712 PROCEEDINGS OF THE MIERICAN ACADEMY, 



o„i,<,+„„„„ C.c. Air T^o Bar. Vapor 



Substance. replaced. ^ • Corr. Density. 



1. 0.0522 g. 17.93 19.5 751.1 mm. 2.4 



2. 0.0516 g. 18.15 19.5 751.1 mm. 2.4 



Calculated for SO3HCI 4.04 



Analysis. — A gravimetric analysis resulted as follows: 



1 0.9145 g. substance gave 1.1272 g. AgCl 

 1.2557 g. substance gave 1.5480 g. AgCl 

 0.5364 g. substance gave 1.0824 g. BaS04 

 0.7266 g. substance gave 1.4655 g. BaS04 



1. 

 2. 

 3. 



4. 



Properties of Mixtures of Pyrosulphuryl Chloride and Chhr- 



sulphonic Acid. 



The presence of the two bodies in the product of the Schiitzenberger 

 reaction and their close relation to each other rendered of interest a 

 comparison of certain properties of their mixtures. As differentiating 

 properties were selected the melting point, boiling point, action with 

 water and with finely powdered tellurium and selenium. The samples 

 of pyrosulphuryl chloride and chlorsulphonic acid used were free fr'om 

 any admixture of the other. The amounts of mixture made up averaged 

 30 grams. The chlorsulphonic acid gave with tellurium an instantane- 

 ous cherry red, persisting for several hours but finally fading. With 

 selenium it gave an immediate moss-green, gradually becoming fainter, 

 then yellow in about an hour, fading in three hours. No colors were 

 obtained with pyrosulphuryl chloride. The table on p. 713 (Table 

 III) gives the results concisely. 



From inspection of this table it will he seen that a little over 

 five per cent of chlorsulphonic acid in a mixture of the two bodies 

 would give a color reaction and depress the melting point. Ten per 

 cent would not only give a color reaction, but would cause a consider- 

 able lowering of the boiling point and a more immediate action with 

 water. Thirty per cent would give a strong color reaction, a marked 

 action with water, and a marked lowering of the melting point. A 

 chlorsulphonic acid containing thirty-five per cent of pyrosulphuryl 

 chloride would hardly be distinguished from pure material by the color 

 reactions and the action with water, nor would the boiling point suggest 

 much impurity, but the presence of pyrosulphuryl chloride in such a 

 mixture might be inferred from the melting point. It is noteworthy, 



