May, 1911. 



KNOWLEDGE. 



177 



fairlv equally on to all parts of the bones. The bones 

 are whitened more quickh' b\' adding a few drops 



Figure 1. A Skeleton of a Toad 'B;(/o rw/garis/. 



of caustic potash to the peroxide solution, but this 

 should onlv be done with the larger bones, as the 

 small ones absorb a good deal of the caustic and 

 rapidlv turn \ellow after mounting. In any case 

 very little potash must be used or else tubercles 

 and other markings will be obliterated. Hydrogen 

 peroxide is harmless, but caustic potash is not. The 

 bones should all be placed in the same strength of 

 bleaching solution and remain in it for the same 

 length of time, i.e., until all are whitened. But it is 

 advisable still, and indeed throughout, to keep the 

 hands and feet separate from the rest, each being 

 prepared in a separate dish. 



After bleaching, the bones should be washed care- 

 fully again in distilled %\ ater; anv debris still adherent 

 maj" be taken off w ith a soft brush and the bones 

 thoroughly dried. For this purpose a few racks are 

 required. For larger bones these are best made 



of what is known as expanded metal, i.e.. iron sheet 

 stamped through with slits and then drawn out into 

 diamond-shaped net-work. Squares of this material 

 are nailed on at the sides to wooden blocks, this 

 form of rack allowing the air to circulate freel\- all 

 round the bone. The iron should be covered with 

 -ome hard enamel to prevent the bones being 

 injured by rust. For small bones, a porous earthen- 

 ware plate such as is used by chemists for drying 

 crystals, is best, although blotting paper will 

 serve the purpose. The bones should be picked out 

 cine by one — not shot out promiscuously — and left to 

 dry for at least twenty-four hours. Should any 

 debris resembling bones remain in the solution, a 

 slight pinch with the forceps \v\\\ always indicate 

 their true character. 



There now oiih' remains the mountihs- This 



FiGUKt -.. 



A Skeleton of a Love Bird ( Androglussiiia agaponiis). 



