116 ON THE VALUE OF CHEMISTRY, &C. 



ments which exposed you to such danger ? " Now this 

 same individual had twice in the regular exercise of his 

 business narrowly escaped being killed. The fact is 

 that use what precautions we will we are still obnoxious 

 to dangers of different kinds which we cannot foresee ; 

 the most expert rider may be thrown occasionally, and 

 the ablest seaman cannot avert the storm which over- 

 whelms his vessel. In general however accidents 

 which occur in Chemistry arise from abstraction from 

 the business in hand owing to the mind's being diverted 

 by conversation or other matters ; there are but few 

 experiments in Chemistry of a dangerous nature and 

 these even are not so if conducted with moderate 

 caution . The writer of this had been for a considerable 

 time engaged in a highly interesting scientific investi- 

 gation of the pheomena of flame with the intention of 

 examining its peculiar modifications, both in vacuo 

 and the open air, so as to discover, if possible the 

 peculiar laws and conditions on which its existence 

 and action depend. He had succeeded in obtaining 

 several new and interesting results; he found, for in- 

 stance, that inflammable mixtures which even con- 

 tained the elements of combustion within themselves 

 could not be made to ignite in vacuo, and that sulphuric 

 acid would not cause the combustion of Chlorate of 

 Potas and Sulphur when the air within u receiver was 

 considerably rarefied * having occasion for a portion of 

 fulminating silver in the course of the investigation he 

 prepared a quantity in the usual w r ay, this is done by 

 dissolving silver in 'Nitric Acid and adding to it Spirits 

 of Wine just before the solution of the silver is finished, 

 this produces a very violent action, nitrous gas and 

 nitrous ether are evolved in abundance, as soon as this 

 subsides a little, w r ater is added to suspend it entirely ; 

 a white curdy precipitate is thus formed which speedily 

 settles at the bottom, this is fulminating silver ; the 

 solution w r hich consists of a portion of uridecomposed 



* An Account of these experiments will be given in a future 

 number. 



