Yeast-Precipitins 155 



earlier paper (Sitzung. der Gesellschaft der Charitearzte, 12, xii. 1901) 

 wherein he reported success in obtaining yeast-precipitins. He ex- 

 tracted yeast-albumin by rubbing up yeast in a mortar in sterile 25 / 

 soda solution, facilitating the rupture of the cell membranes by the 

 addition of powdered glass and sand. The thick paste at first formed 

 soon became fluid and thin, and a clear fluid was obtained by ccntri- 

 fugalizing off the sand and cellular detritus. The clear fluid was 

 injected in doses of 5 10 c.c. every 3 4 days, during two months, into 

 rabbits, a total of 100 c.c. being administered. 



In this way he treated rabbits with yeast-albumin of four kinds : 

 Potato yeast, Baker's yeast, Top and Bottom Beer yeast. When he 

 came to test the antisera he found that all the yeasts reacted to the 

 various antisera, in other words that it was not possible to distinguish 

 the species of yeasts by means of these precipitins. 



Precipitins for Albumins of Higher Plants. 



Kowarski (4, vn. 1901) injected wheat albumose 1 into rabbits, 

 obtaining precipitins, which acted promptly on wheat albumose in 

 solution, less markedly on rye and barley, but not on corresponding 

 solutions from oats ; peas giving a very weak reaction (faint clouding). 

 Normal rabbit serum had no such effect. 



Schlitze (22, xi. 1901, p. 493) treated rabbits with a vegetable 

 proteid " Roborat," obtaining an antiserum which precipitated roborat 

 solutions, but not muscle albumin, the antiserum for the latter having in 

 its turn no effect on roborat solutions. Castellani (28, VI. 1902, p. 1828) 

 confirmed this observation, finding that anti-roborat did not act on 

 somatose solutions. He also appears to have produced a weak anti- 

 somatose, which had no action on roborat solutions. 



Jacoby (1901, cited by Bashford) found that animals which had 

 been rendered immune to ricin yielded a serum, which, whilst anti- 

 toxic, gave a precipitum on being added to ricin solutions. Bashford 

 (1902, Journ. of Pathol. and Bacterial. VIII. p. 59) states that he has 

 recently made a similar observation in rabbits treated with crotin. The 

 rabbits' serum gave a dense precipitum with a solution of crotin, normal 

 rabbit serum not exerting this effect 2 . 



1 These results are to be received with caution, see p. 111. 



- Note analogous observations on suake venom, see Section VI. 



