138 NATURALISTS' ASSISTANT. 



mixed with about one-third its bulk of ordinary haematoxylin solution, 

 the connective tissue corpuscles are stained a beautiful purple. 

 Muller'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 2^ grammes. 



Sulphate of soda I gramme. 



Distilled water 100 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 j per 

 cent, aqueous solution. 



Iodized serum. 



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. Iodized 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 iodized serum. 



Take one ounce of the white of an egg; pick out the chalazese and 

 mix with nine ounces of water and fifty grains of common salt. Then 

 add several crystals of iodine. 



Neutral salt solution is a 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 oz. 



Best glycerine 6 oz. 



Carbolic acid 20 drops. 



