Intellige7ice and Miscellaneous Articles. 



result might be foreseen ; for when a mixture of pectase and pectin 

 is put into a bottle, and it is hermetically sealed, the pectin is suc- 

 cessively converted into pectosic, pectic, parapectic, and metapectic 

 acids, without forming any secondary product. 



The capacities of saturation given in the following table prove that 

 the acidity of the gelatinous bodies increases in proportion as their 

 equivalent diminishes. Thus parapectin, the equivalent of which is 

 very heavy, forms a neutral salt with lead which contains 10 per 

 cent, of oxide, and does not redden tincture of litmus ; and meta- 

 pectic acid, the equivalent of which is very light, produces a salt of 

 lead which contains 67 of oxide, and its acidity resembles that of 

 malic or citric acid. 



Names of the gela- Composition of the Composition of the 



tinous substances. gelatinous substances. salts of lead. 



Pectose 



Pectin C6+ H« O^e, 8H0 



Parapectin C^" H^o O^^ 8H0 C^ H^o 0^\ 7H0, PbO 



Metapectin ...... C^*W 0^\ 8H0 C«i H<o O^^ 6H0 2PbO 



Pectosic acid .... C32 H"-" O^^, 3H0 C^"- W O^s, HO, 2PbO 



Pectic acid C^^ H^o O^s, 2H0 C^^ W° 0'«, 2PbO 



Parapectic acid . . C^-^ H^s O^i, 2H0 C^* H'^ O"-', 2PbO 



Metapectic acid . . C^ H^ 0^, 2H0 C^ H^ O?, 2PbO 



M. Fremy states that the formula of pectic acid, which he has 

 here adopted, gives in 100 parts exactly the same quantities as de- 

 termined by M. Regnault, and as published by himself in his first 

 memoir on gelatinous bodies. 



The author concludes that he has succeeded in proving that vege- 

 tables contain a neutral insoluble substance, which is convertible 

 during vegetation into an energetic acid. — Comptes Rendus, Juin 14, 

 1847. 



PREPARATION OF PROTOXIDE OF TIN. 



M. Roth gives the following process for preparing the red prot- 

 oxide of tin : — The white hydrate is to be prepared, and after being 

 well-washed it is to be digested at 133" F. in a solution of prot- 

 acetate of tin, with a slight excess of acid, and of specific gravity 

 about r06. The protoxide is then converted into hard heavy grains, 

 wliich yield a greenish-brown powder ; these grains inflame when 

 heated, and readily blacken in the sunshine. They behave with 

 reagents like common protoxide. — Journ. de Ph. ct de Ch., Aout 

 1847. 



iON THE PRESENCE OF ARSENIC, COPPER AND TIN, IN THE 

 MINERAL WATERS OF BAVARIA. 



According to the experiments of M. Buchner, Jun., the brown- 

 ish-yellow ochrey deposit of the springs of Ragoczy and of Pandour, 

 at Kissingen, contain only doubtful traces of copper ; but they con- 



