380 Miscellanies. 



15. Vegetable Cliemistry. — Animal and vegetable chemistry afford 

 to the man of Science, the most astonishing field of contemplation. 

 He sees all the varieties of vegetable nature reducible to four elements, 

 and animal products in general made up of the same number, and yet 

 there is no end to their combinations, and none can tell the limits 

 within which the changes of nature wrought through the aid of such 

 scanty materials must be confined. Yet this beautiful simplicity has 

 hitherto rendered the study of her combinations perplexing, and we 

 have been imable often to discover such differences in atomic consti- 

 tutions as at all to account for the diversities in external appearances 

 and character of many vegetable and animal substances. But our 

 knowledge is enlarging, and, as the resources of organic analysis be- 

 come greater, it is to be hoped that we shall by degrees attain, if not 

 to a complete, at least to a much less imperfect view of the chemical 

 constitution of organized bodies than we can yet boast of. — Idem. 



16. Camphor. — Libri has mentioned a curious circumstance regard- 

 ing odoriferous bodies such as camphor ; that if they be exposed to a 

 current of electricity for a considerable time their smell diminishes, 

 and at last disappears entirely. After a lapse of time, camphor again 

 recovers the power of emitting odors. — Idem. 



17. Geology. — In connection with Geology, we shall advert to C. 

 G. Gmelin's elegant examination of Clinkstone. He has found that 

 this volcanic rock is an aggregate of mesotype and felspar. He shows 

 this in a very interesting way. He treats the mineral with muriatic 

 acid, and separates the dissolved portion, after which the silica of the 

 decomposed part is dissolved out by boiling with carbonate of potash. 

 In the mesotype, a portion of the soda is compensated by potash and 

 lime, and a part of the alumina by peroxide of iron and manganese, 

 and in like manner, in the felspar, a part of the potash is compensated 

 by soda and lime, and of the alumina by oxides of iron and manganese. 

 In this investigation the water in the mesotype was found to be less 

 than in the same substance when crystalized. The water might pos- 

 sibly be merely hydroscopic, as its quantity in the mineral vai-ied from 

 0,633 to 3.19 per cent. It is probable that the application of this 

 principle to other rocks might be productive of very interesting results, 

 and might throw light upon geological formations, which we shall 

 seek in vain from the analysis of specimens of rocks in the aggrega- 

 ted state. — Idem. 



IS. Populine. — It was announced to the French Academy on the 

 6th of September last, by Gay-Lussac thatM. Braconnot, of Nancy, 



