372 Dreadful Accident occasioned ly the Explosion 



I was very well aware of the probability of my placing some 

 of my analyses in a very unfavourable light, bv contrasting the 

 results obtained by the application of a theory capable of giving 

 the composition of bodies with absolute certainty, with those 

 results which I have obtained by practical experiments on a 

 class of bodies hitherto little examined or imderstood, and the 

 analyses of which were very difficult: but I would not allow this 

 consideration to have any influence in deterring me from making 

 such a contrast; for, as I had not tlie vanity to give these analyses 

 as perfect, so I feel no mortification in now proving that they 

 were not so ; and being confident that I had not spared either 

 time or trouble in making them, 1 expose their imperfections 

 without hesitation, confiding in the candid judgement of those 

 who, having undertaken similar investigations, are aware of the 

 numerous difficulties and sources of error attendant upon them. 



I have arranged and collected these comparisons into the 

 form of a Table, which I beg leave now to introduce. 



I infer from the Table, that the acids and salts included in it, 

 are so composed as to harmonize perfectly with the doctrines of 

 Dalton and Berzelius^ and to be very compatible with the epi- 

 nion respecting the compound nature of azote. 



I shall be happy if this attempt to elucidate the nature and 

 composition of these bodies adds in any degree to the daily and 

 rapid progress now making in chemical science. 



Tower, Feb, 22, 1815. RoBERT PoRRETT, Jun. 



LXIX. Dreadful Accident occasioned ly the 'Explosion of a 

 Boiler at Mr. Constant's Sugar-House in Well-Street on 

 the loth of November. 



-It has lately been ascertained that when the boiling of sugar, 

 in the process of refining, is carried on without any fire being 

 allowed to come directly in contact with the pan, a waste of 

 sugar is prevented, and a better article obtained. On the pro- 

 cess of refining we do not mean to offer any remarks, but merely 

 to speak of the accident which has occurred in consequence 

 of steam being employed, in an injudicious manner, to boil the 

 sugar pans in place of fire as hitherto. The arrangement was 

 simply this: — A large close boiler was constructed for the pur- 

 pose of generating steam, to be conveyed through tubes, under 

 the sugar pans, to brMig them to the required temperature for 

 boiling the syrup. These pans, made of copper, were each put 

 into an exterior pan made of cast iron, and closely joined at their 

 brim to prevent the escape of steam. Only one pan we believe 



had 



