Chemistry. 261 
the chloride of sodium and chloride of lithium, with very satisfactory 
results; the latter salt being dissolved in this mixture. L. 8. 
14. On the estimation of Fluorine; by F. Wouter, (Chem. Gaz., 
1845, p. 403, from Pogg. Annalen, 1845.)—The weighed substance is 
intimately mixed with pure:silica, unless it already contains this ingre- 
dient; the mixture is placed in a small flask, which can be weighed ; 
very concentrated sulphuric acid, which has been boiled, is added, and 
the flask quickly closed with a cork, through which a small tube passes, 
that is filled with fused chloride of calcium, and drawn out to a point. 
The whole apparatus is now weighed, and then exposed to a proper 
heat as long as gaseous fluoride of silicon is evolved. The last por- 
tions are removed by exhaustion under the receiver of an air-pump. 
The loss in weight which it experiences is fluoride of silicon, from which 
the amount of fluorine is calculated. 1-395 parts of fluoride of silicon 
are formed for each part of fluorine. To test this method, the author - 
estimated the amount of fluorine in fluor spar, and the results were 
accurate to the first decimal place. Care must be taken that no car- 
bonates are present. J.L.S 
15. Sulphurous Ether ; by MM. Esenman and Bouquet, (Comptes 
Rendus, May, 1845.)—Sulphurous ether is formed by adding absolute 
alcohol by degrees to the protochloride of sulphur, until all action 
ceases; then distill the mixture—the first product that passes over is 
alcohol, acidulated by hydrochloric acid; but when the temperature of 
the liquid reaches 300°, the product in question begins to come over, 
and must be collected separately. It must be rectified until its boiling 
point remains constant. It is colorless, possessing an odor somewhat 
like mint; its taste is first cooling, then burning; it boils at 322° F.— 
dissolves in alcohol and ether, and is heavier than water, its density 
being 1-085. Composition SO? C+ H® O. J. L. 8. 
16. Production of Diaphanous Quartz and Hydrophane; by M. 
Esstman, (Comptes Rendus, August, 1845, p. 502.—When either of 
the two silicic ethers (see Am. Jour. Sci., July, 1845, p. 195) is ex- 
posed to the prolonged action of a moist atmosphere, the liquid solidifies 
to a transparent mass, which ultimately becomes hard, and has the 
lustre, fracture, and transparency of the most limpid rock crystal ; its 
density is 1:77. It is a hydrate, having for its formula (SiO)? HO. 
One condition necessary to produce this substance, is to allow the 
moist air to enter by a very small opening, to produce a very slow con- 
traction and solidification. If the silicic ether employed retains a little 
chloride of silicon, which happens when an excess of alcohol has not 
been employed in the preparation of the ether, the quartz formed as- 
sumes the appearance of hydrophane, instead of being diaphanous: 
the greater the impurity, the greater the opacity. This hydrophane 
