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XXXV. On some of the Products of the Pestructive Distillation of Boghead Coal. — Part II. 
By C. Geeville Williams, Lecturer on Chemistry in the Normal College, Swansea. 
Received December 17, 1857, — Read January 14, 1858. 
The first part of this paper contained the results of the examination of those hydro- 
carbons found in the distillate from the Torbane-hill mineral which were remarkable 
for then’ resistance to the action of monohydrated nitric and sulphuric acids. It was 
shown that, when in a state of purity, they possessed the composition, boiling-point, and 
density in the fimd and gaseous states, of the radicals of the ethylic class of alcohols. 
The present communication enters on the study of a group of substances as distinguished 
by the mobility, as the former are by the fixity of their hydrogen atoms. The exami- 
nation of them has involved more labour than was experienced with their companion 
hydrocarbons ; and the quantities obtained being necessarily small, even when worldng 
on a considerable scale, it has been impossible, at present, to do more than determine 
their constitution. The study of their combinations and decompositions is therefore 
necessarily deferred. 
Up to the present time we have been unacquainted with methods for the proximate 
analysis of complex mixtures such as that under study. It was necessary, therefore, to 
dedse some plan for the purpose. The presence of benzole and its homologues was 
almost a matter of certainty, as they appear to be formed in all processes where coaly 
or bituminous matters are subjected to destructive distillation. In order to separate 
the hydrocarbons, the following method was adopted. Four ounces of bromine being 
placed in a large and well-stoppered flask, about eight volumes of water were added. 
The naphtha boiling in the fourteenth rectification between 71° and 77° Centigrade, 
was then added in very small portions, the whole being violently agitated after each 
addition. As the bromine, from its superior density, lay at the bottom of the water 
and the naphtha at the top, it will be seen that combination could not take place until 
the flask was shaken, at which time they united with a sharp hissing sound and a rise of 
temperature. The entu’e quantity of naphtha was absorbed by the bromine, forming a 
dense oil, becoming paler and at last colourless as the hydrocarbon increased in quan- 
tity. To ensure a definite product more bromine was used, so as to obtain a red oil, the 
excess being afterwards removed by agitation with mercury. During the process some 
substance is generated, acting powerfully on the eyes and causing a flow of tears ; it is 
always present in the brominated oil, even when every trace of free bromine is removed. 
If the brominated oil be kept for some time in contact with water, it will be found that 
a third layer will make its appearance beneath the oil ; this will be described hereafter. 
MDCCCLVII, 5 D 
