C. M. Warren on the Volatile Hydrocarbons. 105 
reaction between the baryta and cuminicacid as being much 
more simple than my experiments seem to indicate. On this 
point they remark: “The formation of cumene is easily explain- 
ed. In effect, the cuminic acid being represented by C, , pe 
it appears that C,O,, that is to say, 2 equivalents of carbonic 
acid, are retained by the baryta, while C,,H,, are set free,’™ 
©, Hy.0, = 0,0, +0,.H.,.. : 
In another place (p. 88) they remark, that “ by suitably man- 
aging the heat, and employing no more than 6 gr. of cuminic 
acid at a time, no other products are ever obtained than those 
which we mention.”** My experiments show that this reaction 
is by no means so simple as thus described. The crude product 
obtained from the mixture of lime and cuminic acid, when sub- 
jected to a simgle distillation from a tubulated retort, was found 
to distil between 155° and 250°, leaving a residue at the latter 
temperature which became semi-fluid on cooling. The distillate 
thus obtained gave, by my process of fractional condensation, an 
the probability of deciding the question. ‘There is evidence, 
1 ours 
was not simply pure cumole, as they described it, but a mixture 
being so considerable, may be more reasonably accounted for 
on the supposition that they operated, in the first instance, upon 
a mixture of different bodies; and yet I cannot see how they 
could have obtained the product boiling below 150°. Additional 
evidence on this point will be found in the discrepancy which 
appears between their determination of the vapor density, and 
that calculated upon theory. 
* «Ta formation du cuméne s'explique aisément. En effet, acide cuminique 
etant représenté par C,,H.,,0, on voit que C,0,, cest-adire 2 equivalents 
Wacide carbonique sont retenus par la baryte, tandis que C3,H,, sont dégagés. 
—Annales de Chimie et de Physique, 1841, [3], i, 89. : 
* “ En dirigeant la chaleur convenablement et en n’employant, pas plus de 6sr- 
acide cuminique a la fois, on n’obtient jamais d’autres produits que ceux que 
enons de nommer,” : : 
* Annales de Chimie et de Physique, 1845, [3], xiv, 107. 
Am. Jour. Sct.—Seconp Series, Vou. XL, No. 118.—Juxy, 1865. __ 
14 
