1883.] 



MICROSCOPICAL JOURNAL. 



157 



to osmotic action, but solutions of 

 osniic acid and of corrosive sublimate 

 in sea-water gave good results, A 

 few drops of a saturated solution of 

 iodine in alcohol, however, added to 

 sea-water, was found to give the best 

 results. The algte are first placed in 

 the iodine solution for thirty seconds 

 or a minute, and are then transferred 

 to 50 per cent alcohol. This method 

 of preservation may prove to be use- 

 ful for zoologists as well as botanists. 



Locomotion of Insects, — H, 

 Dewitz has confirmed the observa- 

 tions previously made by others that 

 insects are enabled to walk upon 

 vertical surfaces by virtue of a glu- 

 tinous exudation from the tips of cer- 

 tain hairs of the feet. By causing the 

 insects to walk feet uppermost on a 

 slip of glass under the microscope, 

 drops may be seen emitted by the 

 hairs which remain adherent to the 

 glass. In the bugs having no hairs 

 the fluid is exuded from the pores of 

 the feet. 



Paper Cells for Mounting, — 

 Mr, G, Busk has used paper cells for 

 mounting with great success. Some 

 porous kind of paper is chosen, of 

 suitable thickness, out of which rings 

 are cut, which are then thoroughly 

 soaked in benzol-balsam. When satur- 

 ated with balsam they are placed on 

 the slide when they become thoroughly 

 hardened and fixed. Such cells are 

 particularly adapted for watery media, 

 glycerine, oil or balsam, 



A good suggestion from the same 

 author is to use a lead-weight of 2-3 

 ounces, supported on three short pins 

 in mounting. Such a weight holds 

 the cover well pressed down, while 

 affording opportunity to clean the 

 edges of the cover-glass. 



A New Analyzing Prism, — The 

 new prism devised by Dr. Schroder 

 as an analyzer for the polariscope, 

 which will be introduced be Messrs, 

 Ross (Sc Co., possesses considerable 



advantage over the ordinary form. 

 We may be able to give a more full 

 description of it before long, but as a 

 preliminary notice it may be said that 

 it consists of a rhomb of Iceland spar 

 cut in such a way that the ordinary 

 and extraordinary rays diverge from 

 each other at such a wide angle that 

 one can be shut off by a stop on the 

 surface of the prism. 



The prism is mounted over the eye- 

 piece, and the upper plane of the 

 prism is in the plane of the image 

 formed above the eye-piece. As the 

 light from the ocular enters the prism 

 it suffers double refraction, so that 

 two images are formed, one beside the 

 other. Either of these images maybe 

 cut off by a stop, the other being used 

 for observation. Thus the prism acts 

 without diminishing the field of the 

 ocular. 



A New Ocular, — Dr, Schroder 

 has devised a new form of ocular, some 

 of which have been made by Messrs, 

 Ross & Co,, and subjected to trial. 

 We have not yet seen them, but ac- 

 cording to the testimony of a gentle- 

 man well qualified to judge, they are 

 far superior to any oculars heretofore 

 seen. At present we are unable to 

 indicate the novel features of their 

 construction. 



NOTES. 



— The second volume of Mr, Cole's 

 Studies in Microscopical Science will be 

 preceded by an introductory work, which 

 has been announced in the following 

 words taken from the Preliminary Pro- 

 spectus : — 



This work will be entitled " The 

 Methods of Microscopical Research^'' and 

 will contain chapters on " Instruments " 

 and their uses, " Reagents," their prop- 

 erties and special applications, and the 

 " Methods of Preparation " of typical 

 examples, in which an exhaustive descrip- 

 tion will be given of the processes of sec- 

 tion-cutting, hardening, staining, and in- 

 jecting, A chapter will also be devoted 

 to " Microscopical Art," in which full 



