102 Experiments for ascertaining the Existenee of- 



drams of muriatic acid of the specific gravity of 1 120, and 

 two. ounccsof pure nitric acid of leio, and by continued 

 sinnnering were evaporated to dryness. From the begin- 

 ning to the end of the operation, vapours of oxygenated 

 muriatic acid and of nitrous gas were disengaged : the former 

 exactly in the same manner as when muriatic acid is poured 

 over oxide of cobalt not carbonated nor heated to redness. 

 Three drams of muriatic acid and two ounces of nitric acid 

 were repeatedly poured over the oxide of cobalt, and distilled 

 todn,-ness. The same phscnomena took place. The acid so- 

 lution of cobalt evaporated to dryness was dissolved in four 

 Ounces of water, filtered, and decomposed by pure carbonate 

 ftf ammonia. After the decomposition as much ammonia 

 as was necessary for this purpose was then added, and the 

 whole was shaken for halt an hour in a gentle heat. The 

 solution had a blue appearance. It was then freed from the 

 Tindispolvcd residuum bv the lilter and edulcoration, and, 

 being evaporated to dryness, three grains of oxide of cobalt 

 of a greenish colour were separated. The precipitate, when 

 dried in a gentle heat, weighed, without reckoning the small 

 (Quantity separated during the c\'aporation, about as much 

 •as the oxide of cobalt employed, and had a violet colour. 

 The saline mass, when again dissolved and filtered, was of 

 a pale green colour, had a sharp metallic taste, and exhi- 

 bited the following phapnomena : 



1st, It gave a red colour to litmus paper. 2d, It contained 

 ammonia, nitrous acid, and a little cobalt ; for when a little 

 of it was decomposed in a red heat and evaporated to drv- 

 ncss, which was accompanied with crackling and inflam- 

 mation, nothing remained but two or three grains of black 

 oxide of cobalt, without a trace of acid. 3d, It produced no 

 • lurbid appearance in acetile of lead : 4th, Nor in nitrate of 

 yilver. 5th, It rendered annnoniate of copper exceedingly 

 turbid ; but bv the addition of more solution it was redis- 

 .^olved and became perfectly clear; which proves that the 

 precipitate had been effected by the free acid of the com- 

 tiination. 6th, It communicated scarcely any turbid appear- 

 ance to sulphate of copper : 7th, Nor did it disturb in any 

 manner nitrate of mercury prepared without heat. 8th, It 

 produced no change in a concentrated solution of tnuriaic 

 of barytcs, 



from this experiment, and the phapnomena it exhibited, 

 it appears pro^■ed beyond a doubt, 1st, That by the processes 

 described all- the muriatic acid had been driven off'; 2d, That 

 no more ar.-:crical acid was present: and, 3d, That no co- 

 baitic acid can be formed by this process, 



Nqw, 



