114 METHODS OF MICROSCOPICAL RESEARCH. 



melting point, and one part of that melting at 110, 

 will afford a mass which will answer perfectly well 

 when cut in a temperature of 70 D . That with the 

 lower melting point being combined in the propor- 

 tion of one-fifth of its bulk with four- fifths of that 

 of the higher melting point, will cut well in a tem- 

 perature of 60 ; whilst equal parts of the two 

 paraffins at 110 and 140 melting points respectively 

 will give the most satisfactory results when cut in 

 a temperature of 55 F. 



The paraffin is to be melted, in a water oven, in 

 porcelain pipkins (having covers and handles), and 

 the embedding may be done in paper or cardboard 

 trays, but it will be found more convenient and 

 much safer to use, according to the size of the 

 specimen to be embedded, the small porcelain pans 

 in which moist water colours are sold (these give 

 nice little firm blocks requiring no trimming) ; for 

 larger specimens, small porcelain vessels used in 

 various chemical processes are readily procurable, 

 whilst small glass vessels, or large (flat-bottomed) 

 test-tubes will answer admirably for specimens of 

 any considerable size. 



The specimens must be thoroughly hardened and 

 perfectly dehydrated, and when about to be embedded 

 are to be placed in strong alcohol, or, better still, in 

 absolute alcohol, for a short time ; from this they 

 are removed into creasote and left therein until they 

 are well impregnated (say for six hours). Having 

 removed as far as possible all creasote from their 

 surfaces, the specimens are placed in the melted 

 paraffin, in which, kept at a temperature slightly 

 above its melting-point, they are to remain from 

 one to four hours according to their size, and to 



