2i8 Journal o[ Agricultural Research voi. xvii. no. s 



Experiment 28 (September 8. 1914). — The eviscerated carcass of a 

 trichinous rat was heated 17 hours in an oven at a temperature of 48° 

 to 50° C. On removal from the oven the carcass had a bad odor; the 

 upper surface was dried, the lower still moist. Twenty trichinae were 

 dissected out of the meat after heating and all found to be dead. Meat 

 from the carcass was then fed to two rats, one of which remained free 

 from trichinae, while the other was found moderately infected when 

 killed three months after feeding. 



Kxl'ERiMENT 29 (September 19, 191 4). — Finely chopped meat from a 

 trichinous rat was heated 5 hours in an oven at a temperature of 48° to 

 49° C. A few trichinae afterward dissected out of the meat were shrunken, 

 but their protoplasm was bright in appearance. After being soaked in 

 water for 30 minutes some of the lar\-ae became lively, and 2 days later 

 the remainder of the isolated larvae kept in water at room temperature 

 had also become actixe and normal in appearance. Some of the same 

 meat was left in the oven until September 21, and thus exposed for 48 

 hours to a temperature of 48° to 49° C. It was hard and dry. Trichinae 

 isolated from the meat by dissection after it had been softened by soaking 

 were very clear, pale, motionless, and apparently dead. 



Additional data regarding the effects of the continued action of tem- 

 peratures below the thermal death point were obtained by the junior 

 writer. In these experiments, which are summarized in tabular form 

 (Table II), the method of procedure was as follows: Meat from trichinous 

 hogs was finely chopped by passing it through a meat chopper several 

 times. A bottle with a capacity of about 200 cc. was half filled with 

 the meat. Through a perforation in the cork a thermometer was inserted 

 into the bottle and the top of the cork then paraffined. The bottle of 

 meat was placed in a constant-temperature oven and the temperatures 

 read on the thermometer in the bottle. 



Inasmuch as the meat before being placed in the oven was kept in a 

 refrigerator at a temperature of S° to 10° C, a considerable period was 

 required to bring its temperature near that of the oven. In nearly all 

 the experiments shown in Table II the meat was in the oven about 2 

 hours before the first reading of the thermometer, given in the table as 

 the minimum temperature, was made. Between the first and the final 

 reading there was a slight fluctuation of the temperature but nearly 

 always between the limits recorded in the table. 



At the end of each experiment a portion of the meat was artificiallv 

 digested in the usual way and the condition of the larvae noted. As a 

 control on the microscopic findings in each experiment two rats were 

 fed portions of the meat, being given an average of about 10 gm. each. 

 Unless they died earlier the test animals were killed about a month after 

 feeding. The following table gives the record of i o experiments : 



