g6 CLINICAL BACTERIOLOGY AND H.EMATOLOGY 



staining. These are by no means difficult, though they are some- 

 what tedious. Two processes, both modifications of Gram's method, 

 will be given. They are not difficult to apply, but are very slow. 



Method of Staining Hairs, Scales, etc 



Requisites. — i. Aniline gentian violet, carbol gentian violet, or 

 carbol fuchsin. 



2. Gram's iodine solution. 



3. Aniline oil, to which a little strong hydrochloric acid has been 

 added, two or three drops to a quarter of a test-tube full of the oil. 

 Prepare when required, and shake. 



4. Aniline oil. 



5. Xylol. This is not necessary unless the specimens are to 

 be kept permanently. 



6. Blotting-paper. 



7. Slides, cover-glasses, and balsam. 



Process. — Take a broken hair or stump from the edge of the 

 suspected area, and cut off all the free portion, except a piece 

 about \ inch long. The root and the part of the shaft next 

 to it are all that are to be examined. Several of these hairs can 

 be stained at the same time. 



Stain in a watch-glass full of stain, or on a slide, for a quarter 

 of an hour, or longer — the longer the better ; it is an advantage to 

 warm the stain gently, and it will penetrate better if the hairs 

 have been previously washed in ether, though this is not absolutely 

 necessary. 



Remove the hairs from the stain, and place them on a slide ; if 

 already on a slide, pour off the stain. Dry them with blotting- 

 paper, and pour on the iodine solution ; allow it to act for five 

 or ten minutes. It is an advantage to blot the specimen after a 

 minute or two, and apply a fresh lot of the solution. Blot thoroughly. 



Now decolorize in the solution of hydrochlorate of aniline in 

 aniline oil. This should be poured off and replaced occasionally, 

 and the specimen examined under a low power of the microscope. 

 When the decolorization appears to be complete (it may take 

 many hours), pour off the solution and replace it by aniline oil ; 

 allow this to act for an hour or more, renewing it occasionally. 



If the specimen is not to be kept permanently it may now be 

 mounted in balsam and examined at once. If it is to be kept the 



