164 THE CANADIAN NATURALIST. 



Valuable papers on alizarine have been published by Perkin and 

 Scliunk. The latter has described a new acid — the anthraflaric 

 — which is formed in the artificial preparation of alizarine. 

 Madder contains another colouring principle, purpurine, which, 

 like alizarine, yields anthracene when acted on by reducing agents, 

 and has also been prepared artificially. These colouring princi- 

 ples may be distinguished from one another, as Stokes has shown, 

 by their absorption bands ; and Perkin has lately confirmed by 

 this optical test the interesting observation of Schunk that fin- 

 ished madder prints contain nothing but pure alizarine in combi- 

 nation with the mordaunt employed. Hofmann has achieved 

 another triumph in a department of chemistry which he has 

 made peculiarly his own. In 1857, he showed that alcohol bases, 

 analogous to those derived from ammonia, could be obtained by 

 replacement from phosphuretted hydrogen, but he failed in his 

 attempts to prepare the two lower derivatives. These missing 

 links he has now supplied, and has thus established a complete 

 parallelism between the derivatives of ammonia and of phosphu- 

 retted hydrogen. The same able chemist has lately described the 

 aromatic cyanates, of which one only — the phenylic cyanate — 

 was previously known, having been discovered about twenty years 

 ago by Hofmann himself. He now prepares this compound by 

 the action of phosphoric anhydride on phenylurethane, and by a 

 similar method he has obtained the tolylic, xylylic, and napthylic 

 cyanates. Stenhouse had observed many years ago that, when 

 aniline is added to furfurol, the mixture becomes rose-red, and 

 communicates a fugitive red stain to the skin, and also to linen 

 and silk. He has lately resumed the investigation of this sub- 

 ject, and has obtained two new bases — furfuraniline and furfur- 

 tolnidine — which like rosaniline, form beautifully coloured salts, 

 although the bases themselves are nearly colourless, or of a 

 pale brown colour. The interesting work of Dewar on the oxi- 

 dation of picoline must not be passed over without notice. By 

 the action of the permanganate of potassium on that bod^?, he 

 has obtained a new acid, which bears the same relation to pyri- 

 dine that phthalic acid does to benzol. Thorpe and Young have 

 published a preliminary notice of some results of great promise 

 which they have obtained by exposing paraffin to a high temper- 

 ature in closed vessels. By this treatment it is almost completely 

 resolved into liquid hydrocarbons whose boiling points range from 

 18° C. to 300° C. Those boiling under 100° have been exam- 

 ined, and consist chiefly of olefines. In connection with this 



