66 Mr. Abel on some of the 



cuminic acid was distilled ^vith four times its weight of caustic 

 lime in a copper retort placed in a deep sand-bath, the tem- 

 perature of which was gradually raised to a red heat. The 

 distillate obtained was colourless, possessing however an 

 empyreumatic odour, which it did not lose on being rectified 

 over hydrate of potash to free it from any cuminic acid that 

 might have come over with it. I afterwards found that this 

 peculiar odour was immediately removed on distilhng the oil 

 with a concentrated solution of chromic acid, ^vhich leaves 

 the cumol of its agreeable aromatic smell without affecting its 

 composition. This is a method that might perhaps prove 

 useful in many cases where the peculiar odour of a carbo- 

 hydrogen is disguised by the presence of a small quantity of 

 some foreign substance. 



When dried over chloride of calcium this body possessed 

 exactly the same properties as described by Gerhardt and 

 Cahours. Its boiling-point was found by them to be 144° C. ; 

 a later experiment of Gerhardt gave 1 53° as the boiling-point. 

 The cumol that I prepared boiled at 148° C. Its analysis 

 gave me the following results : — 



0*2029 grm. burned with oxide of copper gave 0*6725 grm. 

 of carbonic acid and 0*1804 grm. of water; corresponding to 



Carbon .... 90*34 

 Hydrogen . . . 9*88 



which numbers agree with the composition of cumol. - 



Theory. Found. 

 18 eqs. Carbon . . 108 90*0 90*34 

 12 ... Hydrogen . __12 10*0 9*88 



120 100-0 



On boiling cumol w ith concentrated nitric acid it is quickly 

 converted into a heavy oil, which is the analogue to nitro- 

 benzol. If the boiling is continued this oil disappears, and 

 is gradually converted into a yellow crystalline mass, soluble 

 in ammonia with the exception of a slight fixed residue (dini- 

 trocumol). The ammoniacal solution gives with hydrochloric 

 acid a white precijjitate, difficultly soluble in cold water, but 

 more easily so in hot water, from which it ciystallizes on 

 cooling. These crystals are generally somewhat coloured; 

 recrystallization after treatment with animal charcoal removes 

 this colouring matter. 



Several combustions of the acid dried at 100° C. showed 

 me that my substance must be a mixture. I therefore di- 

 stilled another portion of cumol with fuming nitric acid for 

 several days, and obtained a crystalline body similar to the 



