158 EULOGY ON GAY-LUSSAC. 



great warmth by Laplace and Berthollet. Sir Humphry Davy, who 

 was in no wise constrained by personal considerations, maintained that 

 the first interpretation alone was admissible ; he regarded oxygenated 

 muriatic acid as a simple body, that Amper^ proposed to call chlorine; 

 common muriatic acid became then the combination of this radical with 

 hydrogen, under the name of hydrochloric, or chlorohydric aoid. This 

 manner of interpreting facts is now generally adopted. 



It is seen by this example that there are cases where the counsels of 

 genius, when they assume the imperious character that counsels should 

 never have, may sometimes lead the soundest minds astray from truth. 



When the colossal battery constructed with the funds granted the 

 Polytechnic School by Napoleon was finished, Messrs. Gay-Lussac 

 and Th^nard were eager to study its efifects, but less energy was shown 

 than was expected. So after various trials, without striking results 

 the two illustrious chemists confined themselves to laying down gen- 

 eral principles on the mode of action of these apparatus when they 

 exceed the usual dimensions. We find in their work a chapter in which 

 they examined the different causes which create a variation in the energy 

 of the galvanic battery, in which they give the means of measuring its 

 effects, and in which they study the influence exerted by the liquid con- 

 tained in the troughs, according to its nature and the variations of in- 

 tensity which may depend upon the number and surface of the plates 

 employed. 



ANALYSIS OF ORGANIC MATTER, 



The analysis of aniuial and vegetable substances for some years has 

 received immense developments and led to the most important results. 

 This progress of the science is chiefly due to a method invented by Gay- 

 Lussac to effect organic analyses, and which has been adopted by all 

 chemists. Our colleague burned the substance to be analyzed with the 

 binoxide of copper. This process was a great improvement upon the 

 one he used with his associate and friend M. Th^nard, in which combus- 

 tion was effected by means of oxymuriate of potash, now known as 

 chlorate of potash. * 



RESEARCHES ON IODINE. 



M. Courtois, a manufacturer of saltpeter in Paris, discovered, about 

 the middle of 1811, in the ashes of varec a solid substance which cor- 

 roded his boilers, and which since, at the suggestion of Gay-Lussac, 

 has been called iodine^ from the extremely remarkable violet color of its 

 vapor. M. Courtois sent samples of this substance soon after its discov- 

 ery to Messrs. Desormes and Clement, who made it the subject of exper- 

 iment. M. Clement did not make public M. Courtois's discovery, and 

 the results he had obtained conjointly with M. Desormes, until the meet- 

 ing of the first class of the institute, December 6, 1813. Sir Humphry 

 Davy, who, on account of his scientific genius, had obtained from the 

 Emperor especial permission to pass through France, was then in Paris. 



