474 
DR. JOHN STENHOUSE ON THE OILS PRODUCED BY THE ACTION 
Pyrofucusol. 
When thiofurfurol is destructively distilled it is decomposed with the formation of 
a curious substance called pyrofurfurol, which crystallizes in long- needles and contains 
no sulphur. M. Cahours’s formula for it is Cjg Hg O4. Thiofucusol, when distilled, 
yields a similar compound, which I shall call pyrofucusol. It also crystallizes in long- 
needles, and has probably the same composition as pyrofurfurol, though from the very 
small quantity at my disposal I was unable to ascertain this by analysis. 
Fucuslne. 
When pure fucusamide, which should be nearly colourless, having only a slightly 
yellowish shade, is boiled for 20 minutes or half an hour with moderately strong soda 
or potash lye, no ammonia is evolved, and the amide is changed into a light brownish- 
coloured oil, which solidifies on the cooling of the liquid. It consists of a salifiable 
base, which I shall call fucusine, combined with a quantity of a brownish resin. This 
crude fucusine, when separated from the lye in which it has been boiled, is always soft, 
even at low temperatures, and does not exhibit the least approach to crystallization. 
At the temperature of 10° C. it is exceedingly tenacious, and may be easily drawn into 
threads, which resemble those of half-dried molasses. If we attempt to separate 
fucusine from adhering resin by boiling it with water and filtering, we find, on the 
cooling of the solution, that a yellowish amorphous resin is deposited on the sides and 
bottom of the vessel. This method therefore, by which furfurine is so readily purified 
and obtained in a crystalline state, does not at all succeed with fucusine. Though I 
made many attempts, I was equally unsuccessful in crystallizing crude fucusine either 
from alcoholic or etherial solutions. If the fucusamide which has been employed in 
the preparation of fucusine is so impure as to have a brownish colour, it is next to im- 
possible to extract any pure fucusine from it. In this repect therefore fucusine differs 
very considerably from furfurine, which, even when very impure, solidifies on cooling 
to a hard crystalline mass ; and if it is digested with a little animal charcoal and 
crystallized two or three times out of boiling water, it is deposited on the cooling of 
its solution in long slender colourless needles. Fucusine, on the other hand, so long 
as it is mixed with a little resinous matter, does not crystallize at all, and even when 
perfectly pure does not crystallize nearly so readily as the analogous base. 
The way in which I succeeded in purifying fucusine, was by preparing some of its 
salts, which crystallize pretty readily, even from impure solutions. The salt best 
adapted for this purpose is the nitrate, and the mode of proceeding was the following. 
The crude fucusine was digested with a very slight excess of dilute nitric acid at a 
heat little higher than was necessary to melt it. The crude fucusine was constantly 
stirred with a spatula, so as to biing every portion of it into contact with the acid 
liquid. The mixture was then allowed to cool for a few minutes till the resinous 
matter had solidified, when the liquid portion was poured off into a second basin, 
where it soon deposited a quantity of hard shining crystals. By repeatedly digesting 
