Tests ivith Precipitins 405 



almost as much reaction with goat as with sheep, and less reaction with 

 beef extract. The method is of no especial use in the examination of 

 large pieces of meat, for the reason that these can be readily recognized. 

 Tokishige has informed Uhlenhuth that meat is usually sold in small 

 pieces in Japan. Minced meat is sold in most countries. Admixtures 

 of horse, dog, and cat meat can be detected by the precipitin method in 

 minced meat, in sausage, and smoked meat, these of course not having 

 been subjected to cooking. He obtained reactions with pig and horse 

 hams which had been smoked the year before, also with horse sausage 

 (" Pferdemettwurst "). 



The method of examination consists in scraping the meat and 

 extracting it with water or saline. It takes a long time to extract the 

 meat in some cases. An extract is suitable for testing when it foams 

 on being shaken. Meat can be more rapidly extracted by adding a 

 small amount of chloroform, extraction being then usually effected in a 

 few minutes. The extract is very cloudy, and has to be cleared by 

 repeated filtration through filter-paper or a Berkefeld filter. If extracted 

 with water, an equal volume of double normal salt solution has to be 

 added to the watery extract before testing this. In testing add 

 10 — 15 drops of antiserum to 3 c.c. of the saline meat extract. 



Von Rigler (1902) has used this method in the study of meat- 

 adulteration. He prepared 20 "/o watery extracts of the meat of 7 

 species of animals (roebuck, hare, rabbit, horse, ox, pig, cat) and 

 injected 5 — 10 c.c. thereof every 3 days into rabbits subcutaneously, 

 during one month. Whereas normal rabbit serum had no effect on the 

 meat extracts, the antisera obtained from the treated rabbits were 

 specific, acting on extracts of mixed meats, as also upon some boiled 

 and roasted meats of an homologous kind. 



Notel (13. III. '02) treated rabbits with horse serum, muscle juice 

 and muscle extract (in '1 "/o soda solution) injecting subcutaneously 

 every 2 to 3 days, amounts of 10 c.c, until 10 to 12 doses had been 

 administered, after which 6 days were allowed to elapse before the 

 rabbits were bled. He obtained the least effective antisera from the 

 serum -treated rabbits ^. 



To obtain clear solutions of muscle, he found it best to extract by 

 means of "1 "/o soda solution, without disturbing the meat mechanically. 

 He found roasted meat, underdone in the centre, as also cold-smoked 

 meat, to give positive reactions. Donkey meat reacted like that of the 



' Vallee and Nicolas (30. vi. '03) have recently confirmed these observations. They 

 speak of sero-precipitins in contradistinction to musculo-precipitins. 



