AXIS-OYLlNDEIi AND DENDUITE STAINS. 435 



832. WOLTER'S Chloride of Vanadium process (Zeit. wiss. 

 Mik., vii, 1891, p. 471) : 



The material (either central or peripheral nervous tissue) 

 is hardened in the bichromate liquid of KULTSCHITZY, 55, 

 followed by alcohol, as there described. Sections are mor- 

 danted for twenty-four hours in a mixture of 2 parts of 10 

 per cent, solution of chloride of vanadium and 3 parts of 

 3 per cent, solution of acetate of aluminium, washed for ten 

 minutes in water, and stained for twenty-four hours in a 

 solution of 2 grins, of hsematoxylin (dissolved in a little 

 alcohol) in 100 c.c. of 2 per cent, acetic acid. They are 

 washed out until they are of a light blue-red colour in 80 per 

 cent, alcohol acidulated with 0*5 per cent, of hydrochloric 

 acid. Remove the acid thoroughly by washing with pure 

 alcohol, dehydrate, clear with origanum oil, and mount. 



Chiefly an axis-cylinder stain, myelin being coloured only 

 if the differentiation in the acid alcohol is insufficient, but 

 cells are also stained. 



833. Methylen Blue. MEYER (Arch. mik. Anat.,x.lvi, 1895, p. 282, 

 and xlvii, 1896, p. 734) has obtained good results (for the central nervous 

 system, not for the peripheral) by means of subcutaneous injection. 

 Large quantities of solution must be injected, in several portions, at 

 intervals of one to several hours. After some time the organs should be 

 thrown direct into the bath of BETHE, 344, and remain in it till the 

 next day. 



RAMON Y CAJAL (Rev. Trim. Micr., Madrid, i, 1890, p. 123 ; Zeit. wiss. 

 Mik.,x.iv, 1897, p. 92) stains by "propagation" or '' diffusion." The" 

 brain is exposed (rabbit) and the cortex is divided into slices of a couple 

 of millimetres thickness by means of a razor. The slices are then 

 covered on both sides either with finely powdered methyleii blue, or 

 with a saturated solution of the same, the slices are replaced in their 

 natural positions, the brain case is replaced for half an hour, after 

 which the slices are removed and fixed for a couple of hours with Bethe's 

 ammonium molybdate, washed, hardened for three or four hours in a 

 mixture of 5 parts 1 per cent, platinum chloride, 40 parts f orniol, and 60 

 parts water, further treated for a few minutes with platinum chloride 

 in alcohol (1 in 300), and if small enough imbedded in paraffin. The 

 sections should be dehydrated with alcohol containing 0'3 per cent, of 

 platinum chloride, and may be cleared with xylol or bergamot oil and 

 mounted. The stain is stronger and more complete than that of the 

 other methylen blue methods. 



CATOIS (Comptes Rend., cxxiv, 1897, p. 124) injects con- 



