112 Mr. Parkes' additional Obaervations 



This passage reminds me of a very important experiment, at 

 which I assisted in the month of December last ; and which I 

 think, notwithstanding the above assertion, the Associates them- 

 selves will allow to exceed, both in magnitude and importance, 

 any of their experiments ; besides its possessing an advantage 

 which none of theirs can boast, viz., that it was made in an appa- 

 ratus exactly similar, both in form and size, to the one which 

 existed at the sugar-house at the time when the fire happened. 

 The particulars are as follow : — 



On the second trial, the chemists, who were examined on be- 

 half of the defendants, advanced a new theory, viz., that if heat 

 be applied to whale oil with great rapidity, and to a high de- 

 gree, results very different from what might be expected in the 

 common mode of heating will be obtained. In consequence of 

 this, it was suggested that it would be advisable to ascertain 

 what would be the eftect of the rapid heating which they de- 

 scribed, if tried upon the oil in the large vessel at VVhitechapel, 

 and which had been kept heated to 340° and 380° for forty-one 

 days, and for ten hours in each day. 



Accordingly, on Saturday evening, the 16th of December, 

 while the trial was pending, Mr. Dalton, Mr. Cooper, Mr. Wil- 

 .son, and I, went down to the sugar-house, for the express 

 purpose of putting this new theory to the test of actual experi- 

 ment. And in order completely to meet their assertions, we did 

 not light the fire under the oil in the usual manner, but deter- 

 mined to prepare the fire previously, that it might be applied to 

 the oil as suddenly as possible ; and we proceeded thus : 



At nine o'clock at night, a fire was lighted upon a black- 

 smith's hearth, which, fortunately, was situated close to the 

 room in which the oil-vessel stood. This fire was urged by the 

 smith's bellows until the fuel was completely lighted up, and 

 then it was put at once from thence into the fire-place, over 

 which the oil-vessel stood ; and at that time the vessel contained 

 more than 100 gallons of that oil, which had for so long a time 

 been submitted to the repeated heating already mentioned. 



While the fire was preparing, two long thermometers, highly 

 graduated, were fixed in the vessel, one of which was merely 



