Miscellanies. 371 



December 20, 1839. — Doctor Hare made a verbal communication 

 relative to the application of radiant heat to glass. 



The combustion of anthracite coal, in an open grate, in his labora- 

 tory, having four flues of about 4.12 by 2. 12 inches each, in area, just 

 above the level of the grate, (the upper stratum of the fire having 

 nothing between it and the ceiHng,) had allowed him to perform some 

 operations with success, which formerly he would have considered 

 impracticable. The fire having attained to that state of incandes- 

 cence to which it easily arrives when well managed, he had, on open- 

 ing a hole by means of an iron rod, so as to have a perpendicular 

 perforation extending to the bottom of the fire, repeatedly fused the 

 beaks of retorts of any capacity, not being more than three gallons, 

 causing them to draw out, by the force of gravity, into a tapering 

 tube; so that, on lifting the beak from the fire, and holding the body 

 of the retort upright, the fused portion would hang down so as to 

 form an angle with the rest of the beak, or to have any desired 

 obliquity. By these means, in a series of retorts, the beak of the 

 first might be made to descend through the tubulure of a second ; the 

 beak of the second through that of a third, and so on ; the beak of 

 the last retort in the row being made, when requisite, to enter a tube 

 passing through ice and water in an inverted bell-glass. 



Dr, Hare further communicated a method of preparing pure chlo- 

 rohydric acid, from the impure muriatic acid of commerce, by the 

 action of sulphuric acid. 



It is known, said Dr. Hare, that concentrated sulphuric acid, when 

 added to liquid chlorohydric acid, expels more or less of it as a gas, 

 in consequence of its superior afiinity for water. At the present low 

 price of the ordinary acid of commerce. Dr. Hare had found it advan- 

 tageous to procure the latter in purity, by subjecting it to the former. 



A tubulated glass retort, having been half filled with chlorohydric 

 acid, sulphuric acid was allowed to drop from a glass funnel, with a 

 cock, into a tube descending into the acid in the retort, through the 

 tubulure, to which it was luted by strips of gum-elastic. The tube 

 terminated in a very small bore. The beak of the retort, bent in the 

 fire, as he had just described, descended through the tubulure into the 

 body of a small retort containing water not refrigerated. The beak 

 of the latter descended into a larger one, half full of water, to which 

 ice was applied. Of course the beak of the third might, in like man- 

 ner, enter the body of a fourth. After an equivalent weight of sni- 

 per time, we do not insert it, ahhough it is a most able document, and should be 

 generally read. This letter, owing to the representations of the Secretary of War, 

 was referred to a select committee of Congress. — Eds. 



