912 EXPEKIMKNT STATION KKCOKD. 



us ftnii|iai('il Willi ;in ;i\rr;iL,'r (if ■_'.'),()()() d > all, 000 icporlcd liy I larrisi ui and ( 'miimiiiii. 

 The most si rikiiit;- liirrciciicc, lidwcvfr, rdatcil to tlif s|>((ic-; nf hacteria pivseiit. In 

 the work of I larrisoii ami CiiimiiiiiL,' over '.)■") jxt cent of t he b ictcria were reiuirted 

 as heloiijiing to llu' lactic-acid ;,n-oii|> and inclndin;^ llaclci-inm Im-tis nciill. In the 

 work in (!oniu'cticnt, involving luindrcds of experiments carried on in the two 

 localities meiilioned, the laclic-acid liacteiia w ere commcjiily less than 50 per cent 

 and often below ;;(i piT cent; and in pra<-ticall\' no instance was the Bdrtrriiini lacth 

 r?r/f// present. The differences are attributed in part to local con<litions, but mainly 

 to till' different methods of analysis used. The author attributes the tliscrepancies 

 in results to the use by Ihn'risctu and Cununing of ordinary gelatin in the prepara- 

 tion of plate cultures and the subsequent isolation and study of only a limited num- 

 ber of colonies. 



Dairy bacteriology laboratory, AV. A. Stocking, Jr. {Cunueciicat Sturr.s Sin. RpL 

 I'jdo, />/). ..'..'-,.'7, Jii/x. -v). — This is an illustrated description of the new dairy bacterio- 

 logical lalioratory at the Connecticut Storrs Station. 



Milk bacteria, C. Hai'pich [Fotisclir. Vet. Jfi/'j., 1 (UMIJ), Xo. .',, ]ip. l.',U-151). — 

 The bacteria found in milk are classified as indifferent, useful, harmful, and patho- 

 genic, and each class is descriljed. 



Milk fermentations, M. A. O'Cam.aguan {A(jr. Gaz. Nen: SdiiIJi ll'^/fs, ]'> [1904), 

 N). i,\ ]>p. Ill, 11.', j)h. ■!). — Notes are given on the use of boric acid in the preserva- 

 tion of normal milk, condensed milk, and concentrated milk. In experiments 

 which are l)riefly reported the development of lactic-acid Ijacteria was very materi- 

 ally checked in fresh milk by the addition of 0.25 and 0.50 per cent of boric acid, 

 while this (juantity of preservative did not appear to retard butyric-acid fermenta- 

 tion in the slightest. In concentrated milk the use of 0.25 to 0.50 ])er cent of boric 

 acid appeared to check tlie growth of nearly all species of bacteria. 



Th.e soluble ferments of cows' milk, J. Lesperance [Med. Bee. [AVm; York], 65 

 (1904), ^^0. 13, pp. 447-450). — This is a general discussion of the subject. In sum- 

 marizing the discussion the author states that the'presence of peptic, tryptic, lipasic, 

 oxidizing, and glycolytic ferments in milk have been definitely determined. A 

 biI»liograpliy is appended. 



On the coagulation of milk, A. S. Loevenhart ( Zd^rlir. I'lii/siol. ( 'linn., 41 ( 1904), 

 No. S, pp. 111-^05). — Some of the results of the investigations here reported may be 

 summarized as follows: In regard to the action of their salts on casein and para- 

 casein, metals rnay be divided into o groups — grouji 1 including sodium, potassium, 

 ammonium, and possibly also rubidium and cesium, the salts of which precipitate 

 neither casein nor paracasein; group 2 including the salts of lithium, beryllium, 

 magnesium, calcium, strontium, barium, manganese, iron, cobalt, and nickel, which 

 precipitate paracasein readily at room tem]ieratures, but casein only after a long time 

 at 40° C. or above; and gnjup 3 including all the other heavy metals and ferric iron, 

 the salts of which jirecipitate both casein and paracasein promptly at room tempera- 

 tures. The isrecipitating action of the salts increased in proceeding from the stronger 

 to the weaker metals. 



Paracasein was precijjitated more readily than casein by all the reagents. Para- 

 casein and casein are Ijelieved to differ only in their i)hysical nature, and are, there- 

 fore, modifications of one and the same substances. The coagulation of milk is 

 believed for the most part to depend upon a change in the arrangement of the 

 mineral constituents of milk. The calcium salts present in milk do not exist origi- 

 nally in a form capable of i)recipitating the casein or paracasein, but are made avail- 

 able for this purpose during the action of the rennet. 



A study was made of the nietacasein reaction of Rol)erts, which consists in the 

 addition of pancreatic extract to milk l)y which the milk, while not apparently 

 changed, is nevertheless rendered capable of being coagulated by heat. This 

 was found to be directly dependent ujion the presence of calcium salts, and could 



