APPENDIX. 183 



Cellulose-test. Saturate the object in iodine solution, wash in 

 water, and place it in strong sulphuric acid prepared by carefully 

 pouring 2 volumes of the concentrated acid into 1 volume of water. 



Collodion and Clove-oil. Used for fixing sections to the slide in 

 order to prevent the displacement of delicate or isolated parts in 

 balsam-mounting. Mix one part of ether-collodion and three parts 

 of oil of cloves. In mounting, varnish a slide with the mixture 

 by means of a camel's-hair brush, lay on the sections, and place the 

 slide for a few minutes on the water-bath (i. e. , until the clove-oil 

 evaporates). Transfer the slide to a wide-mouthed bottle of tur- 

 pentine (to dissolve the paraffin), remove it and drain off the tur- 

 pentine, place a drop of Canada balsam on the middle of a cover- 

 glass, and invert it over the object. 



Eosin. Dissolve in water until a bright-red solution is obtained. 

 It should be diluted when used. 



Glycerine, dilute. Two parts glycerine, one part distilled water. 



Hsematoxylin (Grenadier's). Add 4 c.c. of saturated alcoholic 

 solution of hsematoxylin to 150 c.c. of strong aqueous solution of 

 ammonia-alum ; let the mixture stand a week or more in the light, 

 filter, and add 25 c.c. of glycerine and 25 c.c. of methyl alcohol. 

 The fluid improves greatly after standing some weeks or months. 



Haematoxylin (Kleinenberg's). To a saturated solution of cal- 

 cium chloride in 70$ alcohol add an excess of pure alum ; filter 

 after 24 hours and add 8 volumes of 70$ alcohol, filtering again if 

 necessary. Add a saturated alcoholic solution of hsematoxylin 

 until the liquid becomes purple-blue. The longer the liquid stands 

 before using, the better. It should be diluted for use with the 

 alum-calcium-chloride solution in 70$ alcohol. 



Iodine Solution. Dissolve potassium iodide in a small quantity 

 of water, add metallic iodine until the mixture assumes a dark- 

 brown color, and then dilute to a dark-sherry color. The solution 

 should be kept from the light. 



Magenta (Aniline Red). Dissolve in water. ' 



Methyl Green. Used in aqueous or alcoholic solution. 



Normal Fluid (Normal Salt Solution). Dissolve 6.75 grams of 

 sodium chloride in 1 litre of distilled water. 



Paraffin. " Hard " and " soft " paraffins, i.e., those of high and 

 low melting-points, should be mixed in such proportions that the 

 melting-point lies between 50 and 55 C. 



Perenyi's Fluid. Ten-per-cent nitric acid 4 parts, 90$ alcohol 

 3 parts, $ aqueous solution of chromic acid 3 parts. Not to be 

 used until the mixture assumes a violet hue. Leave objects in the 



