92 Mr. Parkes' addilioiial Observations 



I know, as well as they, that oil, if allowed to expahd freely 

 iji an open vessel, would exhibit none of the fearful phenomena 

 which they have described ; but when confined in a vessel with 

 no orifice except that of a small tube, and in such a quantity, 

 as when expanded by heat would be more than sufHcient to fill 

 the vessel, then the liquor not getting vent so fast as the fire 

 produces the expansion, it would act like a syringe, and the oil 

 would be forcibly expelled from the mouth of the tube. If the 

 heat of the fire were intermitting, this expulsion would be inter- 

 mitting also, and we should then have all the spoutings and the 

 dashings against the ceiling, from the circumstance of the ex- 

 pansion alone. Did these gentlemen never see the water dart 

 suddenly out of the spout of a tea-kettle from expansion, and 

 tliis before the water had acquired a boiling heat? 



But even were there two or three inches of vacancy in the 

 vessel (and there could not have been more, even by their own 

 shewing*, for they say they put in twenty-four gallons, which 

 we know would be expanded by heat to twenty-nine gallons), 

 this vacuity would be filled with vapour, in consequence of the 

 large quantity of water which is always formed in oil at a high 

 temperature ; and this being generated faster than it could be 

 carried off by the tube, would press with a force on the surface 

 of the oil, that would be sufficient to produce all the effects 

 which tliey have related. 



Respecting my notice of the term " silent explosion," they 

 have made the following observations : " In the Rudiments of 

 Chemistry, p. 115, Mr. Parkes tells us, that prussic acid has 

 a sweet taste ; and there is even reason to suppose, that he is 

 actually a believer in explosions without noise, for in page 570 

 of the Chemical Catechism, he j,^fines detonation to be an ex- 

 plosion with noise, which manifestly implies that, in his opi- 

 nion, noise is not necessary to explosion. Now, in all fair- 

 ness, I think Mr. Parkes must allow, that he who describes 



* They have made two calculations as to the quantity of oil which their 

 vessel would hold, viz., one at page 44, aud the other at page 51 of their 

 book. Aud thougli they are calcu alums which any school-boy couhl have 

 made, they arc both erroneous. 



