186 TOXINES AND ANTITOXINES. 



dried them, extracted them with water, and treated the extract 

 with alcohol. 



Great theoretical interest attaches to ricine owing to the fact 

 that EHRLICH l has made it the starting point of his fundamental 

 investigations of antitoxic immunity. He, too, separated it from 

 the seeds by extraction with a 10 per cent, solution of sodium 

 chloride, and purified it in exactly the same way as STILLMARK. 

 Merck's preparation is precipitated from the sodium chloride 

 solution by means of ammonium sulphate. 



Chemical Nature of Ricine. While the older investigators 

 regarded ricine as a proteid, the progress of discovery appears 

 to follow the same course here as was described in the case of 

 the bacterial toxines, and, with the increase in the accuracy 

 of the investigations, the belief continues to gain ground that 

 this toxine, although a body of high molecular weight, is not a 

 proteid in the narrower sense of the term. 



STILLMARK regarded it as a globulin. CUSHNY S made many 

 tedious experiments to prove that ricine was really a proteid, 

 or to free it from proteid impurities, but did not obtain any 

 definite results. It is quite impossible to effect a separation of 

 the active principle from the proteids by the usual methods, 

 either because the coefficients of precipitation and re-solution 

 are the same, or, more probably, because ricine, like so many 

 colloidal substances, is mechanically carried down by many 

 precipitates as they fall, and especially by coagulated albuminous 

 substances, &c. 



Eventually the resistance offered by ricine to trypsin afforded 

 a means of preparing a substance which, in all probability at 

 least, was not of a proteid nature. This property, which was 

 denied by STILLMARK, but demonstrated by CUSHNY and 

 MiJLLER, 3 formed the starting point for JACOBY'S* striking 

 experiments. 



He first showed that, even after being digested for a week 

 with trypsin, the toxic power of ricine remained unaltered, the 

 same result being also obtained with papdin. But he did not, of 

 course, draw any definite conclusion from this alone, since it was 

 possible that the proteids might also be able to resist the action 



1 Ehrlich, "Exper. Unters. uber Imimmitat," Deutsch. med. Woch., 

 1891, 976, 1218; " Zur Kenntnis d. Antitoxinwirkg.," Fortschr. d. Med., 

 1897, 41. 



2 Cushny, " Ueb. das Ricinusgift," Arch, exper. Path., xli., 439, 1898. 



3 Miiller, "Beitrage z. Toxikol. des Ricins," Arch, exper. Path., xlii., 

 302, 1899. 



4 Jacoby, "Ueb. d. chem. Natur des Ricins," Arch, exper. Path., xlvi., 

 28 (reprint). 



