§ 478. Commercial Veratrine.—Commercial veratrine is a mixture of alkaloids, and has usually fairly constant properties, one of which is its intense irritant action on the nostrils. Placed on moist blue-red litmus paper it gives a blue spot. It is but little soluble in water, 1 : 1500; but readily dissolves in alcohol and chloroform; it is but little soluble in amyl alcohol, benzene, and carbon disulphide.
When a very small quantity is treated with a drop of sulphuric acid, the acid in the cold strikes a yellow colour; on warming, the colour becomes violet, slowly changing to orange and cherry red. Sensible to 100th of mgrm. If this test is performed in a test-tube, a green-yellow fluorescence is also seen on the sides of the test-tube.
Commercial veratrine strikes a pink-red colour with hydrochloric acid in the cold if a long time is allowed to elapse, but it at once appears if the acid is warmed, and is permanent. The solution becomes fluorescent if two drops of acetic acid are added.
If a small quantity of commercial veratrine is added to melted oxalic acid and the warming continued, a blood-red colour is obtained.
Veratrine, warmed with syrupy phosphoric acid, develops an odour of butyric acid.
A dark green colour, followed by reddish purple and blue colours, is obtained by adding a sprinkling of finely-powdered sugar to a solution of veratrine in sulphuric acid. This is best seen with a solution of 1 to 10,000; if in dilution of 1 to 100,000 a grass-green colour is produced, followed by purple and blue colours, quickly changing to brown or black.[529]
[529] Flückiger’s Reactions, 1893.