It is highly probable that if facilities be available for the re- 
moval of the end products of the reaction as they are formed, the 
solubility of the mineral would be considerably increased. 
In order to ascertain the solubility of alunite in lime with mini- 
mum amount of water, an experiment was carried out on 11b. (453 
grams) of alunite containing K 2 0, 7.S4 per cent.; Na 2 0, 2.72 per 
cent., crushed to pass a 10-mesh screen, mixed with % lb* (226 
grams) lime (CaO) and one gallon of water. It was allowed to 
stand for two days with occasional stirring and then filtered, the 
solution being evaporated to small bulk to remove the calcium sul- 
phate, again filtered and evaporated to dryness. The yield of crude 
potassium and sodium sulphates was 0.12051bs. (54.6 grams), equal 
to 70.1 per cent, of the potash and soda present in the ore. 
These results are of the greatest value in the utilisation of alu- 
nite as they indicate a cheap and ready method for converting the 
potash of the mineral into a readily available form, and T commend 
them to the serious consideration of agricultural chemists. 
SOLUBILITY IN CALCIUM CARBONATE SOLUTION. 
No record could be found of the effect of calcium carbonate on 
alunite. Owing to the highly satisfactory results obtained by the 
treatment with caustic lime solutions and also to the fact of the gen- 
eral use of carbonate of lime in agriculture, it was considered ad- 
visable to carry out a systematic series of tests with solutions con- 
taining calcium carbonate. The solubility of calcium carbonate in 
water is very low, but calcium carbonate in solution hydrolyses, 
forming calcium hydrate and calcium bicarbonate, both of which 
have a greater solubility in water than normal calcium carbonate, 
but are included in the solubility, viz., 0.013 grams per litre, of 
UaUO., in water. 
r fhe mineral in each case was placed in flasks with 400 cc. of 
water and 0.710 gms. of pure precipitated calcium carbonate added; 
the flasks were stoppered with waxed corks and kept closed during 
