
regulating the sale of milk have been proposed, based on the results 
of large numbers of analyses of milk in various countries. I am 
indebted to L. A. Eogers, Acting Chief of the Dairy Division, Bureau 
of Animal Industry, U. S. Department of Agriculture, for the fol- 
lowing compilation of United States and State standards for milk 
and dairy products. It will be observed that this compilation was 
published in 1905. 
