The object of this paper is to call attention to some of the chemistry of the methyl alcohol stains in common use for the staining of blood, and to point out the practical value of the study to the general practitioner who makes his own blood examinations.
Since Wright's modification is that in most common use, the discussion will be confined to it in the first part of the paper, though the remarks apply equally well to the Hastings modification and to the Harlow stain, which will be taken up in some detail later.
None of the polychrome methylene blue and eosin mixtures are stable. They are mixtures of polychrome methylene blue, which is both neutrophilic and basophilic, and of eosin, an oxyphilic stain. The specificity of the stain depends alone on the balanced combination of these two components, and this, in turn, depends on the reaction. Methyl alcohol is