ABSTRACT
The usefulness of the process of staining tissues with several dyes has been abundantly proved. The general effect aimed at is the staining of each separate part in a different colour, so that for the purposes of histological demonstration each shall be distinct and clear. In the use of certain of the most commonly employed and easily manipulated dyes, e. g. hematoxylin and picrocarmine, it is believed that a definite effect may be always calculated upon when they are used in combination. With anilin stains, however, the results arrived at appear to differ very materially if the methods of employment are made to vary in even a very slight degree, and this has been one of the causes of the restricted use of very beautiful staining colours. It has been shown by several experimenters that with combinations of anilin colours, there is a tendency at any rate for certain dyes to pick out and stain different parts of a tissue; but I think I am right in believing that no certain result has hitherto been expected, except in the case of a very few combinations.
