ON FLUOR 39 



mistake, to commit another in the very same experiment 

 by which he thinks to attain his purpose. 



Truth, however, let the dispute be carried on in what- 

 ever manner, is commonly a gainer ; and this is no small 

 advantage. 



SECTION II. 



This has been the fate of the fluor acid, a substance 

 made publicly known by that excellent chemist Mr. Scheele, 

 in the Swedish Transactions. 



Many doubted concerning it, but its most zealous 

 avowed opposers were, as far as I know, Mr. Boullanger 

 and Mr. Monnet. Though I had made but few experiments 

 with it when I read Mr. Monnet's essay, yet I easily per- 

 ceived that, while he charged Mr. Scheele with having 

 observed wrongly, his own observation had been still more 

 faulty. 



I resolved to defend my friend ; but, learning that he 

 was himself making experiments in order to refute his 

 adversaries, I willingly relinquished the task to his masterly 

 hand. I read with satisfaction the experiments published 

 by him, with this view, in the first quarter of the Swedish 

 Transactions for 1780 ; and, moreover, translated them, in 

 order to communicate them to my countrymen in some 

 journal. 



Hence I was led to repeat a few experiments, and 

 these again suggested others ; and, as I think them likely 

 to contribute somewhat to a more intimate knowledge of 

 this remarkable stone, I lay them before the Society. 



