REMARKS UPON THE METHODS. 167 



tralized with sodium bicarbonate. Tlie ether extract gave 

 on evaporation a faintly yellow residue, of not unpleasant 

 odor and feebly alkaline reaction. After neutralization 

 with hydrochloric acid, it was only slightly soluble in 

 water. The pale-yellow filtrate gave no precipitate with 

 Nos. 1, 2, 8, 9, and 10 of the above-mentioned reagents, 

 but gave a slight turbidity with Nos. 3, 4, 5, 6, and 7, and 

 with 11 formed Prussian blue. 



GuARBSCHi and Mosso couclude from this and other 

 experiments that the Dragendorff method is not suit- 

 able for the extraction of ptomaines, and they recommend 

 the employment of the Stas-Otto method with these con- 

 ditions : (1) no more acid should be added than is abso- 

 lutely necessary to keep the reaction acid ; (2) the heat 

 used in evaporation should not be great, and it is better 

 that evaporation should be made in vacuo. In this way, 

 they say, no ptomaine will be obtained from fresh tissue. 



The same investigators extracted fresh flesh without the 

 addition of any acid. Thirty kilogrammes of perfectly fresh 

 meat were digested for two hours at from 50° to 60° with 

 about one and one-half volumes of water. The fluids of the 

 meat contained enough acid to give to the whole of this solu- 

 tion an acid reaction. It was evaporated to half its volume 

 on the water-bath, filtered, and evaporated still further. 

 The small residue was taken up with about four volumes 

 of 96 per cent, alcohol. The reddish, alcoholic solution 

 left on evaporation on the water-bath a brownish residue, 

 which was dissolved in water and extracted with ether (A), 

 then the solution was made alkaline with ammonium 

 hydrate and again extracted with ether (B). 



A gave on evaporation and cooling crystals of methyl- 

 hydantoin, while the mother-liquor contained acetic acid. 



B also yielded crystals of methyl-hydantoin, while the 

 mother-liquor gave alkaloidal reactions with most of the 

 general alkaloidal reagents, none with platinum chloride. 

 Methyl-hydantoin does not give these reactions. 



Marino-Zuco has made many comparative tests with 

 these two methods. He ascertained that by treating fresh 

 eggs, brain, liver, spleen, kidney, lungs, heart, and blood 



