20 



MANUAL OF HISTOLOGY. 



the University of Edinburgh, Scotland, the specimen is placed in 

 a strong syrup (sugar, two ounces ; water, one ounce) for twenty- 

 four hours ; it is then removed to ordinary mucilage for forty- 

 eight hours, and finally is cut in the freezing microtome. 



These sections may be kept indefinitely in a preservative 



FIG. 10. 



FIG. 10. Poly-microtome (without freezing apparatus) : A, small well fitting on pyramidal bed-plate ; 

 B, pyramidal bed-plate containing different sizes; C, micrometer screw; D, ratchet-wheel attached to 

 screw ; E, lever actuating the micrometer screw by means of a pawl engaging in teeth of ratchet-wheel ; 

 F, arm carrying a dog, which prevents back motion of screw ; G, regulator for limiting the throw of 

 lever, and consequently governing the micrometer screw ; H, lever-nut for fixing regulator ; I, index, with 

 pointer and graduated scale, from 1/2400 inch to 1/200 inch ; K, knife for cutting sections ; L, knob to 

 turn micrometer screw direct when pawls are detached ; M, table clamp ; T, table of microtome, with 

 glass top to facilitate cutting. 



FIG. 11. (Very much reduced in size). A, B, tube containing specimen which is surrounded by freez- 

 ing mixture in tin receiver C, D ; B, F, revolving hopper with wings, W, W, for stirring the ice ; G, out- 

 let for melted ice. 



fluid recommended by Dr. Hamilton: 

 destil., aa. f iv. ; acid, carbolic., gtt. iij. 

 addition of alcohol, ij., is advisable. 



$. Glycerin., aquae 

 Boil and filter. The 



