22 The Microscope. 



rareh' happens that this ornamental linishing touch is just the 

 thing that ruins the appearance of the slide. Nothing can be 

 neater than a^ well-mounted slide without those circles of gilding 

 or of red or 3'ellow paint that are sometimes seen on otherwise 

 commendable preparations. Such rings are unnecessary, and 

 unless used with great discrimination the}^ detract from the 

 pleasing aspect that a slide ma}' easily possess if the preparer 

 has a little good taste. It is rarel}^ in good taste to paint 

 colored rings on the cement, nor to use highh' colored cements. 

 Some microscopists contend that the object is as valuajjle in a 

 badly mounted slide, where it is nearer one end of the slip than 

 the other, where the Canada balsam or other resinous mounting 

 medium has been allowed to run over the glass and to dry there, 

 and where the whole aspect of the slide is disreputable and un- 

 wholesome. In such cases the object may be valuable and 

 important, but it would not be injured by a little attention paid 

 to the appearance of the slide itself. Microscopical work is neat 

 and clean, and the microscopist's slides should be no exception 

 to this rule. The beginner will do well if from the first he shall 

 try to mount well, and to finish his slides neatly. Gaud}' rings 

 and highly colored cements are to be deprecated, but neatness 

 is always a recommendation in every walk of life. I should, 

 therefore, recommend that a single cement be used to make the 

 cell and to finish the mount. 



The following are in common use. I shall tr}^ to point out 

 their good qualities and their bad ones, according to ni}' ex. 

 perience with them. There is an innumerable hoard in the market 

 and in the books, but with the following the microscopist will 

 be prepared to do almost any kind of mounting, and after be 

 has used some of these until he has become familiar with mount- 

 ing processes he may then experiment for himself, and perhaps 

 invent several others that shall be. better than anj^thing else in 

 the world of microscopical cements. Until that time arrives, 

 however, let me repeat that it seems best to select one or two 

 and to use them exclusivel}-, so as to become familiar with what 

 they will and will not do. 



BRUNSWICK BLACK. 



This is perhaps the oldest of all the recommended micro- 

 scopical cements. It is usuall}^ the first that the reader will 



