138 NATURALISTS’ ASSISTANT. 
mixed with about one-third its bulk of ordinary hematoxylin solution, 
the connective tissue corpuscles are stained a beautiful purple. 
Miiller’s Fluid. 
Sulphate of soda I part. 
Bichromate of potash 2 parts. 
Water 100 parts. 
Miiller’s fluid for hardening the retina. 
Bichromate of potash 24 grammes. 
Sulphate of soda I gramme. 
Distilled water I0O grammes. 
Besides its hardening properties, this is useful for preserving glands, 
mucous membranes and ciliated cells. 
Bichromate of potash for macerating specimens is used in a % per 
cent. aqueous solution. 
Todized serun. 
Take the amniotic fluid of a cow or other mammal, add a crystal or 
two of iodine and allow it to stand a few days, with frequent agitation. 
Then filter. Any other serous fluid may be used. Jodized serum seems 
to macerate tissues and at the same time to preserve the original form of 
the histological elements. The iodine tends to prevent putrefaction 
and at the same time renders the elements of the tissue firmer. 
Artificial todized serum. 
Take one ounce of the white of an egg; pick out the chalazez and 
mix with nine ounces of water and fifty grains of common salt. Then 
add several crystals of iodine. 
Neutral salt solution isa 4 per cent. solution of common salt in dis- 
tilled water. It is useful in studying living tissues as the cells do not 
exhibit such marked changes as when pure water is used. 
Glycerine jelly. 
Cooper’s gelatine I 02. 
Best glycerine 6 oz. 
Carbolic acid 20 drops. 
