PREPARATION OF EYE FOR HISTOLOGICAL EXAMINATION. 6138 
6. After staining, the eye is placed in a mixture of alcohol 
and ether, equal parts, for twenty-four hours, and is then sub- 
mersed in pure chloroform for two days. It is finally placed 
in melted paraffin for twelve to forty-eight hours, and is 
treated subsequently as in the former case. By the use of 
chloroform the treatment with turpentine and oil of cloves is 
avoided. 
Conclusions.—1. Satisfactory sections of a small portion 
of the eye may be easily obtained by infiltrating and embedding 
in celloidin, and by cutting sections either with the freezing 
microtome or under spirit. Such sections may, if necessary, 
be stained after they have been cut. 
2. Sections of parts of the eye without the lens of young or 
of embryonic eyes may be readily obtained by infiltrating and 
embedding in paraffin by the chloroform process. The eye 
must in this case be stained in bulk. 
3. Sections of the eye with the lens in sitt may be best 
procured by infiltrating and embedding in celloidin and cutting 
under spirit. 
If sections of the Classes 1 and 2 are required I believe that 
it is better to harden the eyes in chromic acid, but if sections 
of Class 3 are in demand the fixation and hardening should be 
effected by the use of alcohol and carbolic acid. 
PREPARATION OF RETINA. 
When I first endeavoured to prepare sections of retina I 
had to determine :— 
a. The best fixing and hardening agent. 
b. The best staining agent. 
c. The best embedding agent. 
(a2) I obtained many eyes from guinea-pigs, fixed and 
hardened them in different solutions, and prepared sections 
of the retina. But except in the matter of hardening all 
were prepared in the same way, so that in the fixing and 
hardening the only variable factor was consciously intro- 
duced. 
