2y. 



HARDWICKE'S SCIENCE-GOSSIP. 



MICROSCOPY. 



Mounting Insect Organs, &c— W. B. asks 

 for information on above subject. The following is 

 the method I have adopted for some time, with satis- 

 factory results. Soak insect or organ in liquor 

 potassse for a day, or longer, if large. Wash and lay 

 out upon the glass slip, arrange in position, and 

 gently press while in the water with another slip. 

 Remove to weak solution of acetic acid for a few 

 hours, or longer, if not desired to finish rapidly. Wash 

 again in clean water, and transfer to glass slip and 

 drop on spirits of wine ; arrange the object and put 

 over another clean slip ; gently press and lightly 

 fasten with thread ; place end down in a small quan- 

 tity of spirits of wine and leave for a few hours, which 

 hardens in position. Then remove the thread and 

 gently lift off one slip, the whole still wet with the 

 spirit, when the object will adhere to one of the slips ; 

 drop on absolute alcohol and work object into centre 

 •of slide. Then apply oil of cloves, and in a few hours 

 the object will be ready for the balsam to finish. I 

 generally put such slides away for a month or two to 

 dry, but if put in a warm place they will be ready for 

 finishing with ringing cement in much less time. 

 For finishing I usually use shellac cement first, and 

 then finish with black or any other colour preferred. 

 — Charles D. Holmes, Hall, 



" Micro-Slides for Science Classes," by 

 B. Piffard. We have much pleasure in drawing 

 attention to a very interesting and instructive slide 



Fig. 139. — Section of stem of Water Lily {XympJiaa alba). 



just sent out, of the transverse section of the water 

 lily {Nymphaa alba). The accompanying illustration 

 will give some idea of the beauty of this object. 



Journal of the Royal Microscopical 

 Society. — The August part of this Journal contains a 

 very important paper (illustrated) "On the RedMould 

 of Barley," by Charles George Matthews, F.C.S. ; 

 other papers, also illustrated, are " On the Spicules 

 of Cucitmaria Hyndmanni, C. calcigera, and two 

 allied forms," by Professor F. Jeffrey Bell ; and " On 

 a Method of Preserving the Freshwater Medusa," 

 by Peter Squire, F.L.S. The latter is effected by a 

 solution of bichloride of mercury, which not only 

 preserves the animals, but also renders them perfectly 



opalescent, so that the minutest details of their 

 structure are visible. The strength of this solution 

 is four grains to one pint of distilled water. In 

 addition to above communication, there is the usual 

 well-digested "Summary" of papers, Sec, relating 

 to microscopical investigation and research. 



Catalogue of Works on Microscopy, &c. 

 We have much pleasure in drawing attention to Mr. 

 W. P. Collins's recently issued catalogue of Micro- 

 scopical and general scientific works. From it 

 students may derive much useful information, both as 

 to what books and papers have been published on the 

 various subjects of their special studies, and where 

 these can be obtained. Moreover, Mr. Collins's 

 catalogue is a model of neat arrangement. 



Another Revolving Table. — On pages 208 

 and 209 of Science-Gossip for this month, C. A. 

 Lowe gives details of construction of an ingenious 

 "substitute for a revolving-table " for use with the 

 microscope. I have somewhere seen a much simpler 

 contrivance recommended, which I believe would 

 answer the purpose equally well, and cost less (both 

 in cash and time) to make. A piece of board of any 

 shape preferred, large enough to hold the microscope 

 with lamp and stand-condenser, and about \\ inch 

 thick, is covered on one side with American leather- 

 cloth, and on the other with green baize. The cover- 

 ing material in each case to be turned over and nailed 

 on the edge of the board, and the junction of the two 

 edges of material covered with a strip of leather or 

 braid, running all round the edge of the board. 

 If the table has a polished top, or is covered with 

 ordinary table-baize or " oil-cloth," the green baize 

 side of the board should be downwards, but if a cloth 

 table-cover is in use the American leather side should 

 be downwards. A board of this kind with microscope 

 and lamp can be slid easily across or around a table 

 in any direction, and of course will answer equally 

 well for a square or oblong table as for a circular one, 

 which is not the case with any contrivance working 

 on a radial arm. — IV. Officer. 



A Substitute for a Revolving Table. — Pos- 

 sibly the following may be of some use to your 

 numerous readers, who look for help from the pages 

 of Science-Gossip. I have a table with a metal 

 stand and a fixed mahogany top, over which I placed 

 a cover of stout oil-cloth, which envelopes about three 

 inches ; it is then drawn underneath the table by 

 means of strings, in the same manner that the mouth 

 of a bag is closed, of course not drawing too tight ; 

 the oil-cloth cover will then revolve with the greatest 

 ease, even when it has a considerable weight upon it. 

 I have used this table with great success and comfort 

 for more than ten years, and have put it to the 

 severe test of a Conversazione. Any small table with 

 a round top may be used, and if it should be a light 

 one, to give it greater fixity, heavy books may be 



