58 STORRS AGRICULTURAL EXPERIMENT STATION. 



the labor, therefore, in later experiments we made our exami- 

 nations of the milk kept at 13° at longer intervals; in the 

 records of experiments which follow it will be seen that the 

 cooled sample of milk was tested once in twelve hours, and 

 the tests were continued for a period of about fifty hours, 

 thus making the number of tests in the two samples of milk 

 identical. The tests are thus of course not strictly parallel 

 with each other in the two samples because they were made 

 at different intervals; but it is impossible to make exactly 

 parallel tests. The conditions of the milk kept at the two 

 temperatures is so unlike that there was no time in the whole 

 experiment where the one sample could, from a bacteriological 

 standpoint, be compared with the other. 



Several of the earlier experiments in this line were quite 

 unsatisfactory because of improper understanding of these 

 conditions. The milk which was kept at the temperature of 

 13° was, in the early experiments, diluted very much too 

 highly, inasmuch as we anticipated a greater growth of bac- 

 teria than occurred. Tests were also made too frequently, 

 and other difficulties appeared, so that our first experiments 

 were quite unsatisfactory as concerns any comparison between 

 the milk at 20° and the milk at 13°. These experiments are 

 not reported here; the only ones which are given are those 

 performed after we had learned sufficient about the results 

 to be able to plan the experiment a little more satisfactorily. 



Experiment No. 10. January. — Tables 23-26 show the re- 

 sults that were obtained in this experiment. The preliminary 

 test of fresh milk was unsatisfactory because of the presence 

 of too large a number of liquefiers. 



The most suggestive facts to be noticed from these tables are 

 as follows: 



I. Perhaps the most extraordinary and surprising feature 

 is seen in the comparison of the total numbers of bacteria in 

 the two samples of milk. In the sample kept at 20° the number 

 increased regularly, reaching 18,000,000 in the course of 

 twenty-eight hours. It was to be expected that the number 



