394 Scientific Intelligence. [May, 



the metallic appearance, invariably produced by the fusion of a 

 mixture of silica with animal oil, was wanting; silica mixed with 

 alcohol, spirits of turpentine, naphtha, Sec. was readily fused into 

 a transparent glass, analogous to that obtained in the last expe- 

 riment. Although the preceding experiments were instituted 

 for the purpose of ascertaining the nature of the metallic sub- 

 stance produced by the fusion of silica combined with oil, we 

 are obliged to confess that they appear to throw but little light 

 on the subject ; for if, as Dr. Thomson suggests, the metallic 

 appearance is occasioned by the charcoal contained in the 

 animal oil, why should it not also be obtained by the fusion of 

 other substances when mixed with oil ? on the other hand, from 

 the impossibility of producing a metallic appearance from the 

 silica when moistened with other fluids, the origin of this metallic 

 substance is still involved in obscurity. We should, therefore, 

 esteem it a particular favour if Dr. Clarke (through the medium 

 of your work) would favour us with his ideas on the subject ; and 

 we beg permission to ask that gentleman, whether the metallic 

 substance he denominates silicium was decomposed when sub- 

 mitted to the action of water, the nitric, muriatic, or nitro- 

 muriatic acids. I have the honour to remain, Gentlemen, 

 Your veiy humble servant, 



Joshua Mantell. 



XI. Employment of Sir H. Davy's Safety-Lamps in Flanders. 



An interesting pamphlet has lately appeared at Mons, on the 

 explosions that take place in coal-mines, and on the means of 

 preventing them, by the use of Sir H. Davy's safety-lamps ; it is 

 published under the direction of the chamber of commerce and 

 manufactures of Mons, accompanied by notes, and by the results 

 of a series of experiments, that were conducted by M. Gossart, 

 President of the Chamber. 



The province of Hainault is said to be more rich in coal-mines 

 than any other part of the continent of Europe, and to have no 

 less than 100,000 persons employed in the working them. The 

 same kind of dangerous accidents occurred in them as in the 

 north of England, and various expedients had been employed for 

 their prevention, which were, however, but little effectual in 

 obviating the evil. 



" All the precautions," the reporter observes, " which were 

 hitherto known or had been practised, had not been able to 

 preserve, in all cases, the unfortunate workmen from the terrible 

 effects of the explosion of the gas which is extricated in the 

 mines. It is then an inappreciable benefit which we confer, by 

 making known the method of preventing these accidents, equally 

 simple and infallible, which has been discovered by the celebrated 

 Humphry Davy." 



M. Gossart gives an ample and accurate detail of the nature 

 and properties of the carburetted hydrogen gas which is extri- 



