288 Hare’s Blowpipe. 
vault employed im England to regulate the blast of large 
bellows at founderies and forges. Mr. Brook was the first 
to apply it ts the regulation of a blowpipe, and published 
his account of it in April 8th, 1816. 
I will proceed to quote and exhibit simultaneously, the 
observations and experiments of Dr. Clark, and of Profes- 
sor Silliman and myself. As Tilloch’s Philosophical Mag- 
azine is universally accessible, I shall refer to it for the me- 
moirs of Silliman and myself: to vol. 14 for mine, to vol. 
50 for his.* For Dr. Clark’s experiments, commenced in 
1816, I shall quote his book on the gas blowpipe, publish- 
ed 1819. 
Experiments on Lime. 
Hare, page 304. ‘* Lime and magnesia are extremely 
difficult to fuse, not only because they are the most refrac- 
tory substances in nature, but from the difficulty of prevent- 
ing them from being blown on one side by the flame : -nev- 
ertheless, in some instances, by exposure on carbon to the 
gaseous flame, small portions of these earths were convert- 
ed into black vitreous masses. Possibly the black colour 
of these products of fusion, may have been caused by iron 
contained in the coal; for in the high temperature of the 
gaseous flame, a powerful attraction is exerted between iron 
and the earths.” 
Hare, page 306. ‘There is a peculiar species of native 
coal found on the banks of the Lehigh in this State, which 
is extremely difficult to ignite ; which, when exposed to a 
high degree of heat and a copious blast of air, burns, yield- 
ing an intense heat without either smoke or flame, and 
leaving little residue. By exposure to the gaseous flame 
on this coal, both magnesia and lime exhibited strong symp- 
toms of fusion. The former assumed a glazed and some- 
what globular appearance, the latter became converted into 
a brownish semivitreous mass.” 
Silliman, page 109. “ A piece of lime from the Carrara 
marble, was strongly ignited in a covered platinum cruci- 
ble ; one angle of it was then shaped into a small cylinder, 
_ * These experiments were performed in December, 1811, and published 
in Bruce’s Journal in 1812. 
