CELESTINE DEPOSITS OF THE BRISTOL DISTRICT. 165 
dioxide into the solution. In this reaction sulphuretted 
hydrogen is evolved, and being a valuable bye-product is 
collected in gasometers and burnt to sulphur dioxide which is 
used for the manufacture of sulphuric acid. 
Both the above methods yield strontium carbonate which 
is the most convenient starting-point for the preparation of 
the strontium compounds. Dissolved in acids it gives the 
corresponding salts, and is converted into the oxide by the 
action of heat. The hydrate obtained by dissolving this oxide 
in water and recrystaUization is used in very large amounts 
in the beetroot sugar industry. 
Molasses, a product of this industry, contains about 50 per 
cent, of sugar which is so impure that the sugar cannot be 
obtained from it by recrystaUization from water. It is used 
either for the preparation of rum, spirits of wine, or as food 
for cattle, but sugar may be extracted from it by means of 
strontium hydrate, which possesses the power of forming an 
insoluble compound with it that may be washed, filtered off 
from soluble matter, and decomposed by a current of carbon 
dioxide into carbonate of strontium and a sugar sufficiently 
pure to recrystalHze from water. 
This industry accounts for nearly the whole of the celestine 
mined at the present day, the amount used in the manufacture 
of fireworks and for scientific work being extremely small. 
