MEAT AND MEAT PRODUCTS. 



107 



cats, rabbits, or guinea I''.~ s may bo used. If the animals sicken and die, they 

 are to lio subsequently examined for the presence of pathogenic bacteria. It 

 may happen that none of the animals thus fed will be injured by the food, 

 which fact would not exclude, however, the presence of a germ requiring a 

 specially susceptible animal for a subject. 



Another set of animals should be injected with a cold extract of the meat 

 made with sterile water. If the animals die, they are to be examined for 

 pathogenic bacteria. A third set of animals should receive similar injections, 

 though of larger portions, of this aqueous extract which has been previously 

 filtered through sterile porcelain. If the animals die from such injections, the 

 same as with uufiltered solutions, it is evident that a soluble bacterial chemical 

 poison is present. 



The identification of the toxin produced by the germ is wholly out of the 

 question. The most that can be done satisfactorily is to obtain, as above, a 

 germ-free solution of the poison. It is wholly unnecessary to devote any space 

 in this connection to the detection of the basic bacterial products, the ptomaines, 

 since these bodies are mere cleavage products produced by some and not by 

 other bacteria. Moreover, they are usually but very feebly poisonous, and 

 therefore are not considered to be as important as formerly.* 



A bacteriological examination proper should be made of the original poisonous 

 moat and of all the animals that died either from eating the meat or from the 

 injections of the aqueous extracts. The organism present in the animal, if any, 

 must be i'solable directly from the meat. If it happens, as it sometimes has, that 

 the dead animals contain no germs, it is proof that they were killed by a toxin 

 elaborated by a germ in the meat previous to the injection. Cultures from the 

 meat will then reveal the germ, and the effects of its pure cultures should 

 correspond to those observed with the poisonous meat. 



To prepare the cultures from the original food, the latter should be cut out 

 with a sterile knife and material should be taken from the inside, thus avoiding 

 all chances of contamination. Several sets of beef-tea tubes and agar plates 

 should be made. One set should be set aside in a Novy anaerobic jar at room 

 temperature ; a second similar set should be placed at a temperature of 37 C. 

 A third set should be grown in the presence of air at room temperature, and a 

 like set at a temperature of 37 C. 



The full details of bacteriological methods must obviously be omitted in this 

 connection. Such work requires a special laboratory and special drill. Those 

 who may be further interested are referred to the works of Abbott, Novy. and 

 Sternberg. 



3. Preparation of Sample for Chemical Examination. Provisional. 



In the case of fresh meat, separate the sample as completely as possible from 

 the bones and pass it rapidly and repeatedly through a sausage mill until 

 thorough mixture and complete maceration are obtained. The sample must be 

 kept on ice to prevent decomposition, and all of the determinations should be 

 begun as soon as practicable after the sample is prepared. In the case of canned 

 meats, pass the entire contents of a can through a sausage mill as directed above. 

 Remove sausage from the casings and mix by repeated grinding in a sausage 

 mill. Dry that portion of the sample which is not needed for analysis, extract 

 with gasoline which boils below 60 C., allow the gasoline to evaporate spon- 

 taneously, and expel the last traces by heating for a short time on the steam 

 bath. Neither the meat nor the separated fat should be heated longer than 



For detailed methods see Vaughan and Novy, " Cellular Toxins," 4th edition, 1002. 



S7404 Hull. 107 O!) 



