Miscellanies. 207 



acid, which is easily isolated from the first by successive solutions and 

 crystallizations, on account of their very different solubility. M. Baup 

 names this acid citricic, reserving citrihic for the pyrocitric acid of Las- 

 saigne. 



It is inodorous, and possesses a strongly acid taste. Its crystals are 

 rhomboidal octahedrons, and its primitive form the right rhomboid al 

 prism. At 10° C. it is soluble in 17 parts of water ; at 20° in 13 parts. 

 Its solubility augments with the temperature. At 15° it dissolves in four 

 parts of alcohol at 0.88 ; it is also soluble in ether. A heat of 100° or 

 even 120° C. separates no water of crystallization. At 161° C. it is a 

 colorless liquid which crystallizes on cooling. In the crystalline state it 

 may be represented by formula C ^ • H^ O* . When it combines with bases 

 it loses one atom of water and becomes C" H* O^. This acid is there- 

 fore isomeric with that of the citribic acid of Dumas. 



Citricic acid precipitates the acetates and subacetates of lead, and com- 

 municates a reddish tint to the ferric salts. The citricates of potash and 

 soda are very deliquescent. In the neutral citricates as well as citribates 

 the oxygen of the base equals one third that of the acid. — L'Institut, 

 No. 167. 



4. On the non-existence of a compound of Platinum and Hydrogen, by M. 

 DoBEREiNER. — According to Berzelius, the black non-metallic substance 

 obtained by precipitating a compound of chlorid of platinum and iron, 

 and afterwards reducing by means of hydrogen gas, is a compound of 

 hydrogen and platinum. Davy also supposed that a compound of these 

 two elements was formed by throwing an alloy of platinum and potassi- 

 um into water, by which the potassium was separated into black scales. 



Dobereiner has studied both these compounds with care, and finds that 

 they present the same action with hydrogen, (that is, they become red,) 

 as the compounds obtained in the moist way by means of alcohol, sugar, 

 or formic acid. Moreover, they oxidize formic and oxalic acids, producing 

 at the time carbonic acid, and acetify alcohol. His experiments therefore 

 demonstrate that all these properties proceed from oxygen gas, which is 

 mechanically condensed in this preparation of platinum, on account of 

 the strong affinity of powdered platinum for oxygen. — Ann. der Phys. und 

 Ch. 1835, No. 10.— L'Institut, No. 161. 



5. Sixth satellite of Saturn. — By a letter from Sir J. Herschel, from the 

 Cape of Good Hope, dated June 12, 1837, to a gentleman in London, it 

 appears that he has rediscovered the sixth satellite of Saturn, (the second 

 in order of the seven from the planet.) Since his father's observation no 

 one had been able to procure any decisive evidence of its existence, far- 

 ther than by his report. Sir J. H. had several good observations of it, 

 and has traced it round and round many revolutions. — Editor's corres- 

 pondence. 



