derived from Indigo-blue. 307 



different product is obtained — a product which differs from 

 the other by its solubility in ether, and its total insolubility 

 in alkalies, and shows a striking resemblance to the body A, 

 which is also soluble in ether and insoluble in alkalies. Still, 

 as my process was conducted in open vessels and not under 

 pressure, I think it is not probable that any of this substance 

 was formed*. 



2. From what has been stated above, it follows that all the 

 products, except anthranilic acid, are formed by a very simple 

 process, which consists merely in indigo-blue combining with 

 alcohol and acetic acid in various proportions, and yielding 

 compounds in which none of the constituents as such can be 

 detected. It is, therefore, not a process of decomposition, but 

 rather a synthetical process, a building up of complex bodies 

 from others of a simpler constitution. This is proved by the 

 fact of water being eliminated during the process, whereas in 

 all cases in which complex organic substances are decomposed 

 into simpler ones water is absorbed. This elimination of water 

 proceeds so far, that some of the products, notwithstanding that 

 they are formed by the addition to indigo-blue of many atoms 

 of alcohol and acetic acid (bodies having much less carbon and 

 more oxygen), are found to contain even more carbon than 

 indigo-blue itself, a great proportion of the water both of the 

 alcohol and the acetic acid having been separated. Is it not 

 possible that processes of a similar nature may go on within 

 the cells of plants, the chief function of which is known to 

 consist, chemically speaking, in the construction of complex 

 bodies from others of a simpler composition? Is not the 

 power residing in the vegetable cell which enables it to neu- 

 tralize very potent chemical affinities somewhat of the same 

 nature as that which, in this process, causes the acetic acid to 

 leave the strong base with which it is combined in order to 



* According to Liebig, the colour which an alcoholic solution of caustic 

 potash assumes in contact with the air is due to aldehyde-resin, the product of 

 decomposition formed by the action of caustic alkalies on aldehyde. Weiden- 

 busch (Annalen der Chemie u. Pharmacie, B. lxvi. S. 153), however, states that 

 the true aldehyde-resin is almost insoluble in alkalies ; and in consequence of the 

 discrepancy in the accounts of this body, I requested Mr. A. Mylius to make 

 some experiments on the action of caustic alkalies on alcohol in sealed tubes. He 

 obtained by this action a resin of a fine reddish-yellow colour, soluble in ether, 

 but totally insoluble in watery solutions of alkalies. Its properties so nearly 

 resemble those of the true aldehyde-resin, as described by Weidenbusch, and its 

 composition differs so little from that of the latter, that it seems very probable 

 that the two resins may be identical. If so, it follows that aldehyde-resin is 

 certainly formed by the action of caustic alkalies on alcohol, but only under 

 pressure in sealed tubes. The resin formed in open vessels in contact with 

 the air is totally different. For further particulars regarding this peculiar 

 action I must refer to the account of Mr. Mylius' s experiments contained in the 

 Proceedings of the Society, February 21st, 1865. 



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