1821.] Mr. Phillips's Reply to Dr. Hope. 31 



the gas evolved being condensed by 12 parts of water. To this 

 process I objected that as muriate of ammonia is decomposable 

 by little more than half its weight of lime, that one and a half its 

 weight is uselessly and inconveniently large, I objected also that 

 the operation ot mixing lime and muriate of ammonia was 

 extremely pungent, and that the large quantity of lime delayed 

 the operation of getting the ingredients into the retort I 

 objected also, that as the retort was ordered to be made red-hot 

 that it usually broke in the operation. In this I find I committed 

 an error, and I am afraid that it arose from confounding V0U r 

 process with that of the London Pharmacopoeia of 18U9 1 

 must, however, confess that 1 cannot find much real difference 

 in the d.rections. If iron be made red hot, 1 think it would be 

 difficult to determine that the sand placed upon it, and the retort 

 also placed in the sand, are far from possessing an equal temper 

 ature ; but you tell me, that " as much of the heat is carried off 

 by the gas, the temperature of the mixture is in every stao- e verv 

 far d.stant from the point of incandescence." By the heal beino- 

 carned off by the gas, I conclude that you mean it is rendered la* 

 tent,but for two reasons I do not see how this can happen • the first 

 is, that without the application of any heat whatever, so much am 

 . momacal gas is evolved as to create the pungency of which I com 

 plain from the mere mixture of the lime and muriate of ammonia • 

 and secondly, the ammonia during condensation scarcely raises 

 the temperature of the water. If then aunnoniacal gas may be 

 evolved without the application of heat, I do not see how it can 

 carry any oft when given out during its operation; and I think 

 that during condensation such heat would be again given out • 

 but this as 1 have just stated, does not appear to be the case ' 

 In order to determine whether any greater product is obtain- 

 able by using so large a proportion of lime as you order, I twice 

 prepared the solution according to your directions. The mean 

 specfic gravity of the aqua ammonia, obtained was 0-936, being 

 ra her stronger than you state: the mean quantity of ammonif 

 es .mated by Sir H Davy's table of the strength of ammomacal 

 solutions amounted to 40-5. I then prepared aqua ammonS 

 nsmgonly two-thirds of the quantity of lime ordered in your 

 Pharmacopoeia, and this quantity, i think, needlessly laTe 



obtn LTl^TV - e , T 8tren S th of th « products with thofe 

 obtained by the Edinburgh process, I found it to be exactly 40 

 the ai ft eren b onl . 5j whjch bg attHb C u ^ 



the error of operating ; for I found greater differences than thU 

 between the values of the two prod ucts in both eases No w even 



important, because, when slaked, ft is extremely bulky, and the™ 

 lore, requires large retorts, which increase the expense e necia lv 



t?m e r 01d, ;>; t0 'T xp f r ce ' the retoits br - k ^25S£ 



times and the value of them is at least eight times greater han 

 that of the substances operated upon ; it is on this account that 



