376 APPENDIX. 



must be entirely removed from the sections by abso- 

 lute alcohol. 



Iodine. 



Dissolve 2 grms. of iodide of potassium in 100 c.c. of 

 distilled water, and add flakes of iodide to slight 

 excess. 



Gold chloride. 



The method of using this for ordinary cases is suffi- 

 ciently described in the Text, Less. iv. § 3 ; Less. 

 XXIV. A, § 4. The tissue should be touched with 

 metal as little as possible, it may be removed from 

 one fluid to another with a small brush. In cold 

 weather it is well to place the acidulated water with 

 the tissue in a glass chamber kept at 20 — 30° C. 



The following methods are advantageous in particular 



cases. 



a. Place the piece of tissue, which should be small, in 

 rather strong formic acid (1 vol. formic acid 1-16 

 Sp. Gr. and 3 or 4 vols, water) for a few minutes 

 until it is fairly transparent throughout, then place 

 it for about 20 minutes in 1 p. c. gold chloride, wash 

 it well with water; then place it in formic acid 

 diluted with three vols, water and leave it in the 

 dark for a day. The formic acid should be renewed 

 once or twice in the flrst two or three hours. After 

 the tissue has been placed in gold chloride it should 

 be exposed to light as little as possible. When the 

 tissue is stained it should be well washed with water 

 and mounted in formic glycerine. (Lowit.) 



