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LXII. "Remarks on a Paper by Mr. Dalton on the Chemical 

 Compojinds of Azote and Oxygen, &c. By William Hig- 

 GiNs, Esq. 



To Mr. Tilloch. 



Sir, — X ou will oblige me by inserting in your candid and 

 useful Magazine the following remarks on a paper of Mr. Dal- 

 ton on the Chemical Compounds of Azote and Oxygen, &c. which 

 appeared in the number of Dr. Thomson's Annals of Philosophy 

 for February. 



It is stated that this paper was read before the Literary and 

 Philosophical Society of Manchester in the year 1816. That 

 it should lie by since is not to be wondered at, as containing no- 

 thing new ; it relates to a hackneyed subject, which chemists 

 have lately gone over repeatedly. 



In that part of my ])aper which appeared in your excellent 

 Magazine for December 1816, I observed that Dr. Thomson 

 stepped forward repeatedly in a very unjust cause, which could 

 never do him credit, as the advocate of Mr. Dalton, while the 

 latter stood silent and trembling at the bar of justice. 



In consequence of the aI)ove observation it was, I suppose, 

 that his friend urged him on with his tale, which is obscurely and 

 contradictorily told ; and I may add evasively and unjustly so, re- 

 specting myself. But the sole object was to say something on 

 any part of my system with a view to show his face and a confi- 

 dence of his innocence, at the same time that no mention should 

 be made of the person whom he so glaringly attempted to injure. 



I will now give a very cursory view of this paper, for more is 

 not necessary. " Lavoisier (he says) \vas the first who ascer- 

 tained the constituents of the atmosphere, thirty years ago." 



Priestley was before Lavoisier in the discovery : but it is of no 

 consequence, as to my present object, which of them was first or 

 second, except in point of justice, which we should never lose 

 sight of as men or philosophers. But Mr. Dalton goes on, 

 ** Lavoisier in consequence of vague and contradictory expressions 

 was not decided whether the oxygen and azote of the atmosphere 

 were mixed only, or chemically united ; and as in his table of 

 binary combinations of azote with simple substances no men- 

 tion is made of atmospheric air being one of them, it is likely he 

 considered it as a simple mixture." 



This is puerile : there is no chemical combination of azote and 

 oxygen in the proportion in which they exist in our atmosphere ; 

 and were they chemically united, it would be unfit to support 

 animal life. 



Chaptal comes next. " lie was decisively of opinion that 

 Vol. 49. No. 228. y/pn7lS17. Q <^^n- 



