1867.] 



of the Series C" H^^+s. 



35 



flask is heated in an oil-batli, and the Hquid contents are distilled off. The 

 distillate is fractionated several times, and the portion boiling between 50° 

 and 70° C. collected separately. This consists chiefly of di-isopropyl, but 

 also contains ether, undecomposed iodide of isopropyl, and may also con- 

 tain diallyl if the iodide was not quite pure. In order to remove these ad- 

 mixtures, the liquid is repeatedly shaken with concentrated sulphuric acid 

 as long as heat is evolved, then rectified, and the distillate treated with a 

 mixture of strong nitric and sulphuric acid as long as iodine separates, then 

 washed, dried, and rectified over potassium. 



Di-isopropyl is a colourless mobile liquid, the odour of which cannot be 

 distinguished from that of hydride of hexyl, and which boils constantly at 

 58° C. The specific gravity was found to be 



at 10° C. = 0-6769, 

 at 17°'5 C. = 0-6701, 

 at 29° C. = 0-6596. 

 The analysis gave the following numbers : — 





Calculated. 



Found. 



72 



83-72 



83-5 



14 



16-28 



16-4 



86 



100-00 



99-9 



Co 



86 100-00 99-9 



rcH 



The formula for isopropvl now generallv accepted is \ CH , and the 



constitution of di-isopropyl may therefore be expressed by the following 

 formula: — f H 



i CH., . 



n ch; 



I CH.. ■ - 



This hydrocarbon can be considered as hydride of ethyl, in which 4 

 atoms of hydrogen have been replaced by methyl and might be called, by 

 accepting the nomenclature for hydrocarbons proposed by Hofmann*, 

 tetramethyl-ethan . 



Chlorine attacks this hydrocarbon very easily in the cold, and if the 

 action is stopped before the whole has been acted upon, the principal sub- 

 sti'tution-product consists of the chloride C^ H^3 CI, a colourless liquid which 

 boils constantly at 122° C, and very closely resembles its isomer, chloride of 

 hexyl, the boiling-point of which is 125° C. according to a determination 

 made with the same thermometer. The specific gravity of this chloride is 



at 14° C. = 0-8943, 

 at 22° C. = 0-8874, 

 at 34° C. = 0-8759. 



Proc. Eoy. Soc. vol. sv. p. 57. 



D 2 



