ON AQUA REGIA AND HYPOSULPHURIC ACID. 201 
rated on the water bath to dryness. The salt obtained is 
dissolved in twice its weight of water and crystallized. 
On mixing sulphate of ammonia and potash, sulphate of 
potash and chlorate of ammonia are formed, the former of 
which is not dissolved by the spirit. Since on careful evapo- 
ration of the aqueous mixture a small portion of the chlo- 
rate of ammonia is unavoidably decomposed, somewhat 
less carbonate of ammonia has been given in the above 
directions than required by theory. By the action of the 
carbonate of soda on the chlorate of ammonia, carbonate of 
soda is formed, and the residue is chlorate of soda. 
In the same manner chlorate of barytes maybe prepared 
with advantage, only in this case caustic barytes must be 
employed. A hot solution of barytes, prepared from crude 
materials (sulphuret of barium and oxide of copper, nitrate 
of barytes and iron-filings) answers very well; an excess of 
barytes does no harm, because it is converted into carbon- 
ate on evaporation; should, however, the residue still be 
alkaline, a current of carbonic acid may be passed through 
the solution. — Ibid from Ibid. 
ART. LV1II. — ON AQUA REGIA; ON HYPOSULPHURIC ACID AS 
A MEANS OF OXIDATION; ON THE CONSTITUTION OF THE 
SAME ACID, AND THE PART IT ACTS ON BEING PUT IN 
CONTACT WITH ORGANIC SUBSTANCES. 
By Dr. Kcene, Professor of Chemistr}' ; at Brussels. 
1. Aqua Regia may serve as one of the most powerful 
agents either for oxidising, acidulating, or dissolving a great 
number of simple and compound bodies. Important, how- 
ever, as this substance is, on account of the above uses, and 
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