SOHIEFFEEDECKKR'S MKTHYL MIXTURE. 245 



is complete, stain with picro-carmine ; if not, with Beale's 

 carmine. 



515. BELA HALLER'S Mixture (Morphol. Jahrb., xi, p. 321). 

 One part glacial acetic acid, 1 part glycerin, 2 parts water. 

 Specially recommended for the central nervous system of 

 mollusca (Rhipidoglossa) . A sufficient degree of macera- 

 tion is obtained in thirty to forty minutes, the cells showing 

 less shrinkage than with other liquids. 



516. Nitric Acid. Most useful for the maceration of muscle. 

 The strength used is 20 per cent. After twenty-four hours' 

 maceration in this, isolated muscle-fibres may generally be 

 obtained by shaking the tissue with water in a test-tube. 



517. Nitric Acid and Chlorate of Potash (KUHNE'S method, 

 Ueber die peripherischen Endorgane, 'fyc., 1862; RANVIER, 

 Traite,p. 79). Chlorate of potash is mixed, in a watch-glass, 

 with four times its volume of nitric acid. A piece of muscle 

 is buried in the mixture for half an hour, and then agitated 

 with water in a test-tube, by which means it entirely breaks 

 up into isolated fibres. 



518. Sulphuric Acid (RANVIER, Traite 3 p. 78). Sulphuric 

 acid has been employed by Max Schultze for isolating the 

 fibres of the crystalline. 



Macerate for twenty-four hours in 30 grammes of water, to 

 which are added 4 to 5 drops of concentrated sulphuric acid. 

 Agitate. 



ODENIUS found very dilute sulphuric acid to be the best 

 reagent for the study of nerve-endings in tactile hairs. He 

 macerated hair-follicles for from eight to fourteen days in a 

 solution of from 3 to 4 grains of "English sulphuric acid " to 

 the ounce of water. 



Hot concentrated sulphuric acid serves to dissociate horny 

 epidermic structures (horn, hair, nails). 



519. Oxalic Acid. Maceration for many days in concen- 

 trated solution of oxalic acid has been found useful in the 

 study of nerve-endings. 



520. SCHIEFFERDECKER'S Methyl Mixture (for the retina) 

 (Arch. f. mik. Anat., xxviii, 1880, p. 305). Ten parts of gly- 



