Institnte of France. 229 



|n a prcat measure for the restoration of the liberty of writing 

 and thinking, had scarcely hiid down their arms, when they 

 flocked to make themselves acquainted v.ith our labours, to take 

 a share in them, and to instruct us as to what was done among 

 themselves." 



The reporter commences with chemistry, and notices the dis- 

 coverv of iode, recapitulating its properties. 



" When Lavoisier and Berthollet formed the new system of 

 chemistry on their beautiful experiments, which demonstrated 

 their luminous theories of combustion, the formation and de- 

 composition of water, and of the formation of the acids by tlie 

 cpmbinatiou ofoxyi^en with different bases ; when this truth w;is 

 complctaly established Ijy evidence, so far as the principal acids 

 were concerned, it was inferred from analogy that it might be 

 extended to all. Nevertheless, some scruples arose on this sub- 

 ject, as soon as it was ])roved by M. Berthollet that sulphuretted 

 hydrogen had the properties of the acid'^, although oxygeii U'a'i 

 no part of its composition. It was acknowle:igcd that oxygf^n 

 was not the only principle capable of operating acidification. 



" The muriatic acid, that acid which combined with soda 

 forms common salt, had not been decomposed : and tlie oxy- 

 gerjated muriatic acid, a substance so precious from the property 

 which it possesses of disinfecting the air by neutralizing putrid 

 miasmata, and from its use in bleaching, — this substance, which 

 iiad been long regarded as a combination of the muriatic acid 

 with a superabundance of oxygen, may be regarded as a simple 

 substance, from a variety of concurrent circumstances, as a burn- 

 ing (coml'/tran) or acidifying principle as well as oxygen : and 

 most chomists who have adopted this opinion, those who are 

 considered as the best authorities, have called it c hlnre, homthii 

 yellowish colour which they found it to possess. The muriatic 

 acid, according to them, is a combination of cfilure with hydro- 

 gen, and they call it hydrochloric acid, 



" lode also forms acids by being combined wjth hydrogen 

 and other substances : we must therefore place it with chlore and 

 sulphur among the number of acidifying principles, 



"A fourth iniiiciple is sought to be discovered in the fluoric 

 acid, and hitherto ngt decomposed. This acid is remarkable 

 for its property of corroding glass, so that it can only be kept in 

 flasks internally coated with wax. This property has been taken 

 advantage of for niaking drawings upon glass by means of the 

 fiuoric acid reduced into v;ipour. We jjresume that it results 

 from the composition of hydrogeti, with a simple body of a pe- 

 culiar nature, and which we shall call Jli/or, It was M. Ampere, 

 a most eminent geometrician, who first conceived this idea, and 

 it is for professional chemists to demonstvale it, 



I' q ^' Will 



