1904 - 5 .] Crystallisation of Potassium Hydrogen Succinate. 451 
dish, elliptical in form, and growing in towards the centre. Their 
appearance was that of truncated cones. They were removed, and 
a month later a single elliptical biconical crystal was obtained ; it 
was brownish-yellow in colour, and resembled those obtained with 
chromic hydroxide, but was much more perfect in form. 
Chromic hydroxide dissolves in potassium hydrogen malate 
much more readily than in the corresponding succinate, and gives 
finally a very dark green solution, from which crystals similar to 
those already described have been obtained. 
I am continuing the investigation, and hope to be able to publish 
a detailed examination of these crystals at an early date. 
Chemical Laboratory, 
Surgeons’ Hall, Edinburgh. 
{Issued separately February 4 , 1905 .) 
