Miscellanies. 215 



grouping of species into a genus, or genera into an order, is not by defi- 

 nite rules, but by a latent talent of appreciation — a sort of classifying 

 instinct. These are purists. Naumann in 1828 adopted a mixed sys- 

 tem, the chemical and natural history. He made haloides, salts of 

 oxides, unmetallic and metallic, and these hydrous and anhydrous, which 

 divisions give good natural groups. 



The siliceous minerals are the most difficult to arrange. He calls them 

 silicides — metallic and unmetallic, amphoteric — and again hydrous and 

 anhydrous. This is a good basis for future researches. Natural history 

 began to make its appearance in systems of chemistry. The combina- 

 tion of the chemical, crystallographical, and optical properties, into some 

 lofty generalizations, is probably a triumph reserved for future and distant 

 years ; for a complete geological survey of the whole earth is requisite as 

 a foundation for sound theory. 



16. Atomic Weights of Elements. — MM. Marchand and Erdmann are 

 at present engaged in a series of researches, which seem to prove that 

 Prout's idea, that all atomic weights are multiples of that of hydrogen, is 

 correct. They have as yet examined only the following bodies : 



Oxygen =100. . . 8 Calcium = 250 . . 20 



Hydrogen = 12.5 . . 1 Chlorine = 450 . . 36 



Carbon =75. . . 6 Silver =1250 . .100 



Nitrogen = 175. . . 14 Lead = 1300 . . 104 



Phil. Blag. Nov. 1842. 



17. Sugar in the Stalks of Maize. — Dr. Pallas, principal physician of 

 the military hospital of St. Omers, addressed to the French Academy of 

 Science during the past summer a memoir, in which he attempts to es- 

 tablish the following propositions — viz. 1st, that the stems of Indian corn 

 contain little or no sugar before flowering: 2d, that just at the epoch of 

 flowering only a mere trace of sugar can be extracted from them : 3d } 

 that the same stems, at from twenty to twenty five days after flowering, 

 while the grain is yet milky, contain one per cent, of crystallizable sugar : 

 4th, that still later, when the grain is perfectly ripe, the stems yield two 

 per cent, of coarse sugar, besides four per cent, of rich molasses. The 

 commission to whom this memoir was referred, (M. Biot, reporter,) how- 

 ever, very properly discredit these results, so contradictory not only to 

 our theoretical views, but also to all former observations ; as, for example, 

 those of Prof. Burger, who affirms that the sugar is most abundant in the 

 juice of the stem of maize immediately after the expansion of the flow- 

 ers, and that it diminishes as the grain is matured. The commission 

 states that the experiments of Dr Pallas on this subject were so loosely 

 conducted as to afford no results worthy of confidence. — Comptes Rendus, 

 August 29 5 1842. 



