V.—A method of preparing Strychnia. By J. T. Pearson, Esq. Assistant Surgeon.
The enormous price of 120 rupees having been paid at the Hon'ble Company's Dispensary for a single half ounce of strychnia; it became my duty to attempt to prepare it, by a process, more expeditious and less expensive, than that recommended in the formulary of Magendie[1]; and which, at the same time, should be equal to the demands made upon the department. I hope that both these objects have been effected by the following method:
Infuse a determined quantity of Nux Vomica in boiling distilled water, until it becomes soft; take it from the liquid, bruise it coarsely in a large metal mortar, and treat it with successive infusions of boiling distilled water, till it becomes nearly tasteless. Strain the liquids, and having mingled them together, boil with calcined magnesia for half an hour, and collect the precipitate upon a filter of fine muslin. When the precipitate has become free from the liquid, wash it gently, twice, as it lies on the filter, with cold distilled water, and afterwards dry it upon a water bath.
Treat the precipitate, dried as above-mentioned, with successive portions of boiling alcohol, sp. g. .838, or stronger, until it becomes quite exhausted, then mix the whole of the filtered alcoholic liquid, and evaporate in a water bath, till a thick crust forms upon the surface; set it aside to crystallize for twelve hours; pour off the mother waters, and collect and dry the strychnia upon filtering paper.
In this state, the strychnia is in small, but by no means microscopic, irregular crystals, of a light-brown colour; and it may be purified by redissolving and re-crystallizing it in boiling alcohol, or by pouring over it portions of rectified æther.
- ↑ The following is the process given by Magendie. "Add a solution of liquid subacetate of lead to a solution of alcoholic extract of the Nux Vomica in water until no more precipitate be thrown down; the foreign matters being thus separated, the strychnine remains in solution, with a portion of colouring matter, and sometimes an excess of acetate of lead. Separate the lead by sulphuretted hydrogen, nitrate it, and boil with magnesia, which will unite with the acetic acid, and precipitate the strychnine. Wash the precipitate in cold water, redissolve it in alcohol, to separate the excess of magnesia, and by evaporating the alcohol, the strychnine is obtained in a state of purity. If it be still not perfectly white, it must he redissolved in acetic or hydrochloric acid, and reprecipitated by means of magnesia." To prepare the alcoholic extract, the Nux Vomica must be rasped and exhausted by repeated macerations in alcohol, which must then be evaporated; a process the tediousness of which can only be duly appreciated by those who have tried it, and which it was my object to avoid.
