12 CONTROL SERIES No. 63 



II. An electrically heated water bath was employed to keep the even num- 

 bered samples warm for 1 hour. The odd numbered samples were handled in the 

 routine manner. The first two days the temperature of the bath was maintained 

 at 36° to 40° C. Later the temperature was maintained at 27° to 32° C. The 

 temperature in the poultry houses varied from 3° to 14° C. at the time of col- 

 lection. Among 744 even samples, 4 (0.5 per cent), and among the same number 

 of odd samples, 227 (30.6 per cent), were jellied. It happened that on the same 

 days, the same blood collectors collected 641 other samples which received 

 routine handling, i.e., as the odd samples, and 220 (31.5 per cent) were jeUied. 



III. An insulated heater, incorporating the principles of a double boiler 

 with hot water as a source of heat, was devised. Alternate samples were placed 

 in this heater at temperatures varying from 21° to 46° C. for periods of 10, 15, 

 20, 30, and 60 minutes. Among the 1,210 samples placed in the heater 67 (5.49 

 per cent) were jellied, while among 1,191 samples handled in the routine way 

 277 (23.25 per cent) were jeUied. In general, jellying was markedly reduced in 

 the samples exposed to the higher temperatures. The longer periods of exposure 

 had a hke influence. A combination of an optimum temperature and an opti- 

 mum period of exposiire was not determined. 



IV. After the clots had been separated, 2,894 samples were divided on the 

 basis of odd and even numbers. The odd samples were centrifuged while the even 

 samples were placed in an incubator (approximately 35° C.) for 1 hour before 

 centrifugaHzation. There were 185 (12.7 per cent) jellied samples among the odd 

 and 112 (7.7 per cent) among the even samples. 



V. Instructions were given to one blood collector to collect approximately 

 0.5 cc. and approximately 1 cc. in alternate tubes. Among a total of 459 samples 

 which he collected in one day, 70.8 per cent of the small and 55.2 per cent of the 

 large samples were jellied. On another day 500 blood samples were collected in 

 accordance with these same instructions. Among a total of 250 samples, 39.6 

 per cent of the small and 20.1 per cent of the large were jellied. The other 250 

 samples of this day's work were placed in an incubator for one hour, just previous 

 to centrifugalization, and 32.1 per cent of the small and 14.1 per cent of the large 

 were jeUied. 



VI. The even-numbered samples of 2,005 received on the day of collection 

 were held over night at room temperature (22°-25° C.) while the odd samples 

 were held in a refrigerator (8° C). There were 46 (4.6 per cent) of the odd and 5 

 (0.5 per cent) of the even samples jellied. There was shght hemolysis in many 

 and marked hemolysis in a few of the samples which were held over night at room 

 temperature. 



From September 29 to December 26, 1930, records were kept on 238,860 

 samples. These samples were collected by sixteen blood collectors and were 

 handled in the laboratory on the day following collection. The number of jellied 

 samples recorded at the time the sera were transferred to the agglutination tubes 

 was 10,886 (4.56 per cent). In individual shipments jellying was recorded in 

 from to 85 per cent of the samples. The correlation between the number of 

 jellied samples and certain temperature ranges is shown in Table 2. The daily 

 mean temperature in Amherst was selected as representative of the State. The 

 mean temperatures were procured from meteorological observations of the Mass- 

 achusetts Agricultural Experiment Station and divided into six groups. The 

 samples were distributed upon the basis of the temperature of the day on v/hich 

 they were collected. 



In 1931, during approximately the same period, records were kept on 270,785 

 samples. These samples were collected by eleven of the 1930 blood collectors and 

 five men employed for their first season. The only difference in the method of 



