AND SANDARAC IN MICROSCOPY. 17 



balsam, because amylic alcohol shows the property of spreading 

 rapidly over a surface and would creep over the edge of the cover- 

 glass on to the slide ; this difficulty is avoided by the use of 

 a cork. 



Pseudo-scorpions and mites may be very simply prepared 

 ior mounting by taking material, either fresh or preserved in 

 alcohol, and macerating in chloral- phenol until quite trans- 

 parent. (Chloral- phenol is the liquid obtained by mixing 

 together equal weights of phenol crystals and chloral hydrate 

 3.nd warming gently until liquefied.) The specimens are then 

 lemoved on the tip of a fine sable-hair brush to amyl- phenol, 

 and finally to a microscope slide and covered by amyl-sandarac 

 and a cover- glass. Although it is not always desirable, this 

 method enables one to avoid preliminary treatment with potash 

 or soda, when one wishes to do so. In any case, the resulting 

 preparations are really permanent in character and therefore 

 preferable to those made by the use of glycerine jelly, and the 

 low refractive index of the amyl-sandarac makes clearly visible 

 the hairs and the outlines of the chitinous plates, features which 

 are almost obliterated by the use of benzol-balsam. 



By a similar treatment one can make good permanent mounts 

 of liverworts and mosses, which are first thoroughly relaxed by 

 immersion in boiling water, excess of moisture being removed 

 by blotting-paper. In this case it is often desirable, after 

 soaking in chloral- phenol, to boil the liquid gently so as to 

 expel the air thoroughly. Transfer to amyl- phenol and mount 

 in amyl-sandarac. The preliminary treatment with chloral- 

 phenol is not always necessary, since amyl-phenol alone will 

 render the plants quite transparent and dehydrated, if they are 

 soaked in it for a sufficiently long period. 



These instructions for mounting should not be followed too 

 xigidly. It will be found in some cases that steps may be safely 

 and advantageously omitted, while in other circumstances 

 additional precautions must be taken. 



For example, it is generally necessary to subject insects, 

 spiders, etc., to a preliminary treatment with caustic alkali ; 

 but in the case of a small beetle which had died and become 

 ■quite dry, I found that an excellent mount was obtained with- 



JoURN. Q. M. 0., Series II.— No. 84 2 



