I, Remsen on Parasulphobenzoic Acid. 275 
pleted in the course of a few minutes. The liquid becomes 
very hot and foams somewhat; an evolution of gas takes place 
as long as the oxidation-process continues; and its cessation 
indicates the end of the operation. In order to extract the 
product from the mixture the whole was diluted with a large 
amount of water, and chalk added to the point of neutraliza- 
tion. By this means the chromium oxide formed, and the 
rated almost to dryness. The colorless residue consisted of the 
potassium salts together with some potassium hydroxide. The 
mass was first neutralized with sulphuric acid, and then a suffi- 
cient quantity of the latter added to set the sulpho-acids free, 
care being taken to avoid any large excess. Moderately strong 
alcohol being now poured upon the mixture, an abundant 
deposite of ptassium sulphate took place. This was filtered off, 
the salt well washed out with alcohol, and the alcoholic filtrate 
evaporated down again to asmall volume. Potassium sulphate 
was again deposited. This was filtered off, washed out, etc., and 
the operation repeated a few times. Finally the alcoholic solu- 
tion was boiled for some time with water, and then evaporated to 
dryness over the water-bath. In this way the ep Gra were 
05415 grams salt were heated above 200°, and lost 0°0495 grams 
H?0; and gave 0°2130 grams BaSO*#=0"12524 
Calculated. Found. 
oO 
(C14H 1082010) 402 67°79 
Ba 137 23°10 23°13 
3H?0 54 9°11 9°14 
593 100°00 
This shows then conclusively that by the oxidation with sul- 
huric acid and potassium bichromate, the sulpho-group of 
Parasulphotoluenic acid remains intac of 
ortho-acid under like circumstances I shall to bel 
