164 BACTERIAL POISONS. 



amine, and the volatile fatty acids. The residue after dis- 

 tillation is treated in succession by ether aud by alcohol. 



The extraction with ether (B) separates the ptomaines 

 and some fatty acids. The alcoholic extract (C) removes 

 the remainder of the fatty acids, as well as the acid and 

 neutral nitrogenized bodies, almost all of which are crys- 

 tallizable. The insoluble residue is boiled with dilute 

 hydrochloric acid, with exclusion of air, finally evaporated 

 to dryness, and the residue again extracted with alcohol. 

 This new alcoholic solution (D) can be divided. by acetate 

 and subacetate of lead into two principal portions. 



By operating in this manner the complex products of 

 putrefaction are readily separated into four portions. 



. In his more recent work, GAUTIER has employed the 

 following method : The putrid liquids, after the removal 

 of fats, are feebly acidified with very dilute sulphuric acid, 

 then distilled in vacuo at a low temperature. The distillate 

 contains ammonia, phenol, iudol, and skatol. The syrupy 

 residue, separated from any crystals which may have 

 formed, is rendered alkaline with baryta, filtered, and ex- 

 tracted a great number of times with chloroform, in order 

 to dissolve the bases. The solution is distilled at a low 

 temperature, either in vacuo or in a current of carbonic 

 acid. The contents of the retort, on being treated with 

 water and tartaric acid, separate into a brown resin and a 

 liquid portion. The latter is removed and treated with a 

 dilute solution of potash, when it gives off the odor of 

 carbylamine, which was discovered by GAUTIER in 1866, 

 and which, according to CALMEL, is a constituent of the 

 venom of toads. The alkali also sets free the bases, which 

 are removed by extraction with ether, aud the ether evapo- 

 rated in a current of carbonic acid gas under slight pressure, 

 then under a bell-jar over caustic potash. The bases may 

 be separated by fractional precipitation with platinum 

 chloride, or, if present in sufficient quantity, by distillation 

 in vacuo. 



Still later, GAUTIER has modified his method as follows : 

 The alkaline putrid liquid is treated with oxalic acid (in- 

 stead of sulphuric acid) to free acidulation and as long as 



