10 6 Mr. W. Brande's Chemical Researches on the Blood , 
the lilac tint disappears, and the mixture is only slightly 
green. 
When exposed to heat, the colour gradually changes as the 
acid becomes more concentrated by evaporation, and when 
reduced to about half its bulk the lilac hue is destroyed. 
The solutions of pure and carbonated alkalies when added 
in excess, convert the colour of this sulphuric solution to 
brownish red ; but in smaller quantities, they merely impair 
it by dilution. 
C. Nitric acid, even much diluted, is inimical to the colour- 
ing matter of the blood. 
A few drops added to the muriatic or sulphuric solutions 
gradually convert their colour to a bright brown, and larger 
quantities produce the same change immediately. 
The action which this acid exerts upon the colouring matter 
nnder other circumstances is nearly similar, and always at- 
tended with its decomposition, so that my attempts to procure 
a red solution in this menstruum uniformly failed of success. 
D. Acetic add dissolves a considerable quantity of the co- 
louring matter of the blood ; the solution is of a deep cherry 
red colour. When somewhat diluted, or when observed in 
tubes of about a quarter of an inch bore, this solution appears 
perfectly green by transmitted light. In its other habitudes 
4 t nearly resembles the muriatic solution. 
E. The solution of the colouring matter in oxalic acid is of 
a brighter red than those hitherto noticed ; that in citric add 
is very similar to the acetic solution, and with tartaric acid the 
compound somewhat inclines to scarlet. All these solutions 
exhibit the green hue, to which I have so often alluded, in a 
remarkable degree. 
