574 EXPERIMENT STATION RECORD. 



the city of Dresden, relating to the production and sale of this milk, is given. 

 The health of the cow, the feed, surroundings, and operation of milking are all 

 under strict control. Great importance is attached to giving dry feed as dis- 

 tinguished from all kinds of sloppy feeds, such as distillery waste, silage, and 

 beet tops. The usual sources of carbohydrates are dry hay, wheat bran, rye 

 bran, and small amounts of green fodder cut and taken to the stall. The 

 protein content is brought up to the desired ratio with cotton-seed meal, peanut 

 meal, copra meal, coconut meal, or linseed meal. 



Results secured at the Eacknitz Dairy show that when milk is produced 

 under certain rigid conditions the bacterial content may be kept within safe 

 limits without the necessity of sterilizing by heat. It is stated that the dairy 

 has records showing a count of from zei'o to 280 bacteria per cubic centimeter 

 against 220,000 in good commercial milk. It is shown that in the eight years 

 since the consumption of this milk has begun, infant mortality has decreased 

 from 21.7 to 12.5 per cent in Dresden, and from 17.8 to 5.5 per cent in suburbs 

 of Dresden. 



Comparison of the plating and microscopic m.etliods in tlie bacteriological 

 examination of milk, G. W. Goodrich (Jour. Infect. Diseases, 14 U914), No. 

 3, pp. 512-519). — In comparing the relative value of the plate and micro- 

 scopic methods in the bacteriological examination of milk the author concludes 

 that there is a marked correlation between the two counts; that the factor 

 20,000 which is used to reduce the microscopic counts to terms of the plate 

 count is satisfactory; and that the microscoijic count from a single slide can 

 be depended upon as being within the limits of one-third as great to three times 

 as great as the plate count, but can not be depended upon as being within 

 10,000 of the plate count. The microscopic count from a single slide is not 

 sufBcieutly reliable to warrant the condemnation of market milk, especially 

 when the standard for passing is a low count. Any milk which is " passed " on 

 the microscopic count from a single slide where the passing standard is a low 

 count is not likely to have a dangerously high count by the plate method. 



A bacteriological index for dirt in milk, J. J. Kinyoun (t/. S. Naval Med. 

 Bid., 8 (WUf), No. 3, pp. 43o-^Jt2). — In discussing the relative importance of a 

 bacteriological index for dirt in milk the author concludes after an examina- 

 tion of about 3,000 samples of milk that in good milks there is present on a 

 general average 1 colon bacillus to 50,000 bacteria in the milk ; in dirty milk, 1 

 colon bacillus to 555. He is of the opinion that cleanliness in the production 

 is the most important of all factors entering into the milk problem. The em- 

 ployment of a standardized Endo medium, as described in this article, is recom- 

 mended for isolating the colon group. 



Ability of streptococci to survive pasteurization, S. H. Ayers and W. T. 

 Johnson, Jr. {U. S. Dcpt. Agr., Jour. Agr. Research, 2 (191^), No. J/, pp. 321- 

 330, figs. 3). — The authors of this paper summarize their investigations as 

 follows : 



" The thermal death points of 139 cultures of streptococci isolated from cow 

 feces, from the udder and the mouth of the cow, and from milk and cream 

 showed a wide variation when the heating was performed in milk for 30 min- 

 utes under conditions similar to pasteurization. At 60° C. (140° F.), the 

 lowest pasteurizing temperature, 89 cultures, or 64.03 per cent, survived; at 

 62.8°, the usual temperature for pasteurizing, 46, or 33.07 per cent, survived; 

 and at 71.1° 2.58 per cent of the cultures survived; all were destroyed at 73.9°. 



The streptococci from the udder were, on the whole, less resistant and those 

 from milk and cream more resistant to heat than those from the mouth of the 

 cow and from cow feces. When heated to 60° all of the IS cultures from milk 

 and cream survived ; at 02.9° 17, or 04.44 per cent survived ; at 68.3° 9 cultures. 



