This note refers to those anilin dyes which may be used for coloring specimens prepared by the celluloid injection method.
In a study of the anatomic relations of the salivary glands, it became of interest to inject simultaneously the gland substance through the excretory duct, and the arterial blood supply through the common carotid artery. The red dye used for the injection of the arteries is the usual substance employed for this purpose, namely, alkanin. This material in various dilutions does not afford a sufficient contrast for the study and comparison of the small excretory ducts and the capillaries. The gross relationship is more clearly indicated when two colors are used. The difficulty seems to be due to the necessity of macerating the injected specimens in concentrated hydrochloric acid, and subsequently washing away the débris. In this manner, the injected masses are freed from the overlying hard and soft tissues.