1826.]" Royal Society, 22'? 



Vvhich accounted for the different statements made by various 

 writers respecting the mutual action of the two substances. 



Cold pulverized naphthaline having been put into three or four 

 parts of cold concentrated sulphuric acid, and agitated and left for 

 several days, was gradually dissolved, forming a red mixture of a 

 crystalline and a fluid matter, vvhich, upon the addition of water, 

 dissolved almost entirely, yielding a solution of a peculiar, bitter, 

 acid taste. 



Upon fusing about two parts of naphthaline with one part of 

 strong sulphuric acid in a flask, and agitating them together, 

 a perfect mixture was obtained, but which on standing sepa- 

 rated, whilst fluid, into two portions, both deep-red, but the 

 heavier much more so than the lighter. Being poured into 

 tubes, retained hot for some time to admit of separation, and 

 then allowed to cool, both substances crystallized, and became 

 opaque and deep-red. Being separated they were examined ; 

 the upper was crystalline, and hard like naphthaline ; it was 

 sapid ; and being heated with a little water, was separated into 

 nearly pure naphthaline which floated, and an acid which dis- 

 solved in the water : the lower substance was much heavier than 

 the former, softer, crystalline, deep-red in colour ; exposed to the 

 air it became moist on the surface from the commencement of de- 

 liquescence, and then harsh from the separation of naphthaline. 

 It was highly bitter, and burnt in the air with much flame. 

 When rubbed with water, about a fourth part of its weight of 

 naphthaline separated, the rest being soluble, and similar to that 

 extracted from the lighter substance. 



Upon neutra,lizing some of this acid with potash, and digesting 

 the salt formed with alcohol, it was found that the alcohol upon 

 evaporation left a white, dry, and crystalline salt, which, when 

 heated in the air, burnt with much flame, and which, being solu- 

 ble in alcohol, and not precipitating salts of barytes and lead, 

 was strongly distinguished from a sulphate. 



In this way it appeared that sulphuric acid and naphthaline 

 might be combined producing a new acid, which, as it existed 

 in large quantities in the heavier substance, mixed with free sul- 

 phuric acid, was now to be separated from it, and obtained in a 

 pure state. For this purpose a specimen of native carbonate of 

 barytes was selected, and rubbed to powder with the solution 

 of the impure acid until it had been rendered neutral; the water 

 was found to contain a soluble barytic salt, and upon washing 

 the solid residue at the bottom of the mortar with more water, an ad- 

 ditional portion of the same salt was obtained, the sulphate of ba- 

 rytes and excess of carbonate remaining untouched. The barytic 

 saltinsolutionwasnow decomposed by the addition of such quan- 

 tity of sulphuric acid as would precipitate all the barytes and leave 

 no excess, so that by filtration a solution of the new acid was 

 obtained. It was colourless and transparent, did not precipitate 



«2 



