Intelligence and Miscellaneous Articles, 319 



is deposited on cooling in the form of scales : the solution in alcohol, 

 with the addition of animal charcoal, is to be repeated. 



Cantharidine thus obtained has the following properties : It is ino- 

 dorous ^ when heated to 400° Fahr. it melts ^ and if the heat be con- 

 tinued, it is converted into white vapours, which condense in small 

 crystals on the sides of the vessel. 



Concentrated and boiling sulphuric acid dissolves cantharidine j the 

 solution has a light brown colour : when diluted with water, it depo- 

 sits cantharidine in small needles. 



Boiling nitric acid dissolves it without any change of colour j the 

 solution deposits small crystals on cooling, and the same effect is 

 produced by muriatic acid. 



Potash and soda dissolve cantharidine ; and if concentrated acetic 

 acid be added to these solutions, the cantharidine is deposited in small 

 crystals. Ammonia has no action on cantharidine. 



Oil of turpentine, olive oil, and oil of sweet almonds dissolve can- 

 tharidine when hot, but it deposits on cooling. — Journal de Chimie 

 MMcale, Mars 1835. 



GALLIC ACID SPEEDILY PREPARED. 



According to Dobereiner, gallic acid may be prepared by mixing a 

 concentrated infusion of galls with acetic acid, in order to decompose 

 the gallate of lime ; it is then to be shaken for a few minutes with 

 aether, which takes up much gallic acid ; the aether is to be slowly 

 evaporated, and gallic acid is obtained in a very short time in small 

 colourless crystals.. — Ibid. 



PRESERVATION OF DELIQUESCENT SALTS. 



M. Druchar recommends that a few drops of oil of turpentine 

 should be put into the bottle, and when it is diffused the deliquescent 

 crystals should be introduced. — Ibid. 



COMPOSITION OF THE ATMOSPHERE. 



M. A. Chevallier is at present occupied with researches on the 

 composition of the atmosphere j he states the following as the results 

 already obtained : 



1st. In general, the air of Paris and of many other places contains 

 ammonia and organic matters in solution. 



2ndly. If the water deposited from air (dew) by cooling be exanjined, 

 it is found to contain ammonia and organic matters. 



3rdly. The quantity of ammonia contained in the air is often pretty 

 considerable. 



4thly. The presence of ammonia is easily explained, because this 

 gas is produced under many circumstances. 



5thly. The composition of atmospheric air may vary in certain lo- 

 calities, from a great number of particular circumstances, as the nature 

 of the combustible employed in great masses, the decomposition of 

 animal and vegetable matters, &c.&c. The air of London contains sul- 

 phurous acid, that of the sewers of Paris contains acetate and hydro- 

 sulphuret of ammonia j air taken from near the bassinsde Montfau^on 

 contains ammonia and its hydrosulphuret. — Journal de Pliarmacie, 

 Nov. 1834. 



