246 ' MACERATION CORROSION 



568. Osmic and Acetic Acid (the Hertwigs, Das Nerven- 

 sijstem u. die Sinnesorgane der Medusen, Leipzig, 1878, and Jen. 

 Zeitschr., xiii, 1879, p. 457). 



0-05 per cent, osmic acid ... 1 part, 

 0-2 ,, acetic acid . . . 1 ,, 



Medusa; are to be treated with this mixture for two or three 

 minutes, according to size, and then washed in repeated changes 

 of 0-1 per cent, acetic acid until all traces of free osmic acid are 

 removed ; they then remain for a day in 0-1 per cent, acetic 

 acid, are washed in water, stained in Beale's carmine, and 

 preserved in glycerin. 



For Actinia; the osmic acid is taken weaker, 0-04 per cent. ; 

 both the solutions are made with sea water ; and the washing out 

 is done with 0-2 per cent, acetic acid. If the maceration is com- 

 plete, stain with picro-carmine ; if not, with Beale's carmine. 



569. MoBius's Media {Morph. Jahrh., xii, 1887, p. 174). 



1 . One part of sea water with 4 to 6 parts of 0-4 per cent, sohition of 

 bichromate of potash. 



2. 0-25 per cent, chromic acid, 01 per cent, osmic acid, 01 per cent, 

 acetic acid, dissolved in sea water. For Lamellibranchiata. Macerate 

 for several days. 



570. 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. Pre- 

 parations may afterwards be washed with water and put up in 

 strong solution of alum, in which they may be preserved for a 

 long time (Hopkins, Proc. Amer. Soc. of Microscopists, 1890, 

 p. 165). 



Maceration is greatly aided by heat, and at a temperature of 

 40° to 50° C. may be sufficiently complete in an hour (Gage). 



A mixture of equal parts of nitric acid, glycerin and water is 

 recommended by Marcacci {Arch. Ital. Biol., iv, 1883, p. 293) 

 for smooth muscle. 



571. Nitric Acid and Chlorate of Potash (Kuhne, JJeher die 

 peripherischen Endorgane, etc., 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. 



572. Nitric and Acetic Acid (Apathy, Zeit. iviss. Mik., x, 1898, p. 49). 

 3 volumes glacial acetic acid, 3 of nitric acid, and 20 each of water, 

 glycerin, and absolute alcohol. Macerate leeches for twenty-four hours, 

 and bring them into 70 per cent, alcohol, in which they swell ; then 

 after twenty-four hours, 50 per cent, glycerin, changed till the acid is 

 removed. 



