338 The Microscope. 



glycerin merely to make sure of a diagnosis, is found to contain 

 some rare or beautiful features. But there it is in glycerin, care- 

 lessly mounted and quite prepared to be thrown away, and, unless it 

 happens to be a very rare object, it is thrown away. 



Dr. R. H. Ward, of Troy, N. Y., has an article on this point in the 

 last number of The Journal of Microscopy and Natural Science, 

 and recommends Farrant's medium as a quick and convenient first 

 and final mounting material. In corroboration of what we have 

 said, he writes: "Objects almost without number are examined for 

 purely scientific investigation, or for sanitary, economic, medical or 

 legal purposes, and then are inevitably thrown away for want of the 

 time required, bat not just then available, for mounting them. Such 

 objects are often examined in glycerin, and proving interesting, 

 they are laid aside unsealed, only to be found spoiled when next 

 seen, or are ringed with varnish, without a cell, to make a mount 

 that will be short-lived by reason of the running in or splitting off of 

 the cement. It is no more trouble to place such objects, and cover 

 them, in the gum and glycerin medium at first, than in plain gly- 

 cerin; and then they are already mounted to begin with, and they 

 can, as desired, be washed off the next day, or be neglected for years 

 without injury." As the Farrant's medium the doctor recommends 

 is somewhat different than the one used by us, and because he speaks 

 of it as permanent, we give it here: 



Picked gum arable 4 parts by weight. 



Distilled water (cold) 4 • " " 



Glycerin 2 " 



Keep in a glass-stoppered bottle, in which should be put a small 

 piece of camphor. The directions given by the doctor do not differ 

 materially from those found in the books on the use of the medium. 



We advise some of our busy readers to tiy it and watch the 

 growth of a collection which has cost them no extra work more than 

 has been given to the specimens heretofore thrown away. 



Acknowledgements. — From C. Wellington, Jackson, Mich., 

 mounts of vegetable tissues; from J. Krutschnitt, New Orleans, La., 

 mount of epidendrum ovary; from L. A. Harding, mount of chro- 

 mate of stry china; from W. Orin Tasker, Haverhill, Mass., photomicro- 

 graph of one of Rimbock's slides of arranged diatoms, 273 objects. 



Professor W. K. Brooks contributes to the September and Octo- 

 ber Popular Science monthly some papers on sponges that will be 

 of interest to microscopists. 



