153 



Dr. Hofmaim on a Neiv Series of Bodies [Rece&s, 



As several preliminary experiments gave indications of a rather com- 

 plicated reaction, and as it would have been difficult for me readily to 

 obtain sufficient substance by operating in sealed tubes, I performed the 

 experiment in the amylic series, supposing that the higher boiling-point 

 of the iodide of amyl would render it more easy of attack. My expectation 

 was indeed fulfilled : two molecules of cyanide of silver and one molecule 

 of iodide of amyl act on one another with extreme violence at the boiling- 

 point of the latter. It is convenient to operate on a moderate scale, so as 

 to be carefully protected from the escaping gases, which consist of equal 

 volumes of amylene and hydrocyanic acid, mixed with a small quantity of the 

 cyanide of amyl. 



The experiment was made in a retort adapted to the lower end of a 

 condenser, the upper end of which was connected with a series of wash- 

 ing-bottles. In the first a small quantity of cyanide of amyl was con- 

 densed ; the second contained water intended to absorb the hydrocyanic 

 acid ; the third one water and bromine in order to transform the amylene 

 into bromide, of which I was thus enabled to collect a considerable 

 quantity during my researches. 



After an hour's digestion, the reaction is finished, and the residue in 

 the retort consists of a dark viscous mass, becoming almost solid on cool- 

 ing ; this is a mixture of iodide of silver and a combination of cyanide of 

 silver and cyanide of amyl. The reaction then takes place according to 

 the equation : — 



C^H,,! + 2AgCN = Agl + AgCN, C, H^, CN. 



Iodide of amyl. Cyanide of silver. Compound of cyanide of 



silver and cyanide of amyl. 



But simultaneously a certain quantity of cyanide of amyl splits into amy- 

 lene and hydrocyanic acid : — 



C,H,,CN = C^H,, + CHN. 



Cyanide of amyl. Amylene. Hydrocyanic 



acid. 



This secondary transformation depends principally on the manner in whicli 

 the operation is conducted ; it m,ay give rise to very great loss if the re- 

 action be rather tumultuous. 



It was now necessary to separate the cyanide of amyl from the residue in 

 the retort. Up to the present time I have found no other means of effecting 

 this than by submitting the residue to dry distillation ; in this operation a 

 further quantity of hydrocyanic acid and amylene is disengaged, and a 

 liquid distils over, which on rectification boils between 50° and 200°. By 

 submitting it to fractional distillation it was found that the first part still 

 contained a quantity of amylene, whilst the latter products had become 

 inodorous. The intermediate portion, rectified several times, finally exhi- 

 bited a constant boiling-point between 135° and 13/°. 



