1895.] MICROSCOPICAL JOURNAL. 341 



nail, the bed, the matrix, the subungual fold. With a 

 pointed scalpel circumscribe the tissues about tlie nail, 

 carfuUy grazing the bone. Place the whole in 90° alco- 

 hol (24 hours), then harden in gum and alcohol. Cut off 

 longitudal and transverse pieces ; place these in a micro- 

 tome, imbedding in cork, not in pitli. With a strong 

 razor cut the cork and the nail as if imbedded in pith. 

 It is necessary to keep the material well wet with alco- 

 hol while sectioning. Very thin sections are not needed; 

 stain picro-carraine, mount in neutral or in acid 

 glycerine. 



Nerve endings. — We shall successively study the intra- 

 epithelial nerve fibres, the corpuscles of Meissner and 

 those of Paccini. 



Intra-epithelial fibres. — From a perfectly fresh finger 

 take from the palmar surface of the 3d phalanx, a piece 

 of skin 1 or 2 mm. square. Removing the subcutaneous 

 cellular tissue, place the skiu in a mixture of gold clilor- 

 ide and formic acid (gold chloride, 1 per cent solution, 4 

 pts., formic acid, 1 pt.; boil and cool). In an hour trans- 

 fer to water slightly acetified, and having removed the 

 excess of gold, plunge rapidly in distilled water. Re- 

 duce the gold by day light (from 36 to 48 hours); place 

 the piece in strong alcohol. Section perpendicularly to 

 the surface. Mount in glycerine. 



Meissnefs corpuscles. — These may be well observed in 

 sections made after osmic acid and alcohol. We will de- 

 scribe other methods, as follows. 



A piece of skin from the pulp of the finger is put for 15 

 minutes in lemon juice. Wash ; put in gold chloride or 

 in the double chloride of gold and potassium for 1 hour. 

 The reduction is attained in slightly acetified water in 

 day light. This is accomplished very slowly (two or even 

 many days), so a more rapid method has been sought. 

 From the gold transfer for 12 to 24 hours to water ; warm 

 in a saturated solution of tartaric acid to 70° or 80° C. 



