608 JAMES W. BARRETT. 
mately, following the usual plan, it should be transferred, first 
to weak, and subsequently to strong alcohol. Much of the 
success of the process is dependent on the care taken in 
fixing and hardening. Although any of the chromic acid 
preparations harden very well indeed, yet there are two 
important objections to their indiscriminate use as fixing or 
hardening agents,—they usually render the lens brittle and 
unnecessarily hard, and they often render the sections difficult 
to stain. Therefore, another fixing agent has been employed 
when I have wished to prepare sections of the lens or to stain 
the eye thoroughly. This agent is carbolic acid. The eyes 
after removal from the body should be placed in a 2 per 
cent. watery solution for a week, and should then be trans- 
ferred to alcohol and be treated as in the former case. When 
prepared in this way the eyes stain readily and the lens is not 
usually brittle. 
If a section of the eye without the lens is required it is 
better to use a chromic acid hardening solution, because that 
reagent hardens so satisfactorily. 
The eye hardened by any of these methods should be stained 
in bulk; this is not absolutely necessary, for sections may be 
stained after they have been cut, but staining in bulk enables 
one to avoid a certain amount of dangerous after-manipulation. 
Before placing the eye in the stain four small openings 
should be made in it, two into the anterior chamber, and two 
into the vitreous. The openings into the anterior chamber 
should be situated opposite to one another, and at the peri- 
phery ; those into the vitreous should also be opposite one 
another, and should be situated midway between the cornea 
and the entrance of the optic nerve. 
The only stain which was found to be reliable for staining in 
bulk was borax carmine (alcoholic). Kleinenberg’s logwood 
will not penetrate sufficiently, and (in my hands) often fails to 
select ; and most of the aniline stains (which penetrate admir- 
ably) are partially removed during the necessary after-treat- 
ment. 
The eye should be left in the stain for from two to four days, 
