58 
Proceedings of Royal Society of Edinburgh . [sess. 
the resulting mixture, the whole of the- nickel goes into solution. 
Such solutions are, however, very unstable, and rapidly darken, 
owing to the formation of peroxide of nickel. Much more stable 
solutions of nickel can be obtained by using supersaturated solutions 
of sodium carbonate, prepared by subjecting decahydrated sodium 
carbonate to aqueous fusion. 
The author points out in this connection that bromine, does not 
liberate carbonic acid from such a supersaturated solution of sodium 
carbonate even when it is added in excess. Carbonic acid is, how- 
ever, given off freely on subsequent dilution with water. 
The author is at present investigating the action of bromine on 
sodium carbonate under varying conditions— (a) upon each other, 
( b ) upon mixed solutions of cobalt and nickel salts. 
His experiments, so far as they have gone, point to the possibility 
of effecting the separation of nickel from cobalt in a rapid and easy 
manner. 
On certain Substances found in the Urine, which reduce 
the Oxide of Copper upon Boiling in the presence of 
an Alkali.* By Herbert H. Ashdown, M.D. 
(From the Physiological Laboratory of University College, London, and the 
Laboratory of the Royal College of Physicians, Edinburgh.) 
(Read December 16, 1889.) 
(Abstract.) 
As the immediate. result of the ingestion of certain chemical com- 
pounds — chloral, camphor, benzol, phenol, &c. — substances make their 
appearance in the urine which have long been known to possess the 
power of reducing the oxides of some of the metals when in solution 
in the presence of an alkali, if that mixture be raised to the boiling 
point, but considerable confusion has resulted from the difficulty of 
finding a short process whereby many of these substances may be 
readily recognised as not belonging to that comprehensive group of 
conditions generally styled as glycosuria. 
The importance of this group has been greatly increased of late 
* A grant was given by the British Medical Association towards the 
expenses of this research. 
