224 COMPOUND BLOWPIPE. 



(e.) These facts are best exhibited in public, by placing the pla- 

 tinum in a wine glass, but as it is liable to break from the sudden 

 heat, it is well to place a dish beneath. 



(/.) After precipitation of the orange precipitate, the yellow su- 

 pernatant fluid still contains platinum, as is indicated by muriate of 

 tin and hydriodic acid on evaporation, a solid is obtained, consisting 

 principally of the muriate of ammonia, and probably the foreign met- 

 als ; for on heating this residuum in a platinum crucible, as in the case 

 of the sponge, a little metallic matter is obtained, which, however, 

 does not ignite the hydrogen. 



1. Dr. ROBERT HARE, of Philadelphia, invented this instrument 

 in 1801 ; and in December of that year, the discovery was com- 

 municated to the chemical society of that city; in 1802, an account 

 of it was published in a pamphlet.* 1 It was used by Dr. Hare and 

 the author of this work, in 1802 3, and full accounts of their experi- 

 ments were published in the Phil. Trans, of Philadelphia, Vol. VI. 

 In Dec. 1811, an extensive series of experiments was performed by 

 the author, and published in 1812, in Dr. Bruce's Journal, several 

 years before Dr. Clarke's experiments were performed. j- 



2. Dr. Hare is entitled exclusively to the merit of the discovery. 

 The contrivance of mixing the gases before hand in explosive pro- 

 portions, is all that has been added, and this is not an improvement; 

 it introduces a serious danger where there was none before, and as 

 regards the heat produced, is attended with no important advantage. 



3. The principle of Dr. Hare's instrument is, that the oxygen and 

 hydrogen gases coming from distinct reservoirs, mingle at the mo- 

 ment of their exit from a capillary orifice, and are there ignited with 

 perfect safety. 



4. Dr. Hare first ascertained, that oxygen and hydrogen gases 

 can be made to burn together in this manner; that the heat thus 

 evolved, surpasses that produced by any other mode of combus- 

 tion, and that it is scarcely exceeded even by that produced by Vol- 

 taic electricity ; this might perhaps have been anticipated from the 

 great capacity of the gases, especially of hydrogen for heat.J 



* Which was republished in Vol. XIV, of Tilloch's Phil. Mag. Lond. and in Vol. 

 XLV, of the Ann. de China. Paris. 



t See Am. Jour. Vol. I, p. 98, and Vol. II, p. 181. 



t Being an independent original witness to the early use, (in 1802,) of this fine in- 

 strument by its inventor; and having been in the habit of using it frequently, for 

 several years before Dr. Clarke's experiments were published, as well as ever since ; 

 I embrace this opportunity to say, that no other name, than that of Dr. HARE, can be, 

 in my view, rightfully associated with the invention of the Compound Blowpipe. 



