288 MACERATION AND DIGESTION. 



of 40 to 50 C. may be sufficiently complete in an hour 

 (GAGE). 



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

 Ueber die peripherischen Endorgane, &c., 1862 ; RANVIEE, 

 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. 



546. Sulphuric Acid (RANVIEE, Traite, p. 78). Sulphuric 

 acid has been employed by Max Schultze for isolating the 

 fibres of the crystalline. 



Macerate for twenty-four hours in 30 grins, 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). 



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

 trated solution of oxalic acid has been found useful in the 

 study of nerve- endings. 



548. SCHIEFFEEDECKEE'S Methyl Mixture (for the retina) 

 (Arch.f. mik. Anat., xxviii, 1886, p. 305). -Ten parts of gly- 

 cerin, 1 part of methyl alcohol, and 20 parts of distilled water. 

 Macerate for several days (perfectly fresh tissue). 



Digestion. 



549. BEALE'S Digestion Fluid (Archives of Medicine, i, 1858, 

 pp. 296 316). The mucus expressed from the stomach 

 glands of the pig is rapidly dried on glass plates, powdered, 

 and kept in stoppered bottles. It retains its properties for 

 years. Eight tenths of a grain will dissolve 100 grains of 

 coagulated white of egg. 



To prepare the digestion fluid, the powder is dissolved in 



