160 EULOGY ON GAY-LUSSAC. 



radical from prussic acid, which has since been denominated cyanogen. 

 He established the fact that cyanogen is a compound of azote and car- 

 bon; that prussic acid is definitively formed from hydrogen and this rad- 

 ical: and that it should take the name of hydrocyanic acid, for which 

 chemists now often substitute that of cyanhydric acid. He points out 

 with the greatest care its reactions on a great number of substances, 

 simple or compound, solid or gaseous. He makes known the combina- 

 tion of cyanogen with chlorine, which should naturally bear the name 

 of chloro-cyanic acid. In brief, in this work Gay-Lussac filled a gap in 

 chemistry by showing that there exists a combination of azote and 

 carbon. He proved that cyanogen, although a comix)und, plays the 

 part of a simple body in its combinations with hydrogen and metals, 

 which, at the period when our colleague wrote, was the sole example in 

 the science. I have said that, to establish results so grand, Gay-Lus- 

 sac displayed indefatigable perseverance. If proof of it is wanted, I 

 will mention, for instance, that, wishing to know what modifications 

 electricity could produce in a mixture of two gases, he passed into it 

 at least fifty thousand sparks. 



We read with great regret, in the memoir of our colleague, the follow- 

 ing paragraph : " I had indulged the hope, in devoting myself to these 

 researches, of being able to throw some light on all the combinations of 

 hydrocyanic acid ; but the duties I have to perform have forced me 

 to interrupt them before they had reached the degree of perfection to 

 which I expected to bring them." What were these duties which, in 

 1815, hindered Gay-Lussac from completing this work of genius ? It 

 was — and I mention it with regret — the necessity of providing for his 

 family, by giving public lectures almost daily, which consumed the 

 time our friend had wished to devote more usefully to the advance- 

 ment of science. 



Cyanogen, one of the constituent principles of Prussian blue, furnishes, 

 by combining with hydrogen, a poison so subtile that a celebrated phys- 

 iologist, the first to use it in experiments on living animals, exclaimed, 

 on seeing its eft'ects, " Henceforth one may believe all that antiquity 

 has said of Locusta." The same learned academician has proved by 

 his experiments that in the poisoned animals no lesion in the organs 

 essential to life is seen. 



This action of the liquid obtained for the first time by Gay-Lussac 

 will appear the more mysterious from the fact that it is produced by a 

 substance comi>osed of azote, one of the constituent principles of atmos- 

 pheric air, of hydrogen, one of the constituent principles of water, and 

 carbon, whose innocuousness is proverbial. One more reflection, and I 

 have done with this article. Chemists never fail, when they discover a 

 new jjroduct, to describe its taste. Who does not think with horror that 

 if he had not departed from the usual custom, if he had placed one 

 single drop of this liquid on his tongue, our friend would have fallen 



