4 Discordant Opinions of Chemists 



commence them with an examination of the second points, a» 

 stated in your last Magazine, which each partv wished to esta- 

 blish ; the gentlemen on the one side maintaining " that oil kept 

 at a heat of 360 degrees for two months, underwent no change 

 whatever, excepting becoming darker and thicker ; that by such 

 operation it did not become at all more inflammable." The 

 gentlemen on the other side asserting, '* that oil kept at the heat 

 and during the time above mentioned did become changed, that 

 partial decomposition took place, and that it became more in- 

 flammable." Here then tiiere is a decided contradiction of facts. 

 The above assertion on the plaintiffs' side was made by Dr. 

 Thomson, and was corroborated by mostofthe other witnesses, with 

 perhaps some slight modifications. They all allowed that an 

 aqueous vapour was given out, which condensed and fell back in 

 the boiler, and that the blackness of the oil was occasioned by 

 carbon being deposited. This aqueous vapour, as it is termed, 

 could not be the result of water mechanically combined with the 

 oil, because the whole of that, if there were any, would be expelled 

 before it arrived at the heat of 360 degrees. Now this vapour 

 continues to be produced the whole of the time it is submitted 

 to this heat. Aqueous vapour cannot be formed from oil without 

 that oil undergoing some decomposition. The hydrogen and 

 oxygen that leave the oil to form this vapour must disarrange 

 its elementary constituents, and the residue must be a compound 

 of a new order. Carbonic acid gas, it is stated, is given out, which 

 cannot be produced without some further change taking place- 

 Thus, Sir, on their own admission, we see that oil does undergo 

 a change more than merely in colour and density, and that a 

 decomposing process is going forward all the time it is submitted 

 to that heat. It is somewhat surprising, that men to whose 

 opinions so much importance is attached, and who are looked 

 up to with so much deference, should not have made themselves 

 acquainted with every circumstance that was necessary to enable 

 them to give a correct opinion upon every point on which they 

 might be examined, particularly when so much time was allowed 

 them between the two trials to gain all the information possible. 

 That which was termed aqueous vapour, is in fact not simply 

 aqueous vapour, but combined with an inflammable vapour and a 

 large portion of acetic acid, which is formed in the oil : their 

 calling it aqueous vapour at least demonstrates that they assumed 

 itwasso without provingit; and if they admitassumption in onein- 

 stance, their opponents mayjustlv charge them with it in others; for 

 they ascertained the vapour to be acid, and that it was aceticacid*. 



All 



• It may be said, this is not a new fact; as it was well known, and had 

 been .-loticed in chemical works, that acetic acid comes over with the vapour 



that 



