1865.] Dr. Stenhouse On Sulphobenzolates. 89 



and Brochantite with Atacamite, the streak of which is of a characteristic 

 apple-green. 



M. Pisani has published analyses of the two above-described minerals. 

 In the former (possibly from having driven off part of the water in the 

 preliminary desiccation of the mineral) he has found less water than I 

 consider it really to contain, and he has consequently given to Langite 

 the formula of Waringtonite. 



The green mineral which he has analyzed and described as Brochan- 

 tite seems, from his analysis, to have contained a slight admixture of the 

 ferruginous matrix, and also differs from mine in the estimate of the water. 



I confined my preliminary desiccation to a careful treatment of the 

 bruised mineral with dried and warm blotting-paper, as many hydrated 

 minerals of this class yield up part of their water when long exposed to a 

 perfectly dry air, or to a temperature of 100 C. 



II. "Preliminary Notice on the Products of the Destructive Distilla- 

 tion of the Sulphobenzolates." By JOHN STENHOUSE, LL.D., 

 F.R.S., &c. Received February 15, 1865. 



The salt which I have hitherto chiefly employed is the sulphobenzolate 

 of soda, C, 2 H 5 Na 2SO 3 , which was prepared according to Mitscherlich's* 

 directions, by precipitating crude sulphobenzolate of lime by carbonate of 

 soda, separating the carbonate of lime produced, and evaporating the clear 

 solution to dryness. The finely powdered salt, which had previously been 

 thoroughly dried, was introduced into a small copper retort and subjected 

 to destructive distillation, when a considerable quantity of carbonic acid 

 was evolved, and a brownish-coloured oily liquid, covered by a layer of 

 water, collected in the receiver. 



This oil was separated from the water and distilled in a retort furnished 

 with a thermometer. The liquid began to boil at 80 C., and then rose 

 slowly to 110 C., when only a small quantity of water, and an oil consisting 

 chiefly of benzol, came over. The boiling-point then rapidly rose to 290 C., 

 at which temperature the greater portion of the liquid distilled over, leaving 

 a black residue in the retort. 



The oil boiling at 290 C. is of a pale yellow colour, heavier than water, 

 and has an aromatic and slightly alliaceous odour. It contains a consi- 

 derable amount of sulphur. 



"When this oil is brought in contact with nitric acid, a very violent action 

 ensues with evolution of nitrous fumes, and when the resulting solution is 

 poured into water, a crystalline mass of a pale yellow colour is obtained. 

 This, when dried and washed with ether to separate a small quantity of 

 adhering oil, is dissolved in hot spirit, from which, on cooling, two colour- 

 less crystalline substances separate. 



The first of these, which constitutes the bulk of the product, forms 

 beautiful rhombic plates, which, when crystallized out of benzol, may be 

 * Fogg. Ann. vol. xxxi. pp. 283 & 634. 



