— 168 — 

 CH 2 CH — CH 2 CH 2 — CH — CH 2 



H 3 C-C-CH 3 



H 3 C-C-CH 3 



CH 2 — C CO CH=C CHO 



CH 3 CH 3 



Camphor Campholenic aldehyde. 



This surmise was confirmed by hydrolysis of the hydroxamic acid, in 

 the course of which dihydrocampholenolactone and what appeared to be 

 a mixture of the two camphenolenic acids were obtained. In addition to 

 camphenolenic aldehyde ['a ketone of the empirical structure of camphor 

 had been formed, which was separated from the camphor by means of 

 the more easily soluble semicarbazone (m. p. 151 to 152°). When oxidised 

 with permanganate it yielded a dibasic acid Ci Hi 6 O 4 , m. p. 133 to 134°. 

 The authors were unable to identify the ketone, but they intend to 

 continue their investigations with a larger quantity of the original material. 



Fenchone, on being exposed to light, behaved altogether different 

 from camphor. Besides traces of formic acid, there had accumulated 

 a gas which proved to be carbon monoxide. In addition to this a hydrate 

 of fenchone, Ci Hi 8 O 2 , had been formed which, judging from its chemical 

 characteristics, was a glycol. It occurred in leaflets, m. p. 138 to 139°, 

 reacted with phenyHsocyanate, giving rise to an ether of di-phenyl iso- 

 cyanate which melted (under decomposition) at 206°, and yielded a di- 

 benzoyl-ether, m. p. 66°. Besides these a small quantity of a liquid boiling 

 between 175 and 180° and unstable towards oxidising agents had been 

 formed, but the authors have not yet examined this, because they were 

 unable to separate it from the fenchone which was admixed with it. 

 Finally Ciamician and Silber describe a few experiments they have made 

 with the higher ketones with ramified chains, for instance with methyl- 

 heptenone, which, however, remained completely unaffected by light. 



PharmacO'physiological Notes. 



D. Gilmour 1 ) has published an article on the antiseptic and other 

 properties of essential oils employed in dental practice. He discusses 

 the various oils according to their degree of antiseptic action, giving the 

 first place to cassia oil, which, however, has the drawback of irritating 

 the softer tissues, and is therefore very liable to cause inflammation; 

 it is also said to cause a discoloration of the teeth which is difficult to 

 remove. It should never be used in the treatment of the root canals of 

 teeth, but it renders excellent services in acute cases of pyorrhoea, where 

 the pockets are deep and pus is considerable. Ceylon cinnamon oil has 

 similar properties, but in a less degree. Next to these two oils stands oil 



x ) British Dental Journal; quoted from Pharmaceutical Journal 84 (1910), 644. For the 

 bactericidal action of essential oils also compare Report October 1906, 155; April 1908, 174. 





