OF ARTS AND SCIENCES. 161 



From the sodic hydrate used for washing tlie crude furfurol could 

 be separated in small quantity an oil volatile with steam, and possessing 

 a strong odor like smoked fish. It had the general characters of a 

 phenol, but I have not as yet further identified it. Since a large 

 quantity of material has been accumulated in prejjaring the furfurol 

 necessary for the following researches, I hope before long to make 

 further study of the less volatile constituents which are present in 

 smaller quantity. 



Ptroxanthin. 



I have already mentioned the yellow flocculent precipitate, formed 

 by the action of alkalies upon the crude furfurol, which upon exam- 

 ination proved to consist chiefly of pyroxanthin. This substance 

 was discovered in 1835 by Dr. Scanlan, * of Dublin, in the residue 

 from the preparation of methyl alcohol from crude wood spirit by 

 means of lime. In 1836, it was further studied by Apjohn and Greg- 

 ory, t who deduced from their analyses the formula CjiIIigO^, although 

 they did not succeed iu confirming this formula by the preparation and 

 analysis of any of its derivatives. This formula was subsequently 

 changed to Cj^HgOo by Gmelin, J although this change was apparently 

 not based upon any further experimental work. Although I have 

 not as yet had any very considerable quantity of material at my com- 

 mand, I have studied some of its reactions and prepared two well- 

 marked bromine derivatives whose percentage composition necessitates 

 the adoption of the formula CjjHjgOg. 



In the method I have described for the purification of the crude 

 furfurol, after that portion which is volatile with steam has been dis- 

 tilled off, there remains a red viscous oil in the retort, which, on 

 cooling, partially solidifies. If this semi-solid mass is then treated 

 with small quantities of cold alcohol, the red oil, which results, in part 

 at least, from the action of the sodic hydrate upon the furfurol, dis- 

 solves, while the greater part of the pyroxanthin is left behind in 

 minute crystals. Occasionally, this viscous residue crystallizes only 

 after the addition of the alcohol and vigorous stirring. The pyro- 

 xanthin seems to be more neatly separated, if the furfurol is slightly 

 acidified with acetic acid after separating the alkaline solution before 

 distilling with steam. After the crystals have been well washed with 



* Phil. Mag., [3] xli. 395. 



t Koyal Irish Acad. Proc, 1836, xxxiii. Ann. Chem. u. Pharm., xxi. 143. 



t Gmelin's Handbuch, vii. 157. 



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