THE action of fuming sulphuric acid upon cinnamic acid was first thoroughly studied by Rudiiew, l who isolated from the sulphonation mixture, two acids: one, the now well-known p- sulphocinnamic acid, which is the principal product of the reaction; and the other, an isomer which he called a meta-compound. Since that time the true w-sulphocinnamic acid has been prepared synthetically by Kafka, 2 and as its properties do not agree with those of the acid ...
