The Microscope. 133 



For showing living Infusoria, Rotifers, Chsetonoti, aquatic 

 worms and other animals at microscopical exhibitions, nothing could 

 be more satisfactory than Mr. Logan's slide. Using one at the last 

 soiree of the Trenton Natiu'al History Society the writer kept a 

 quantity of Turbellarian worms well and active until the small 

 hours of the morning. In this instance the slide was prepared so 

 hurriedly and so late that the cement was not dry before the hour of 

 the exhibition arrived, but an external application of the thin and 

 rapidly drying Brown's rubber-cement made all tight and appar- 

 ently not unpleasant for the worms. 



With these little contrivances of various sizes and depths, at all 

 times on my table, one or more is in constant use, and although not 

 particularly handsome, they are not unsatisfactory. If the reader 

 should find them useful I shall be glad, and the Editor will then not 

 regret the space he has placed at my disposal. 



STAINING AND MOUNTING PLANT SECTIONS. 



C. WELLINGTON. 



OTEMS of all kinds should, if possible, be cut when fi'esh. If 

 ^^ they cannot be obtained in this state, they may, previous to 

 catting, be soaked in cold or tepid water, or in a mixture of equal 

 volumes of alcohol, glycerine and water. Fresh stems or roots can 

 be preserved in this medium for almost any length of time, and will 

 remain in excellent condition for the section knife. Wood sections 

 require bleaching before being stained. The bleaching solution is 

 made by mixing one- quarter oz. of chloride of lime with a pint of 

 water, shaking occasionally for an hour, and after allowing the sedi- 

 ment to subside, decanting the clear solution. The process of bleach- 

 ing should be carefully watched and stopped when complete. 

 Tissues vary so much in color and density that no fixed time can be 

 given for bleaching them. Very thorough washing is necessary. 

 Mr. A. J. Doherty, in a paper to the Northern Microscopist, 

 describes at some length the method of staining in carmine and 

 green. The art consists of five stages, or processes : First, decolor- 

 izing the section ; second, washing the same ; third, preparing for 

 staining ; fourth, staining in carmine ; fifth, staining in green. After 

 bleaching and thoroughly washing to eliminate all the chemicals in 

 order to obtain deep colors, the section must be steeped in a mor- 

 dant composed of a ten per cent, solution of alum and water for 

 twenty-four hours, at the end of which time they will be ready to be 

 placed in the first staining fluid, the formula for which is as follows : 



