I. Remsen on Parasulphobenzoice Acid. 277 
2 
Parasulphobenzoic Acid, C%H! a : 4 - is prepared from 
the barium salt by precipitating the barium exactly with pure 
sulphuric acid, and evaporating the solution. It is very easily 
soluble in water, and crystallizes from a very concentrated solu- 
tion in the form of beautiful, colorless, transparent needles. 
These, though very easily soluble, are not deliquescent. They 
fuse above 200°, but undergo decomposition before the fusing 
point is reached. The meta-acid is deliquescent. 
Potassium Parasulphobenzoate, prepared by neutralizing and 
precipitating the acid barium salt by means of a solution of 
pure potassium carbonate, is exceedingly easily soluble in 
water, but crystallizes finally in well-formed, transparent 
needles, 
+ 2 
Acid sodium parasulphobenzoate, C*H* et reerg + 24H70. 
This salt was prepared by neutralizing and precipitating the 
acid barium salt with sodium carbonate, and ia adding 
hydrochloric acid to the solution, evaporating and allowing to 
crystallize. It forms beautiful, long, colorless, lustrous, stellate 
prisms. Jt is moderately easily soluble in cold water, more 
easily in hot water. The corresponding salt of the meta-acid is 
more difficultly soluble in cold water, and crystallizes in lam- 
Ine, e two, when present in the same solution, can not, 
however, be separated. The analysis of the salt gave the fol- 
lowing results : 
03707 grams of the salt, dried over sulphuric acid, on bein 
heated gradually to 310°, lost 0°0607 grams in weight; an 
then gave 0-102 grams Na2SO+=0-033038 grams Na. 
Calculated. Found. 
(C7H5S05) 201 = 74°72 
Na 3 8°55 8°91 
24H2O0 45 16°73 16°37 
269 100°00 
_ The remarkable fact will be noticed that the water of crystal- 
lization is not driven off entirely until a high temperature (320°) 
1s reached. All other salts of this acid, as well as of the meta- 
acid, which contain water of crystallization, oe the same 
property, though not in such a marked degree as this one. 
Biiss pce te, C7H*SO*. Ba+2H20. This salt 
Was obtained by neutralizing a solution of the acid salt with 
barium carbonate. It is moderately easily soluble in cold 
Water, very easily in hot water. It crystallizes in small needles, 
which are grouped together in verrucous m 1e corre 
sponding salt of the meta-acid is also easily soluble in water, 
Am. Jour. on tee Vou. V, No. 28.—ApriL, 1873. 
