A specimen naturally white in structure, may become changed to a dark color and be decomposing. To preserve such a specimen, there is no solution so good as the following:

4937

Alcohol (sp. gr. 0 830)......℥ x

Sulphurous acid.....to saturation

Put the alcohol in a flask, surround the flask with ice water, and then pass sulphurous acid gas, made by the action of strong sulphuric acid on copper turnings through the alcohol until bubbles begin to escape freely. After this take away the gas and close the flask containing the saturated alcohol securely. - Richardson.

corrosive; preserving solution. For the preservation and hardening of delicate soft structures, such as the brain and spinal cord.

4938

Corrosive sublimate.......gr. x

Alcohol (sp. gr. 0. 830)......℥ j

Acid hydrochloric (sp. gr. 1.16)....... .  x

Glycerin Zinc Solution. For preserving the brain in part or entire, or other nervous structures.

4939

Methylated spirit........℥ xx

Zinc chloride........ gr. xxx

Glycerin............℥ x

Dissolve the zinc chloride in the spirit and gradually add the glycerin. In use immerse the structure in the solution and keep it in until it is fully saturated. Then remove and let harden.