RopiNESS IN Milk and Cream. 397 



theoretical interest. After a critical reading of Adametz's paper 

 in the Landwirlhschaftliches Jahrbiicher oi 1891, it becomes evident 

 that misconstructions have been placed upon his statements. On 

 page 191 of the volume referred to he makes a statement of 

 which the following is a translation : ''Sterile milk inoculated 

 with Bacillus lactis viscosus and kept at room temperature, shows 

 lit tie outward appearance of change during the first two days 

 But the surface layer of cream is found to be ropy when tested 

 and the increased viscosity of the skim milk below becomes 

 evident when it is stirred." Farther on in this paper he says : 

 " In cultures contained in test tubes where the milk is slightly 

 exposed to the air,* the complete change of all the milk does not 

 occur until about four weeks." Those writers who have under- 

 estimated the practical bearing of Adametz's work, seem to have 

 labored under the impression that ropiness must necessarily 

 appear in the depths of the milk as well as in the cream, in order 

 to be the cause of serious trouble. 



My observations upon the occurrence of ropiness in milk in 

 creameries in New York, and the identification of Bacillus lactis 

 viscosus as the cause, show that the ropiness brought about by 

 that organism although appearing only in the surface layer of 

 milk, may become of considerable commercial importance. 



In the summer of 1898, the appearance of ropy milk in a local- 

 ity near Ithaca was brought to notice by a milk dealer, who, 

 having suffered severely in loss of custom by its occurrence, 

 applied to the College of Agriculture for aid. He was instructed 

 to dampen the udders of the cows with dilute carbolic acid before 

 each milking. This measure, which is of value in preventing 

 filth on the udder from falling into the milk, was carried out 

 faithfully without benefit. With the view of ascertaining facts 

 which would lead to methods of prevention, a careful study was 

 made of the conditions under which the outbreak occurred. 



The attending conditions were as follows : All of the milk 

 handled by this dealer was supplied by one dairy consisting of 

 twelve cows. The surplus of milk over that disposed of on the 



* The fact that Bacillus lactis viscosus is an obligate aerobe explains the 

 behavior in milk observed by Adametz. 



