322 H. B. TAYLOR. 
most favourable for their growth, it is quite possible that 
in the short time the milk is in the udder some catalase 
could be produced. To see whether it was possible for 
bacteria from the air to form catalase, some milk was 
boiled and divided into two parts, one being closed from the 
air by means of cotton wool, the other left open. In the 
course of two days at a temperature of 25° CO. the one left 
open gave a value for & of °00323, while that kept closed 
did not decompose hydrogen peroxide at all. It was also 
noticed that in milk kept for some time the amount of 
catalase increased, as shown by the increased value of £; 
this action could also be attributed to the action of bacteria. 
Table III. 
Temperature 25° C. 
Concentration of K x 10+ Total H,O¢ 
hydrogen peroxide. Age of Milk. decomposed. 
(1). M28 : 2 hrs. 52 min. 97 er) 
27 ” 53 ” oh 1°36 
(2) -M/35 Oe) liens, 29 i 
2 ” 35 ” efets 1:07 
3 bb) 30 99 eee 1°15 
22 ” 10 ” 141 1°68 
(3) M/35 2 99 15 “rn 56 1:25 
4 99 0 99 eee 1°30 
ao 4 «=O Gy 340 1:70 
sail 99 30 ” 156 1°36 
50 ,, 25°, 97 
22 he) 30 bb) 235 1°59 
27 ” 7 ” 186 1°39 
47 ” 10 ” Vie 1°30 
51 be) 25 99 89 1°21] 
