ON PREPARING SKELETONS. xxxv 



slide must be placed in 30 per cent, alcohol, then in water, and 

 then into stain. After being in stain the requisite amount 

 of time, the excess of stain is removed by washing in some 

 suitable reagent, and the slide is then passed gradually through 

 50 per cent., 70 per cent., 90 per cent, to absolute alcohol, 

 where it is allowed to remain a few minutes in order to 

 thoroughly dehydrate. After dehydration oil of cedar- wood 

 is poured over the sections till the alcohol is all removed and 

 the oil flows freely over the slide. The excess of oil is then 

 removed, balsam placed on the sections, and they are covered 

 in the usual way. 



Curled or crumpled sections should be straightened before 

 mounting, so that all the parts of the object He in one plane. 

 This can be done as follows : Smear the slide with glycerin 

 and albumen, and place a few drops of clean (or distilled) 

 water on the slide. Place the crumpled sections on the water 

 and very gradually warm the slide. As the water becomes 

 warm the creases will disappear, and the sections will lie 

 perfectly flat on the water. Great care must be taken not to 

 melt the paraffin, as this causes great contraction and spoils 

 the sections completely. When the sections are quite flat, 

 the water may be drained off, or removed by the application 

 of blotting-paper. The slide is then placed for a few hours in 

 an oven or incubator whose temperature is lower than the 

 melting-point of the paraffin used. When quite dry the slide 

 is warmed to melt the paraffin, placed in xylol, and treated in 

 the usual way. 



XII. ON PREPARING SKELETONS. 



Skeletons of rabbits, fowls, &c, may be prepared by mace- 

 ration or by boiling. Before macerating the bones should 

 have most of the flesh cut off ; they are then to be put into 

 cold water and left for several weeks for the remaining flesh 

 to rot away. They will afterwards require copious washing, 

 and may then be bleached by exposure to direct sunlight for 

 two or three weeks, during which time they should be re- 

 peatedly dipped into water and then left to dry. This same 



