i88 



PRACTICAL HISTOLOGY. ' 



thus : Dissolve 56 grammes .potassium acetate in 28CC 

 hot water. When cold, add 2CC camphorated spirit, and 

 filter. 



352. Weak Spirit consisting of rectified spirit i part, 

 distilled water 3 parts was formerly much employed. 

 Muscle, connective tissue, and blood-vessels, can be well 

 preserved in it for a time, but sooner or later they become 

 granular and useless. 



352A. Rectified Spirit may be used for mounting soft- 

 ened bone and tooth. Glycerine renders these organs too 

 transparent if they are unstained. 



353. Naphtha and Creosote fluid is useful for pre- 

 serving urinary casts ( 222). 



354. CeUs for Microscopic Objects. Cells are made 

 of tissue paper, tinfoil, cardboard, dammar varnish, or white 

 zinc cement, or of glass. A paper cell is made by cutting 

 with a punch a paper circle the size of the cover-glass. A 

 hole is then cut in the centre with a punch of smaller size. 

 A cell of dammar or white zinc varnish (a, Fig. 62) is made 



FIG. 62. Cells. 



by tracing a ring of the substance on the slide with the aid 

 of Shadbolt's turn-table (Fig. 63), and then allowing it to 

 dry. A glass cell (b, Fig. 62) usually consists of a section 

 of a glass tube cemented to a slide with marine glue. Some- 

 times a sunk glass cell (c) is employed. It is merely a 

 depression ground in the glass. Delicate tissues that are 

 apt to be spoilt by the weight of the cover-glass should be 

 placed in a cell of tissue paper or gold-size. 



