M. Erlenmeycr on Propyle Compounds . 109 



of ammonia. Erlenmeyer expected by the action of the iodide 

 on oxide of silver to obtain propylic alcohol, in accordance with 

 the equation 



2G 3 H 7 I + Ag 2 G-fH 2 = 2G 3 H 8 G + 2AgI. 



He accordingly heated iodide of propyle with moist oxide of silver 

 in a flask connected with a condensing arrangement. He ob- 

 served the disengagement of a gas which a subsequent experi- 

 ment showed to be propylene, the formation of which may be 

 thus expressed : — 



2G 3 H 7 I + Ag 2 0-2G 3 H 6 + 2AgI + H 2 G. 



Iodide of Propylene. 



propyle. 



The contents of the flask consisted of iodide of silver with two 

 liquids. After adding water, the flask was heated until the ther- 

 mometer rose to 100°. The distillate consisted of two separate 

 layers, an aqueous inferior layer, on which swam a mobile 

 body with a peppermint odour. Water was added to the two 

 liquids, whereby a larger quantity of this lighter liquid was sepa- 

 rated. Washed with water, dried over chloride of calcium, and 

 rectified, it passed over completely between 60" and 62°, and was 

 found on analysis to consist of propylic ether, G 6 H 14 G. The 

 formation may be expressed as follows : — 



= j?5 7 7 \o+2AgL 



Iodide of £ 3 H ' 



propyle. Propylic 



ether. 



Its formation may also be otherwise expressed; but in any case 

 its production in a liquid containing excess of water is of interest 

 to those who consider that ethers only result from a dehydrating 

 process. 



The aqueous layer formed in the above operation was distilled 

 on the water-bath, the distillate saturated with carbonate of pot- 

 ash, and the liquid separated from the carbonate of potash dehy- 

 drated by means of anhydrous sulphate of copper. When distilled 

 it passed over at 80° C, and was found on analysis to have the 

 composition of ordinary alcohol, G 2 H 6 O. The formation of this 

 alcohol appeared, however, so unusual, that Erlenmeyer was led 

 to the idea that the substance might be a special hydrate of pro- 

 pylic alcohol, of the composition 2 G 3 II 8 G -f H 2 G, which repre- 

 sents threefold the composition of ordinary alcohol j for 



G 6 H 18 G 3 = 3G 2 H 6 G. 

 It was accordingly again dehydrated over dry sulphate of copper 

 and, on rectification, distilled at 82°. The analysis gave, how- 

 ever, too small an amount of carbon for propylic alcohol. Erlen- 



