16 
MR. BARLOW ON THE FORMATION AND 
bases, and the desired alkaloid has been obtained ; thds completing the inquiry which 
was commenced in the Royal College of Chemistry seven years ago. 
Preparation of Nitrocy mole. — It has been already stated that cymole, when heated 
in the usual way with concentrated nitric acid, produces substances differing greatly 
from the expected substitution-compound. To prevent this result, cymole and nitric 
acid, having been severally kept for some minutes in a freezing mixture of ice and 
salt, were cautiously mixed. The cold cymole was dropped from a pipette into the 
cold nitric acid. The mixture was at first brown, but, on continued addition of 
cymole, it gradually changed to green ; and when the substitution was complete, it 
assumed the consistency of cream. It was then projected into cold water, when the 
oily reddish-brown nitrocymole subsided to the bottom of the vessel. This was 
washed, first with water, and lastly, with a weak solution of carbonate of soda. 
Properties of Nitrocymole. — In the purest state in which it has yet been obtained, 
nitrocymole is a reddish-brown, transparent, oily fluid, of greater specific gravity than 
water, in which it is insoluble. It does not appear to be readily decomposed by con- 
tact of air. When distilled with water it produces a neutral oil, which floats on 
water, than which it is, consequently, of less specific gravity. It was found impos- 
sible to obtain the boiling-point either of nitrocymole or of this oily distillate, or to 
procure the body in a state fit for analysis. But subsequent examination of sub- 
stances derived from it removed all doubt that its composition is represented by the 
formula C20 H13NO4. 
Formation of Cymidine from Nitrocymole. — The process of Zinin, although suc- 
cessfully adopted in obtaining the lower bases of this series, was not found equally 
effectual when applied to this new substitution-product. A better result, though 
the quantity was still very scanty, was obtained by Bechamp’s modification of this 
method*. Nitrocymole was added to iron-filings brought to the consistency of paste 
by mixture with acetic acid, whereupon an immediate and considerable elevation of 
temperature indicated the commencement of chemical action. From the distillation 
of this mixture at a carefully-regulated heat a complicated product resulted. A con- 
siderable proportion of the distillate was found to be insoluble in hydrochloric acid. 
This was set aside for separate examination, the result of which will be stated at the 
close of this memoir. To the portion of the distillate which was soluble in hydro- 
chloric acid, soda was added in quantity just sufficient to neutralize the acid. The 
base (for which the name cymidine is suggested by obvious analogy) was then sepa- 
rated by ether and subsequently distilled. The same instability of composition, and 
tendency to oxidize, which have been noted as characterizing the hydrocarbon cymole, 
exist in this base, derived from it. Accordingly, it was found necessary to perform 
the distillation in an atmosphere of hydrogen, in order to prevent the conversion of 
the cymidine, at a high temperature, into a resin. 
* Annales de Chimie et de Physique, tome xlii. p. 193. 
