265 



netism was produced. The same result was afterwards obtained in 

 comparative trials ; the steel was found to be no way affected by 

 white light. 



As the season advanced and the sun's force diminished, these ef- 

 fects became more feeble, and further experiments were in conse- 

 quence deferred till the return of summer ; but from the experiments 

 here detailed, the authoress thinks herself entitled to regard a mag- 

 netic influence in the more refrangible solar rays as demonstrated. 



On the mutual Action of Sulphuric Acid and Naphthaline, and on a 

 new Acid produced. ByM. Faraday, F.R.S. Corresponding Mem- 

 ber of the Royal Academy of Sciences, &c. 8fC. Communicated Ja- 

 nuary 12, 1826. Read February 16, 1826. [Phil. Trans. 1826, 

 Part II. p. 140.] 



In this communication Mr. Faraday shows that when sulphuric 

 acid and naphthaline act upon each other, a peculiar compound pos- 

 sessed of distinct acid characters is the result. This acid is most 

 readily obtained by heating two parts of naphthaline with one of 

 sulphuric acid. The mixture concretes on cooling, and separates 

 into two parts, the uppermost of which is little else than naphthaline, 

 but the lower, heavier part contains the peculiar acid, which, being 

 soluble in water, is easily separated by that fluid, not, however, pure, 

 but still containing mixed sulphuric acid. The author, however, ob- 

 tained the pure acid by decomposing its compound with baryta, 

 which is soluble, by sulphuric acid. It then had a bitter sour taste, 

 and formed a distinct class of salts with the different bases, all of 

 which are soluble in water and in alcohol, and combustible. 



By careful evaporation of the aqueous solution of this acid, a white 

 crystalline deliquescent solution was obtained, evolving water when 

 heated, and at high temperatures affording sulphurous acid, char- 

 coal, and naphthaline. To determine the ultimate component parts of 

 this acid, its compound with baryta was subjected to rigid analysis; 

 the results of which were 



78 baryta = 1 proportional. 



80 sulphuric acid = 2 proportionals. 



120 carbon =20 



8 hydrogen = 8 



This acid, therefore, only possesses half the saturating power of 

 sulphuric acid, and it would accordingly appear that the hydro- 

 carbon acts the part of a ueutralizer of one of the proportionals of 

 sulphuric acid. This property of hydro-carbon, the author observes, 

 was pointed out to him by Mr. Hennell, as manifested in the for- 

 mation of sulpho-vinous acid, before he had established it in regard 

 to the above peculiar combination. 



Mr. Faraday proposes to call the acid, of which he has described 

 the sources, nature, and properties, Sulpho-naphthalic Acid. 



