220 ^^ MURIATIC AND OXIMUEIATIC ACID. 



Spec. grav. of to the article ** Muriatic Acid" in vol. I, p. 446, where I 

 iruriatic aciii fji^^j i^^g weight Stated with respect to common air, as 1*73 to 

 1*00— Considering this therefore as Dr. Henry's own opi- 

 ' nion of its real weight, I assumed it as one basis for my 

 calculation. I am »uare that Mr. Davy, at p. 245, Phil. 

 Trans, for 1810, states the weij;ht of 100 cubic inches of 

 muriatic acid gas, at 39 grs. which gives its specific gravity 

 as 1*258 — and from the acknowledged accuracy of that 

 gentleman's experiments, I am inclined, on farther consi- 

 deration, to adopt his estimate, which also nearly aj^rees with 

 Spec.grav. of ^^'^i of Biot and Giiy-Lussac. With respect to the specific 

 oxigengas. gravity which I have assigned to oxigcn [l'12o] I acknow- 

 ledge an errour 1 have inadvertently fallen into, from not 

 remarking, that Mr. Davy's estimate of the weight of 100 

 cubic inphes of that gas, viz. 35"06 (vide Henry's Elenjents, 

 p. 178, Tol. I,) IS given at the temperature of 55% and that 

 consequently at 6o° it would be but 34.7 (as stated indeed 

 ^ iti the same paragraph), which gives its specific gravity, 



i'lig"; and also I will farther allow, that (leaving ri 25 for 

 oxigen) the number 90*72 should be 92*4. I must apolo- 

 gize to you. Sir, as well as to Mr, Dalton, for these inaccu- 

 racies; which arose from the necessity I was under of put- 

 ting my thoughts to paper in greater haste than I should 

 have done, had not other avocations claimed the time I would 

 gladly have spent in their revisal. As to my mode of rnl- 

 Modeofcal- culation, it is simply this: — Mr, Chenivix's estimate of 

 cu}ation. ^]^g composition of oximuriatic gas, (viz. 77*5 muriatic acid 



+ 22-5, oxigen) is given by weigfd. To reduce these to 

 proportionate quantities by measure, I divide the specific 

 gravity of the heavier gas by that of the light er* I multiply 

 the quantity oi the lighter by the quotient, and add the 

 sum to the quantity of the heavier gas. — And I then say, 

 as the sums so added, are to either of them, so is 100 to 

 the proportional quantity^ required. Thus 7-7-—— 1'537 X 

 22-5 =34-5 4- 77*5 =z 112. Then 1 12 : 34-5 : : 100 : 30-8 

 rz the quantity of oxigen in 100 parts of oximuriatic gas, 

 on the old hypothesis, by measure. Consequently this 

 quantity would take twice its bulk of hidrogen, and the 

 whole that would disappear on detonation, would be 30*8 X 

 Tfae corrected ^ =: 924. If these data be true, my inaccuracies have 



been 



