CORPUSCLES OF HBBBST AND OP GRANDRY. 293 



by imbedding in pith and cutting with a knife wetted withr 

 alcohol) as there described. 



616. Tactile Corpuscles (FISCHER, Arch.f. mik. Anat., 1875, 

 p. 366). Fischer employed the gold-method of Lowit, see 

 207. Ranvier (Traite, p. 918) also recommends this method, 

 as well as his two gold-methods, Nos. 208, 209. Pieces of 

 skin are first impregnated whole, then hardened by alcohol, 

 and sectioned. He finds (as do other authors) that osmic acid 

 and picro-carmine are invaluable aids to the study of these 

 structures and to that of the corpuscles of Pacini. Purpurin 

 and haematoxylin may also be used for after-staining. See 

 RANVIER, Traite, p. 919. 



617. Tactile Corpuscles and Rete Malpighi (LANGERHANS, 

 Arch.f. mik. Anat., 1873, p. 730). Pieces of fresh skin are 

 placed for twenty-four hours in a large quantity of J per cent, 

 osmic acid, and are then found to be both stained and hardened 

 to the right point for cutting sections. 



618. Corpuscles of Herbst and Corpuscles of Grandry (CARRIERE, 

 Arch.f. mik. Anat., 1882, p. 146). Take fresh beaks of ducks, 

 remove the skin and papillae from the margins, and put pieces 

 for twenty-four hours into 1 per cent, osmic acid, wash in 

 water, and put into 90 per cent, alcohol : or put them at once 

 into alcohol (40 per cent, for a few hours, then 70 per cent., 

 then 90 per cent.). The latter are made into sections and 

 stained with neutral carmine, picro-carmine, f uchsin, or haema- 

 toxylin. The last gives the best results. Or, the pieces of 

 skin are treated as follows : 



Formic acid (50 per cent.) twenty minutes or until trans- 

 parency is attained ; remove the corneous layer of epithelium ; 

 rinse in water ; gold chloride 1 per cent, (twenty minutes) ; 

 rinse in water; Pritchard's solution (amyl-alcohol 1 per cent., 

 formic acid 1 per cent., water 98 per cent.) from mid-day till 

 next morning (in the dark) ; rinse in water; treat with alcohol ; 

 imbed in paraffin, and make sections. 



It is important to take only small quantities of gold 

 chloride, not more than about 10 c.c. of the solution to 

 "quite a number" of pieces of skin and papilla3. On the 

 other hand, large quantities of Pritchard's solution should be 

 employed. 



