1893.] MICROSCOPICAL JOURNAL. 309 



pheric excluder ; and now yon will see why difficult subjects 

 such as cobras and bloodsuckers, previously prejiared, broke 

 down. The tissues had absorbed from the alcohol or arsenic 

 paste, or reduced gum and glycerine, a large proportion of water 

 in addition to that nnturally contained in them, and conse- 

 quently more than the carbolic acid could extract or combine 

 with, the result being that they had an atmosphere, so to speak, 

 of their own, which finally led to their more or less speedy de. 

 cay. 



Here is then a splendid medium for the zoologist, especially 

 in a hot climate. He is furnished with a powerful and easily 

 used preservative both for form and color which does not evapor- 

 ate. The leg of a fly laid on a glass slide in a drop of oil, and 

 just simply covered by an ordinary microscopic glass cover, 

 has remained in the same state for eighteen months. I need 

 not say what a boon this will be to the microscopist, who, whilst 

 wishing to study some subject, does not wish to mount his 

 S])ecimens permanentl3^ 



I noticed how exceedingly hard some spiders had become in 

 the oil, when it occurred to me that specimens that had become 

 so firm would resist the dehydrating action of glycerine ; and 

 that if spiders would, anything would. The experiment was at 

 once tried on a large rattle snake, seven feet long, some frogs 

 and fish, colored and uncolored with great success. 



The oil is also an admirable preservative for large fish skins 

 that can be mounted afterwards. They require no varnishing 

 and retain much of their lustre. 



Cocoanut oil is solid at 68° F. In the coldest months in Cey- 

 lon it is solid in the early hours of the morning, even on the 

 sea coast, and in the hills it is always solid, as in Europe. When 

 collecting, a gallon or two is melted every morning, which will 

 keep fluid for half a day. The animals are placed in this. When 

 the oil solidifies it forms an excellent packing. W^hen they 

 arrive at the Museum they are are allowed to soak in the fluid 

 oil for some weeks. In Europe the oil will have to be kept fluid 

 in a warm room or oven, or some substitute found for it. , 



The Recipe. — Add carbolic acid to cocoanut oil till the oil 

 marks 10 to 20 degrees below proof on an hydrometer. The 

 more acid the more powerful the dehydrating effect, and judge- 



