318 On the Chemical Evidence 



several insurances on their buildings and stock in trade, with 

 sundry insurance-offices, for various sums, amounting together 

 to 70,000/., and have paid to these offices nearly 1 ,000/. per 

 annum, to protect themselves from the peril of loss by fire. 



For several years the plaintiffs carried on their business by 

 the usual mode of boiling the sugar in large copper pans, fixed 

 in brick-work, and exposed to the action of naked fires. In 

 the month of August, however, in the year 1819, they erected 

 an apparatus for boiling sugar by means of heated oil, and one 

 of their pans was said to be thus worked, with great satisfaction 

 and profit, for nearly three months. In the month of November, 

 1819, a fire broke out upon the premises, by which the greater 

 part of the buildings was destroyed, and a loss sustained of 

 more than 80,000/. The cause of the fire has not yet been 

 ascertained. 



There has been no dispute with respect to the extent of the 

 loss — nor has any imputation been attempted to be cast upon 

 the conduct of the plaintiflPs ; but the defendants conceived, 

 that on certain grounds they were not entitled to make good this 

 loss, and especially on the ground of the plaintiffs having 

 adopted the new mode of boiling their sugar. 



The apparatus employed in this process was invented by Mr. 

 Daniel Wilson, civil-engineer. It consisted of a common sugar- 

 pan, a copper worm, a cast-iron forcing pump, and an oblong 

 wrought-iron vessel, similar in form to a steam-engine boiler, 

 fixed in brick-work, and heated by a common close fire-place. 

 Into this latter vessel about one hundred gallons of whale- 

 oil was put, and when the oil became heated to about 360° 

 of Fahrenheit, a part of it was driven by means of the pump 

 into a worm or coil of copper pipe, fixed within the pan 

 containing the sugar intended to be refined ; and when it had 

 passed entirely through the coil, it returned into the oil-vessel 

 by a different pipe of communication. Thus, so long as the 

 pump continued working, did the heated oil continue to circu- 

 late through the worm-pipe immersed in the sugar. The con- 

 sequence was, that the oil being heated to 340 or 360 degrees, 

 and the sugar boiling at a temperature of 240 degrees, the latter 



