UNPEESSED MOUNTING FOR MICROSCOPE. lS3 



be decoloured by pouring Sodic Hypochlorite into the tube ; then, 

 after well washing with water, the rest of the process may be 

 followed as before, leaving out entirely the use of the soda-solution. 

 The great difference is in the matter of speed, as vegetable 

 preparations can be made far more rapidly than insect ones. It is 

 possible by this method to cut a dozen sections from a living 

 branch, — bleach, stain, and mount them in Canada Balsam or 

 Glycerine-solution, — and finally, ring and label them, all within 

 the hour. 



Should some of the preparations — our Blow-fly's head, for 

 instance — become too colourless and transparent, all we have to do 

 is to stain such by the addition of a few drops of an alcoholic 

 solution of some colouring matter (logwood answers well) to the 

 alcohol in the tube. The subsequent use of ether will fix the 

 colour. 



Usually after this treatment, the object will be found to be 

 quite clean ; but if not, it should be gently brushed with a camel- 

 hair pencil while in the turpentine or glycerine-fluid. The wings 

 of many insects are partially destroyed during the process, but 

 since these can, if desired, be easily mounted separately, this is 

 not of very great importance. 



The next point is how to mount our objects without ptessure. 

 Small insects, — such as Ichneumon-flies and Gnats, — parts of 

 insects, such as the legs, etc., — leaves and other portions of plants, 

 may be mounted in shallow cells, formed by running a ring of 

 gold-size or " Brown cement " on the glass slip. The brown 

 cement is very useful for this purpose, and is highly recommended 

 where a rapidly-drying and firm cement is required. For those 

 to whom expense is no object, the slips having cells hollowed 

 out in the centre should be chosen. 



Larger objects will need a deeper cell than any of these 

 afford ; and to form such, vulcanite rings are undoubtedly the 

 best, as also they are the cheapest. A number of these rings, of 

 various thicknesses, should be cemented to gTOWid-cdge glass slips. 

 Let no true microscopist indulge in the paltry saving effected by using 

 slips with rough edges. Though anyone possessed of such ultra- 

 frugality may have the right to cut his own fingers with their sharp 

 edges, he has no right to endanger the cuticle of his friends : and 

 if he intends to prevent this by covering up the slide with some of 

 the harlequin papers too often used, he will find that there is no 

 economy in the double purchase, either in the matter of time or 

 expense. 



Having prepared a number of vulcanite cells a day or so 

 beforehand, we select one just a trifle shallower than the object to 

 be mounted : and if the mounting is to be in any other solution 



