708 PROCEEDINGS OF THE AMERICAN ACADEMY. 



not pyrosulphuryl chloride.^i as shown by the boilmg and melting 

 points and by the low specific gravity. 



Preparation 10, which was viscous at —124°, was regenerated irom its 

 sodium salt and studied with more care as to exclusion of moisture. 

 It boiled at 73-75° (21 mm.), became viscous at —128-126°, and had a 

 specific gravity of 1.767 at 20°. 60 grams of this were then distilled at 

 atmospheric pressure until about one third came over. Of the remain- 

 der, about 10 grams were distilled at low pressure (t°, 63°, p., 24 mm.), 

 a U-tube with liquid air being used. In the U-tube was found a 

 small amount of solid, with properties resembling those of sulphuryl 

 chloride. The residue was then placed in the apparatus described on 

 page 698 (Figure 2). After passing dry air through the system for 

 an hour, the liquid was distilled into the second flask at 76-78°( 23 mm.), 

 when the second flask was sealed off and the distillation conducted at 

 ordinary pressure. It began at 139°, and was chiefly from 149° to 150°. 

 The formation of gas was evident and chlorine was found in the liquid 

 air tube. Sulphuric acid was left in the residue. The distillate be- 

 came viscous at —128° ; a few crystals were visible at —80°, disappear- 

 ing at —67°. 



The study of the crude product of Preparation 13 was to throw more 

 light on the question. This had boiled, in hydrochloric acid, within 

 closer limits, 150-154°, than previous preparations. The latter, owing 

 to presence of much hydrochloric acid or of products of dissociation, 

 had taken the vitreous form on cooling, becoming viscous at a higher 

 temperature without separation of crystals. In this case, however, the 

 viscous liquid became solid with crystals at —110°, which disappeared 

 at —70°. 



330 grams of this preparation were distilled at 19 mm., after drawing 

 off most of the excess of hydrochloric acid by exhaustion. 58 grams 

 were collected from 67° to 76°, 177 grams from 75° to 78° and 55 grams 

 were left, largely sulphuric acid, which had probably distilled in the 

 hydrochloric acid current. In the U-tube was much hydrochloric acid ; 

 a little chlorine. The first fraction became viscous at —127°, crystal- 

 lized at —93°, and melted at —54°. The corresponding figures for the 

 second were —134-129°, —87°, and —74°. In both fractions cooling 

 caused no separation of crystals. The second fraction, on redistillation 

 at low pressure, became viscous at —130°, crystallized at —83°, and 

 melted at —72°. There was again no separation on cooling. In the 



®^ We prepared a small quantity of sulphuryl chloride by the method of 

 Ruff. This boiled at 69-71" and melted at —58-56°, corr. With water it formed 

 an oil, dissolving quietly. The specific gravity of sulphuryl chloride is given 

 as 1.661 at 21°; the boiling point 75°. 



