F. E. HOGGAN ON HISTOLOGICAL STAINING. 181 



and other conditions of the cell. A bluish tint may be given to 

 them by washing the section with an alkaline water ; the household 

 water of London, containing lime, is suitable for this kind of tinting. 



This process is especially useful for photographic purposes, and 

 to those who can only work with the microscope in artificial light, 

 the definition being very clear and distinct. It is probably the best 

 process for staining silvered preparations, as it has no effect on the 

 black lines, while it makes the nuclei very distinct. 



I have advised that the solution be filtered upon the preparation. 

 This, although unnecessary with clean fresh solutions, obviates any 

 chance of foreign matter becoming deposited on the preparation. It 

 is easily effected by taking a piece of blotting paper about two inches 

 square, folding it twice, and pouring into one of the cavities thus 

 formed about a teaspoonful of either solution, or more, according to 

 the size or number of the materials to be stained. 



The whole process is speedy, simple and permanent. The stain- 

 ing may be accomplished in five minutes, and the staining materials 

 can be bought at any country druggist's shop. The filtering paper 

 should be held with forceps to avoid staining the fingers, as the stain 

 is difficult of removal except with the binoxalate of potash. 



