Lesion I.] INTROIK * TORY NARRATIVE. 99 



if Agriculture appointed him Professor of Chemistry in Ib0'2, and engaged him 



to deliver a course of lectures On the Connexion of Clumutry tcith I'egetable Pftt/tiohgy, 



fhich wire highly appreciated, and he therefore continued to lecture at the meetings. 



i for ten successive years, on subjects connected with agriculture, which 



were published at the request of the Board in 1813. 



was elected a Fellow of the lloyal Society; in 1SOJ he was made a member 

 of the lloyal Irish Academy ; and, in 1806, he was elected Secretary to the lloyal 



, and chosen to deliver the Bakerian lecture before the Society, in which he 

 made known the results of his inquiries into galvanism and electricity. The following 

 year he discovered potassium, sodium, and boron ; and, in 1803, baryam, calcium, and 

 ttiontium. In 1810 he obtained the pri/e of the French Institute, and during that and 

 the following year he delivered two courses of lectures before the Dublin Society, for 

 which they voted him 11,30; and Trinity College, Dublin, conferred the degree of 



On the 8th of April, 1812, the Prince-Regent knighted him; and, on the llth, he 

 was married to Mrs. Apreece, a widow of fortune. The following year he was elected 

 Corresponding Member of the French Institute, and Vice-president of the Royal 



The most important of his discoveries was made in the year 1815. The many dreadful 

 accidents and great loss of life frequently occurring from the explosions in coal-mines, 

 occasioned by the fire-damp, induced some of the proprietors of mines to form a com- 

 at Bishop- Wearmouth, for investigating the causes of these frequent disasters, 

 and to consider the best means of preventing their occurrence in future. Sir Humphry 

 Davy's assistance was requested, and he immediately set out for the collieries, where he 

 obtained specimens of the fire-damp, for the purpose of analyzing on 



D to London ; and also made some experiments, with a view to 

 adopting a system of ventilation. After examining the fire-damp, and 

 trying numerous experiments, he discovered that the carburet ted hydrogen 

 gas, or fire-damp, would not explode when mixed with less than six, or 

 more than fourteen times its volume of air ; and that, when the gas did ex- 

 plode, the explosion could not past through apertures less than one-s 

 of an inch in diameter. Satisfied with these results, he construct. 

 tqfcty-kimi), which is generally termed by miners " It is a 



simple oil-lamp, enclosed in a long cylinder cage of wire gauze, which con- 

 tains about four hundred holes in the square inch. The wick 

 by a bent wire, passing tightly through a small tube in the body 

 lamp, so that the wick can be kept burning without unv 



!cr, an act that woul.l endanger the lives of the miners. The air 

 that passes through the wire gauze is sufficient to support combustion, 

 i produces enough carbonic acid and nitro fire- 



damp causing any explosion. When the air is foul, or charged with fire- 

 damp, the flame of the lamp becomes extinguished, and the int 



wire gauze cylinder is i . .should withdraw, 



other* ite by eon- >o long the gauze will be destroyed, and ai. 



explosion take place. When the lamp is removed to a purer air the wick becomes 



Tht Dart, or M iner Safety Lamp. 



