232 



HARDWICKE'S SCIENCE-GOSSIP. 



circulation are of a varied nature, embracing all 

 branches of microscopy generally. There are also 

 special boxes devoted to histological and pathological 

 slides, and a few confined to such special branches of 

 microscopy as stellate hairs of plants, foraminifera 

 &c. I am just informed that the annual meeting of 

 the society will be held in London on September 30. 

 The honorary secretary will prepare and publish 

 a report of it, including the presidential address, the 

 list of members, rules, &c, early in October, and he 

 will be pleased to send a copy to any person desirous 

 of joining the society. Further particulars may also 

 be obtained of— C. P. Coombs., M.D., Castle Carey. 



On the mounting of Objects in Fluid for 

 THE MiCROSCOFE. — There are few ways of mounting 

 which have been so often attempted, and so often 

 given up as a failure as fluid mounting ; and yet 

 there are so many objects that are simply out of 

 the sphere of microscopical examination, unless 

 preserved in this way, and so many more which are 

 so immensely improved by it, that its difficulty and 

 attendant disappointments are much to be deplored. 

 I will not say that I have discovered a method 

 by which fluid mounting may be made perfect and 

 easy, for time proves the success of such things in 

 connection with that great enemy, leakage ; but so 

 far, I have been very successful with this class of 

 microscopic preparation, and am consequently anxious 

 to give the results of my experience, in the hope of 

 their being of some use to others, who, like myself, 

 wish to work upon objects which could not be 

 treated otherwise with the success derived from a 

 suitable fluid. The class of objects I have been 

 preparing is the ova of Crustacea ; but many other 

 specimens of marine zoology I have also treated in a 

 similar way. The fluid which I use is composed of 

 three parts absolute alcohol, two parts pure glycerine, 

 and one part distilled water, and it is important that 

 these components should be of the purest quality. 

 A number of ordinary tubes should be procured, and 

 the specimens can be kept in the above fluid (after 

 washing with distilled water) until it be convenient to 

 mount them ; the tubes should be carefully labelled 

 to avoid confusion, and as the preparing fluid is the 

 same as the mounting medium, it matters not how 

 long they are in preparation, in fact it is an improve- 

 ment to leave them some time, as some ova and zorea 

 throw down a precipitate which does not increase 

 the value of a slide. As regards the mounting itself, 

 the ordinary sunken cell will do for small or thin 

 objects, but I find for ova, &c, that these are too 

 shallow, so I use the glass ring cell which I fix to a 

 slip with marine glue, and as this must hz quite hard, 

 I prefer to have these cells fixed ready for use at least 

 a fortnight before using them, for in fluid mounting 

 haste means failure. We will now take one of these 

 deep cells, and run a ring of marine glue round the 

 top, say six hours before it is actually required, this 



will render the glue stiff enough to hold down the 

 cover glass without running in ; the cell should now 

 be breathed upon and the fluid (flesh fluid) poured in 

 until it is ready to run over. Now take up a small 

 portion of the ova and place it as required in the cell, 

 take a clean cover glass, the size of the cell, and 

 breathe on it, in order to moisten the surface, this 

 causes the fluid to run evenly without enclosing air 

 bubbles ; then place it gently on the cell one side 

 first, this presses out all the fluid not required, and 

 the marine glue, having no affinity for the fluid, cuts 

 through it, and unites the cover glass to the cell wall. 

 The slide should now be waved backwards and for- 

 wards in a large basin of clean water to cleanse it from 

 the superfluous fluid, and dried very carefully with a 

 hair pencil, and as soon as this is done, a small 

 quantity of zinc white cement should be dabbed very 

 gently on the junction of the cover glass and cell. 

 This zinc white is a capital cement for this work, as 

 it hardens rapidly and is very fine when dry. In a 

 few hours the slide may be put on the turntable, and 

 a good band of the above-mentioned white varnish 

 should be applied over the whole of the cell wall, 

 uniting the glass of the cover with the glass of the slip, 

 and if this coat be applied, say five times,* I do not 

 think that any fluid with ordinary usage will ever get 

 out ; when this has been done, any style of finish may 

 be applied as desired. I have said that time will 

 prove the strength of this method against air bubbles, 

 but I may mention that a slide of ova of one of the 

 mollusca which I mounted four years ago returned 

 to me safely after a long journey over England in one 

 of the boxes of the Postal Microscopical Society ; and 

 a slide that can stand such knocking about as postal 

 travelling must be fairly tough. I shall be very happy 

 either to give or to receive any further suggestions on 

 this subject, also to make any exchanges of ova and 

 zocea of named Crustacea for other fluid mounts of 

 these or other forms. — Edward Lovett, Holly Mount, 

 Croydon, 



ZOOLOGY. 



Ottawa Field Naturalists' Club. — We are 

 glad to receive from our transatlantic cousins a 

 copy of the first part of the Transactions published 

 by the above club. It evidences good work, for 

 besides the inaugural address, delivered by the 

 vice-president (Mr. James Fletcher) in the absence 

 of the president, it contains, amongst other matter, 

 papers on "The Graphite of the Ottawa Valley,'' by 

 Mr. W. H. Harrington ; " On the Forms and Struc- 

 tures of some Spongillre found in the Ottawa,'' by 

 Dr. A. F. Kemp ; " The Connection of Botany with 

 Mythology," by Mr. R. G. Ilaliburton ; " Cystidean 

 Life," by Dr. J. A. Grant; "Museum Education," 



* Allowing the previous coat to dry thoroughly first. 



