162 Proceedings of the Royal Society 
very bitter, non-persistent taste. Concentrated nitric, hydrochloric, 
and sulphuric acids change its colour to brown, but these in a 
diluted state, as well as many of the organic acids, form pale, yel- 
lowish solutions with Akazgia. It is precipitated from these solu- 
tions by hydrate, carbonate, and bicarbonate of sodium, and of 
potassium ; by iodide, sulphocyanate, ferrocyanide, and chromate 
of potassium ; by phosphate of sodium, protochloride of tin, tri- 
chloride of gold, dichloride of platinum, potassio-mercuric-iodide, 
carbazotic acid, tincture of galls, solution of iodine, and various 
other substances, but these precipitates are never crystalline. Cor- 
rosive sublimate causes an amorphous white precipitate, which is 
dissolved by heat, and reappears in a non-crystalline form when 
the solution has cooled. Chlorine produces an amorphous, colour- 
less precipitate, which does not disappear on the addition of 
ammonia. With concentrated sulphuric acid, and peroxide of 
manganese, bichromate of potassium, or any other of the usual 
oxidizing agents, the same succession of colours is produced, from 
blue to brown, which results from a similar treatment of strychnin. 
The alcoholic extract of Akazga possess physiological properties 
very similar to those of nnx vomica; and comparative experiments 
were detailed, to show that the active principle, Akazgia, has 
exactly the same actions as the extract, and a proportional activity 
to it. 
There are several instances in which a Natural Order produces 
several very similar active principles. In the Loganiacese itself, 
strychnia, brucia, and igasuria already exist, and these are nearly 
identical in their physiological actions. In chemical properties, 
brucia and igasuria have much in common, and they are both 
readily distinguishable, in this respect, from strychnia. Akazgia 
conveniently completes this group, as its chemical properties are 
nearly allied to those of strychnia, whilst its connection with all 
the numbers is maintained by the similarity of its physiological 
actions. 
