IN USE AT THE ROYAL BOTANIC GARDEN. 235 
2.—Methods which render the specimen flaccid. 
a. Bleaching Solution. 
This is the most rapid and effective bleaching agent. Its 
macerating action is considerable, and it should not be employed 
when dealing with the more delicate specimens. The specimen 
is transferred from the strong alcohol and placed for several 
hours in alcohol of 50 per cent., from this it is transferred to 
water, and shortly after to a weak solution of ordinary bleaching 
powder. This solution is prepared by pouring warm water over 
bleaching powder and filtering. 
After remaining in the bleaching solution for from 5 to 15 
minutes, the specimen is transferred to a 2 per cent. by volume 
solution of hydrochloric acid in water. As the weak acid 
penetrates, it sets free the chlorine, which is 2 brought into 
intimate contact with the substances to be bleached. If the 
specimen after some time is not sufficiently eae it is replaced 
in the bleaching solution, and similarly a second time transferred 
to the acid. This is repeated as often as is DECESSALY until 
bleaching is complete. 
After bleaching, the specimen is placed in water, and from this 
it is graded to go per cent. alcohol, 
The corresponding hypochlorites of sodium and potassium, 
“Eau de Labarraque” and “ Eau de Javelle,’ are also powerful 
bleachers, breaking up on the addition of acid and setting free 
chlorine in the same manner as the hypochlorite of calcium. 
These also have a marked macerating action on the tissues. 
6. Warm Water and Acid. 
Nitric acid or hydrochloric acid 5 per cent. 
The specimen is graded from the strong alcohol to water, and 
is from that transferred to a warm aqueous solution of hydro- 
chloric acid or even to warm water alone. 
After some hours it is again transferred by slow grading to 
strong alcohol and left to the action of sunlight. 
The macerating is less than results from the eniployment ot 
bleaching powder, but the bleaching is not so rapid. 
