224 Dr. A. von Planta and Mr. W. Wallace on Apiine^^/ 



VIII. Compound with hydrochloric acid^. ■■■■"■' • '^ 



As apiine wlien dissolved in hydrochloric acid and precipitated 

 by being thro^^ai into cold water acquires a yellow coloui*, we 

 thought it probable that a combination was formed which was 

 decomposed by washing with water. 



There not being any definite compound of apiine with a base 

 by which its combining proportion could be determined, it was 

 considered of the highest importance that a combination with 

 hydrochloric acid should, if possible, be effected. Some very 

 careful experiments were therefore made, but without success, so 

 far at least as the determination of the equivalent number is con- 

 cerned. However, as the experiments were interesting, they 

 will be given, and likewise the equivalent which might be de- 

 rived from them. 



Pure and perfectly diy apiine was put into a U-tube, and hy- 

 di'ochloric acid gas, prepared from common salt and oil of vitriol, 

 and dried by being passed through concentrated sulphuric acid, 

 was conducted over it for from ten to fifteen minutes. A con- 

 siderable volume of air, dried by passage over chloride of calcium, 

 was drawn through the apparatus, which was then corked up 

 and reweighed. The apiine in this process became of a bright 

 golden yellow colour, just like when the solution in strong hy- 

 di'ochloric acid w as poured into cold water, Two experiments 

 gave the following results : — 



I. 0"4030 grm. absorbed 0206 grm. hydrochloric acid, pr 

 100 = 5-111. 



II. 0-3602 grm. absorbed 0-0185 gnn. hydrochloric acid, or 

 100=5-133. 



This would make the equivalent of apiine 712, w^hich would 

 give its formula, as nearly as possible, C^^ H^^ 0^, or — 



Found. 



I. II. III. IV. 



65 Carbon . . 390 55-0 55-25 55-05 5455 54-87 



39 Hydrogen . 39 5-5 559 5-49 5-60 5-74 



35 Oiygen . . 280 39-5 3916 39-46 3985 39-39 



709 100-0 10000 100-00 10000 100-00 



On heating this compomid (?), however, in a water-bath for a 

 few minutes, it regained its original colour, and became indeed 

 pure apiine, containing not a trace of hydrochloric acid. Its in- 

 stability was so great, that even when exposed to the air it 

 emitted hydi'ochloric acid, which was quite perceptible by its 

 odoui*. 



We therefore consider this substance not a combination, but 

 as apiine holding hydi'ochloric acid hygrometrically, or, what is 



