Chemistry. — “On the Acceleration of Solubility of Metals in 
Acids by Reducible Compounds.” By H. J. Prins. (Communi- 
cated by Prof. J. BöesEKEN.) 
(Communicated at the meeting of March 26, 1921). 
It is a well-known fact that though there are a great many means 
available for the reduction of organic compounds, the choice of the 
reducer greatly contributes to the success of the reduction, so that 
it is not sufficient to bring hydrogen in status nascens in the presence 
of the substance that is to be reduced. It ensues from this that there 
must be a relation between the reducer and the compound that is 
to be reduced; if this relation were known it would be possible to 
make a choice with certainty from the available reducers for a 
definite purpose, or to find new reducers. 
Some years ago it was pointed out') that in case of reductions 
the velocity of solubility of the metal in the acid is enhanced by 
the reducible substance, and that evidently a cooperation, a coaction 
must take place between metal, acid, and reducible compound in 
order to bring about the reduction; which is then accompanied by 
a more rapid dissolving of the metal. 
Definite examples of this have not been recorded, except in the 
literature *) of patents. 
Such coactions, which are reckoned among the mutual inductions, 
are however, known in all kinds of other reactions, especially oxi- 
dation reactions. Besides it is known that metals dissolve more 
rapidly in the presence of oxidizers,*) in such cases it is, however, 
difficult to decide, whether one bas to do with a mutual induction 
or a subsequent reaction, while the formation of primary oxides 
assumed by some scientists to take place in such reactions as inter- 
1) Prins, Chem. Weekbl. 14, 72 (also note) and id. 1004 (1917). 
Ibid 11, 476, 477 (1914). 
Ibid 12, 38 et seq. (1915). 
Journ. f. prakt. Chem. N. F. 89. 448 et seq. (1914). 
7) LASSAR Coun, Arbeitsmeth. d. org. Chem. 
3) Van Name, Chem. Gentr.bl. (1914). I 20; (1918). 1 257, 907. 
Satkowski, Chem. Ztg. 40. 448 (1916). 
