PREPARATION OF TISSUES. 225 



pud for removing sections from one fluid to another ; 

 sveral glass-rods or pipettes ; a dozen glass phial bottles 

 >r containing reagents and staining fluids ; glycerine ; 

 cetic acid,osmic acid, alcohol, methylated spirit, distilled 

 ater, &c. ; and lastly, a few camel's- hair brushes, watch- 

 lasses, and two or three porcelain capsules. All spirits 

 iould be kept in well-stoppered bottles. For dissec- 

 ions and the examination of small animals, or portions 

 f larger, and of tissues in general, a dissecting micro- 

 30pe fitted with two or three powers will be found 

 lost convenient. The method of teasing out with 

 eedles is shown in the annexed fig. 143^. 

 All animal tissues should be examined in as fresh a 

 iate as possible, and kept in blood serum, white of 

 2fg, or a very weak solution (1 part of salt in 200 



FIG. 143i. Microscopic Dissection. Teasing out with Needles. 



arts of water) of salt. For hardening tissues, sec- 

 ons, or organs, use the following reagents : Absolute 

 Icohol, methylated spirit, solutions of chromic acid 

 ;ome prefer a mixture of the latter and alcohol), 

 E bichromate of potash, picric acid, chloride of palla- 

 ium, and M tiller's fluid. All solutions of corrosive 

 g^ents should be used weak. Chromic acid, a quarter or 

 t most a 1 per cent, solution ; of bichromate of potash, 



or 2 per cent., picric acid, a saturated solution ; 

 bloride of palladium a one-tenth per cent., with a few 

 rops of hydrochloric acid added to prevent change, 

 liiller's fluid is made by adding together equal parts 

 f a 2 per cent, solution of bichromate of potash and 



1 per cent, solution of sulphate of soda. A short 

 mmersion in either of these solutions prepares tissues 

 Q 



