RESEARCHES ON THE VOLATILE HYDROCARBONS. 139 
identical with the hydrocarbon existing in oil of cumin. It thus appears that of the. 
four bodies which Mansfield detected in coal-tar naphtha, benzole is the only one 
which he had studied in any detail. Indeed he distinctly states that the others had 
not yet been isolated in such a state of purity as to entitle them to analysis. And 
yet his conjectures as to the identity of these bodies, thrown out by way of prelimi- 
nary notice of results which were acknowledged to be incomplete and inaccurate, have 
nevertheless been extensively quoted, and generally received as established facts. 
In addition to the bodies already mentioned, Mansfield also detected the presence of 
a body more volatile than benzole, having an alliaceous odor, which he found to boil 
between 60° and 70°. Ritthausen* made a re-examination of the light coal-tar naph- 
tha, in order to obtain the hydrocarbons in a state of greater purity, and to prove the 
correctness of Mansfield’s view of the composition of this naphtha. In regard to the 
results which he obtained, he says they fully confirm those of Mansfield. Of the 
body which Mansfield designated as probably identical with cymole, and of the oil 
more volatile than benzole, Ritthausen obtained quantities too small to admit of 
investigation. In regard to the latter, however, he remarks, that to Mansfield’s 
account he can add, that “its nitro-product quite resembles that of benzole, and hence 
that at all events it belongs to the series C,H,_,, and perhaps has the formula 
C,,Hy.”t Itis to be regretted that Ritthausen also omitted to analyze and determine 
the vapor density of any one of these substances, he having added, therefore, nothing 
more than a confirmation of the results of Mansfield. He gives the boiling-point of 
benzole at 80°, of toluole at 109°, and of the so-called cumole at 139- 140°, which will 
be found to agree very nearly with my own determinations. Church,§ in the follow- 
ing year, published a paper on the “ Determination of Boiling-points” in the “ Ben- 
* Journal fiir praktische Chemie, 1854, LX. 74. 
¥ “Ich kann den Angaben von Mansfield iiber das letztere nur das hinzufiigen, das seine Nitroproducte 
denen des Benzols, etc. ganz ahnlich sind, daher es jedenfalls der Reihe C, H,_, angehért und vielleicht die 
Formel C,) Hy, besitzt.” 
¢ On a future occasion I shall show that Ritthausen was in error in placing this body in the benzole series, 
and indeed in considering it as a hydrocarbon at all. He was evidently deceived by operating on a mixture 
containing benzole. Furthermore, as Mansfield suggested might be possible, that part of the naphtha more 
volatile than benzole is by no means composed of a single substance. Having had a large quantity of this 
volatile material at my command, I have been able to obtain the separate constituents apparently in a state of 
great purity. Of the two bodies separated, one of them boils constant at about 40°, and the other near 0°. 
Both are compounds containing sulphur, and therefore will more properly form the subject of a separate 
paper. 
§ Philosophical Magazine, 1855, 4th Series, IX. 256. 
