B06 History of Chemical Discoveries. 
and the decoction filtered and boiled for a few minutes with 
pure magnesia. It must then be refiltered, and tlie residuum 
left in the filter. After being well washed, it is boiled with 
highly rectified alcohol, which dissolves the alkali, and by eva^ 
poration it is obtained as a white pulverulent substance, pre- 
senting a few crystalline points. 
Pure delphine is crystalline while wet ; but becomes rapidly 
opaque when exposed to the air. It has a bitter acrid taste, 
melts by heat, and becomes hard and brittle like resin when 
cooled. By a greater degree of heat it blackens, and is decom- 
posed. Water dissolves a very small portion of it. Alcohol 
and ether dissolve it readily. The alcoholic solution renders 
.syrup of violets green, and restores the blue tint of litmus red- 
dened by an acid. It forms very soluble neutral salts with the 
acids. The alkalies precipitate it in a white gelatinous state like 
alum. 
Sulphate of Delphine does not crystallise, but by spontaneous 
evaporation dries into a hard transparent mass like gum. It 
has a bitter acrid taste, which continues many hours, and dis- 
solves readily in w'ater and alcohol. When the galvanic cur- 
rent is passed through a concentrated solution of it, the sulphu- 
ric acid is deposited at the positive pole, and the delphine at the 
negative pole, in white flocks. 
Nitrate of Delphine.^ formed by dissolving the delphine in 
weak nitric acid, is colourless. It assumes a yellovv^ colour by 
concentration ; and retains that colour, and has a crystalline ap- 
pearance when evaporated to dryness. When heated with an 
excess of acid, it is converted into a yellow^ matter, little soluble 
in water, and difficultly soluble in boiling alcohol. This solu- 
tion is bitter, and is not precipitated by potash, ammonia, or 
lime-water. Though not alkaline, it appears not to contain any 
nitric acid. It was not altered by farther quantities of acid, 
and no trace of oxalic acid ever appeared. 
Acetate of Delphine does not crystallise, but is converted by 
drying into a hard transparent mass, which has a bitter and 
acrid taste, and is readilv decomposed by cold sulphuric acid. 
Oxalate of Delphine crystallises in white plates, and p()sse.sscs 
the .same taste as the other salts of delphine, 
