14i Analt/ses of Books. [Aug. 



trough, under an inverted graduated jar, filled with water. As 

 soon as the paper round the sal-ammoniac was sufficiently- 

 softened to allow the dichloride to come in contact with the salt, 

 an effervescence took place, and azotic gas was disengaged. 

 This is just the effect always produced when chlorine and am- 

 moniacal gas come in contact. The lime which was in excess 

 in the salt decomposed the sal-ammoniac ; and the ammonia, as 

 it was evolved, came in contact with chlorine, and was decom- 



Eosed ; the hydrooen uniting with the chlorine, and the azote 

 eing disengaged in the gaseous state. The action is so violent, 

 if the dry sal-ammoniac be dropped at once into the retort, that 

 it is difficult to collect the whole gas ; but when the salt is 

 wrapped in paper, the action is slow, and the gas may be all 

 collected with the greatest facihty. The azotic gas obtained in 

 this process was 11*7 cubic inches, at the temperature of 47°, 

 and when the barometer stood at 29*93 inches. This is equiva- 

 lent to 1 1*853 cubic inches of dry gas, of the temperature 60°, 

 and under a pressure of 30 inches mercury. 

 - " This constitutes the whole amount of the azotic gas in 4'25 

 grains of ammonia, the quantity contained in 13*5 grains of dry 

 sal-ammoniac. Now, 11*853 cubic inches of azotic gas weign 

 3*5147 grains. Hence it follows, that the weight of the other 

 constituent, the hydrogen, is 0*7353 grain. Consequently, am- 

 monia is composed of 



Azote 1*7573 or 1 volume 



Hydrogen 0*3676 2*94 



2-1250 



The small excess of azote in this experiment was owing to a 

 small admixture of common air with the azote, in consequence 

 of the gas standing 24 hours over the water. 



" The experiment was repeated seven times, in various ways, 

 and the mean of the whole came exceedingly near 1 1*8 cubic 

 inches of dry azotic gas from 13*5 grains of sal-ammoniac. This 

 weighs 3*4993 grains, giving.us the compositioa of ammonia as 

 follows: _rilK ;t. U>- , /•*;?/. .- oi i 



Azote . .^•,. <jrfkii5^*, .1*74965 or I volume 

 Ilydrogenr. u^hsw «v w . 0*37535 3*0028 



2*12500, ,, 



This analytical result! of . direct experiment' cofties »witHin ^less 

 than -xToo^th part of the theoretical estimate ;> aWdly'taJeett' toge- 

 ther with the preceding facts, can leav6 no doubtw'iHfe^hSfo- 

 sition of ammonia.'' - ' !> , .lii.j. hBN bnx5 ,*ihl 



At p. 150, in treating of the <kompoiind»<6f»<tMirb^flmtf^ b^^S> 

 gen, a statement occurs which both surprifeed and atWueed'uS. 

 The author mentions his belief Uiat no fewer than five diffetent 



