Gauthier suggests the addition of one drop of a one-per-cent solution of nitroglycerin to the quantity injected and repeated to prevent the unfavorable after effects.
Solutions of cocain are to be made up fresh each day, as they become moldy on standing. They cannot be sterilized, for the reason that a temperature of 213° F. renders them useless. The solution is most active at 50° F. (Costa).
For hypodermic purposes two- to ten-per-cent solutions are employed, the four per cent being more generally used, not more than 0.1 gram of the agent being introduced (Hänel, ano).
Fig. 34.—Simplex Syringe.
Fig. 35.—Kolle Improved Pravaz Syringe.
Fig. 36.—“Sub-Q” Syringe.