MICROSCOPICAL TECHNIQUE. 88 



dark purple. The solution may be concentrated by adding more 

 haematoxylin. For dilution, alum, chloral, and distilled water 

 answers best. 



Method of Examining Blood, Bone - Marrow,^— Although 

 Ehrlich's method preserves the characters of the red corpuscles 

 and fixes the hsemaglobin. Dr. R. Muir, finding that the structure 

 of the nuclei is not so well preserved by it, proposes the following 

 method : — -Films of blood are made on cover-glasses, as in 

 Ehrlich's method, care being taken to avoid pressure on the films. 

 They are then placed, before any drying can occur, film down- 

 wards, for about half-an-hour, on the surface of a saturated solution 

 of corrosive sublimate, with J per cent, sodium chloride added, 

 preferably heated to a temperature of about 50*^ C. (though this 

 latter is not essential). 



They are then thoroughly washed in J per cent, common salt 

 solution, taken through successive strengths of alcohol, and then 

 stained in the same way as sections. He also adds salt in the 

 same proportion to the weaker strengths of alcohol. In the case 

 of the bone-marrow, a little of the pulp is brought in contact with 

 a cover-glass once or twice, so as to make a layer, but it ought not 

 to be spread out — e.g., by a glass rod, as thereby the cells become 

 distorted. The cover-glass is then placed in the fixing solution. 

 Spleen pulp, the juice of the lymphatic glands of tumours, etc., 

 can be treated in the same way. The stains found most useful are 

 Ehrlich's acid, haematoxylin with aurantia or with eosin, saffranin 

 with aurantia, the triple stain of saffranin, hgematoxylin and 

 aurantia, and Biondi's triple stain. Dr. Muir states that he found 

 the method very useful for photographic purposes. 



Method of Preparing the Blood- Vessels of the Retina for 

 Lantern Demonstration.! — Dr. J. Musgrove has been experiment- 

 ing on the eye of the ox, and says that the eye should be obtained 

 within a short time of death. In removing the eye, as much as 

 possible of the fat and muscles of the orbit should be removed as 

 well, and the vessels cut far back. The injection is made through 

 the ophthalmic artery with an ordinary hand-syringe. Very good 



* Journ. Anat. and Physiology, Vol. xxvi. {1892), pp. 393, 394. 

 \Journ. Anat. and Physiology , xxvi. (1892), pp. 244 — 253. 



