il€4c KiCItEL AKD COBALT. 



on (he addition of fulpliuric acid, a difengagement of nitrous 



acid look place from the refidue obtained by evaporation, which 



wa«i alfo caufed by the addition of an alkaline h'xivium : Willi 



ammonia the fame effecls were produced which have been 



before mentioned. 



Sul|>hites and The refuits of tlie foregoing experiments aret — The ful- 



mo'nlacal'nkkel P^*''^^'' ^"^ nitrates of ammoniacal nickel feparaled from co- 



aJways contain bait ore, retain always fome cobalt in their compofition, and 



• it is impoiTible from the method of Hermftadt modified in the 



preceding manner, to obtain an oxide of nickel without a 



mixture of cobalt. 



The oxide of b. By partially decompofing the ammoniacal nitrate of co. 



Tn^tV fau aftir^ ^^'' ^^ evaporation, an oxide of nickel is obtained, very rich 



evaporatifjn con- in cobalt» which contains nitric acid; and the oxide of nickel 



urns very little vvhich remains undecompofed in this fait, retains a very fmall 



quantity of cobalt. 

 Br. Schnaubert's B- Do£tor Schnaubert has publiflied (in Tromfdorf's 

 method of ob- Journal of Pharmacy, vol. II. p. 66) a method of obtaining 

 ide of nickel, ^^^ oxide of nickel pure: Which confifts in dilTolving the 

 metal of nickel mixed with cobalt, or its oxide feparated from 

 other fubftances, in nitric acid, in precipitating it by the car- 

 bonate of polafli, and in heating it to a white heat, after walh- 

 ing and drying it. In this manner he always procured a yellow 

 oxide, on which he caufed very ftrong fulphuric acid to boil ; 

 which gave him a folulion of oxide of nickel of a grafs green, 

 while the oxide of cobalt appeared in the form of a yeHow 

 refidue. He proves the purity of the fulphate of nickel pre- 

 pared in this manner, by the property which ammonia has of 

 precipitating it of a bright green, and when added to excefs. 

 His tefl: or Its of re-diflblving it with a beautiful deep blue colour: but this 



puaty deftftivc. ** . ^ „ . , r , ^ . • i r 



argument appears niluthcient to thole who know that oxide or 

 nickel, although mixed with many hundredth parts of cobalt, 

 does not, however, experience any perceptible change in the 

 colour of its precipitates, nor in its ammoniacal folulions* 

 He has not men- Belidcs the omiffion of indicating the means by which he was 

 tioned his proof convinced that the oxide, which was the refidue of the fulr 



that the other ..... 



oxide obtained phuric acid folution, was really an oxide of cobalt, with the 

 was cobalt, vague prccept of iieating the oxide acquired, without the 

 gree of heat to '^^^ direction relative to the degree of the fire, and the un*- 

 be ufeJ, , certainty which he leaves of the degree of ftrength of the 



—nor the . /• i i • 



ftrength of the . fulpbur<«: 



fulphuric acid 

 en:plo)cd. 



