DAIRY FARMING — DAIRYING. 875 



Sixty per cent of the cities in group 1 and 45 per cent in group 2 require the 

 tuberculin testing of cows supplying milk, or tluit the milk shall either come 

 from tuberculin tested animals or be pasteurized. Fifty per cent of the cities 

 in group 1 control pasteurization by ordinance, while only 25 per cent of the 

 cities in gi-oup 2 do so. Thirty per cent of the cities in group 1 and 4 per cent 

 in group 2 require milk to be delivered within a specified time, the prevailing 

 time limit in group 1 being 24 hours. Thirty per cent of the cities in group 1 

 and 9 per cent in group 2 prohibit repasteurization. Forty per cent of the 

 cities in group 1 and 18 per cent in group 2 have a minimum score below 

 which no dairy may sell milk. Eighty per cent of the cities in group 1 and 

 34 per cent in group 2 prohibit the sale of dipped milk. 



The iron content of cow milk, F. E. Nottbohm and G. Dorr {Ztschr. 

 Untersuch. Nahr. u. Oenussmtl, 28 {lOU), No 9, pp. 4i7->J2//).— Analytical daUi 

 are given which showed the iron content of the samples tested (determined as 

 FesOs) to be from 0.03 to 0.13 mg. per 100 cc. 



The presence of Bacillus abortus in milk, Alice C. Evans {Abs. in Science, 

 n. ser., 42 {1915), No 1080, p. 352).— It has been found that the bacillus of 

 contagious abortion occurs commonly in certified milk in the vicinity of Wash- 

 ington, D. C, and Chicago, 111. The organism grows profusely on serum agar 

 plates. About 30 per cent of the samples of milk from two certified dairies near 

 Chicago which were plated on serum agar showed this organism to be present 

 in milk at the time of drawing from the udder in numbers varying from 110 to 

 4,300 per cubic centimeter. In one sample taken from a herd which does not 

 produce certified milk, 50,000 of the B. abortus were found per cubic centimeter. 

 This organism grows abundantly in the cream layer, with the formation of 

 acid, but sparingly in milk from which the cream has been removed. Four 

 per cent of lactic acid in the milk does not check the multiplication of B. 

 abortus in the cream layer. 



A simple test for Bacillus sporogenes in milk and water, J. Weinzirl 

 {Abs. in Science, n. ser., 42 {1915), No. 1080, p. 353).— The sample of milk to 

 be tested is placed in a sterile test tube, enough solid paraffin is added to make 

 when melted a layer one-eighth of an inch in thickness, and the tubes are 

 heated at 80° C. for ten minutes. After heating, they are cooled rapidly ; this 

 causes the melted paraffin to solidify and form a cover which effectively ex- 

 cludes atmospheric oxygen. Tlie cultures are then incubated at 37° for 24 

 hours. If B. sporogenes is present, it digests the lactose and forms a gas which 

 lifts the paraffin plug. 



The test is deemed simple, cheap, and easy of application. When applied to 

 market milk it gave the following results : Ninety samples of 5 cc. of milk each 

 gave 28 per cent positive ; 112 samples of 10 cc. of milk each gave 37.5 per cent 

 positive ; and 34 samples of 15 cc. of milk each gave 50 per cent positive. 



ISTvimbers and efficiency of Bacillus bulgaricus organisms in commercial 

 preparations examined during" the period January to June, 1914, Rutu C. 

 Greathouse {Abs. in Science, n. ser., 42 {1915), No. 1080, p. 352).— Samples of 

 commercial preparations of B. bulgaricus, containing in the case of dry cultures 

 from none to 250,000 living B. bulgaricus per gram, in the case of liquid cul- 

 tures from 2,800 to 320,000,000 per cubic centimeter, and in the case of sour 

 milk drinks from 800 to 790,000,000, were examined. 



The maximum acidity produced in milk by the B. bulgaricus in these prep- 

 arations varied from 1.2 to 3.41 per cent of acid, calculated as lactic. The 

 ability of the B. bulgaricus to produce acid was decreased in the old prepara- 

 tions The amount of decreases averaged 38.5 per cent in the case of dry cul- 

 tures kept on ice for two months and 26.4 per cent in the case of liquid prep- 

 arations kept on Ice for two weeks. 



