HARDWICKE'S SCIENCE-GOSSIP. 



'11 



Bubbles in Glycerine Jelly. — With regard to 

 Mr. G. H. Bryan's remarks in this month's Science- 

 GossiP, I may say that I have used Deane's gelatine 

 medium for the past two years and always with the 

 best results ; in fact, slides made a year ago have 

 not shown any visible change, altiiough they have 

 made several journeys by rail during the time. In 

 mounting, I simply place the bottle containing the 

 medium in a cup of boiling water, and when liquid 

 drop on the object with a pipette, lower the covering- 

 glass carefully, and press out bubbles should they 

 be formed. When cold the superfluous jelly may be 

 scraped off with a penknife under cold water, and the 

 slide finished with a ring of varnish in the usual 

 manner. A short time ago, being unable to obtain 

 Deane's, I tried another maker, with the misfortune 

 of discovering all the objectionable qualities in his 

 preparation which have troubled Mr. Bryan. — J. D. 

 ButtereU. 



Mounting in Glycerine Jelly. — A question 

 similar to that of G. H. Bryan, page 208, was asked 

 by one of the members of the " Postal Microscopical 

 Society," in the note-book that accompanies the box 

 of slides of that society. I gave my experience in reply, 

 as follows: "The glycerine jelly (Dean's medium) 

 if overheated during the process of mounting, is very 

 apt indeed to shrink and cause vacuoles ; and this 

 shrinking occurs more readily if the object itself be 

 not quite dry. I have had many mounts thus spoilt, 

 but I do not give up the use of the medium, con- 

 sidering that due care is required not to overheat 

 when mounting. — Henry Bascz'i, Colonel. 



Parasite on Hydra fusca. — I think Mr. F. 

 George has been unfortunate in his selection of a 

 hunting place for Hydra fiisca, unless he was anxious 

 to find that zoophyte beset with parasites. If the 

 water of the Preston canal resembles that of other 

 canals it cannot be very clean, and the state of the 

 water would at once suggest an impaired state of 

 health of all its inhabitants. The higher forms of 

 life would by analogy suffer most. This would 

 absolutely support the theory of the editors of the 

 Micrographic Dictionary, viz., that the presence of 

 parasites is evidence of impaired or weak health. I 

 think the contaminated state of the water would cause 

 a less robust state of health than is enjoyed by the 

 irihabitants of pure water. It is the same in crowded 

 cities, not directly from the crowding but indirectly 

 from the contamination of the atmosphere. At all 

 events Hydra fusca is to be taken here, in ordinary 

 ponds or ditches, more or less entirely free from 

 parasites of any kind. I think also, in answer to the 

 second portion of Mr. F. George's query, that the 

 editors of the Micrographic Dictionary would in all 

 probability be inclined to consider that the absence of 

 the parasites in question would be a fair sign of 

 perfect health in Hydra fusca, in proportion as they 



believe their produce to be indicative of weak or 

 failing health.— C. //. Griffith, Stratficld Tin-giss, 

 Hants. 



Cleaning Slides. — A number of slides which had 

 been kept in cedar-wood drawers, were rendered use- ' 

 1 ess by a deposit from the wood of resinous matter 

 which thickly coated the exposed surfaces. The 

 edges of the glass covering the object were varnished 

 with asphalte. Failing to find a solvent which would 

 remove the deposit without injuring the asphalte 

 ring, I varnished the latter with a strong aqueous 

 solution of gum arable. After this had dried, the 

 slides were easily and perfectly cleaned by washing 

 with methylated spirits. The gum arabic was then 

 removed by washing with cold water. — J. W. Ogilvic. 



Mr. Tiios. Bolton's "Portfolio of Draw- 

 ings." — No. 6 of this interesting publication has just 

 appeared. As many of our readers are aware, it con- 

 sists of a half-yearly collection of the drawings and 

 notes which accompany Mr. Bolton's weekly bottles 

 containing living organisms. As the winter is draw- 

 ing near, our microscopical readers cannot do better 

 than enrol themselves among INIr. Bolton's subscribers, 

 and thus ensure a fund of intellectual amusement for 

 the long evenings, in the examination of the abundant 

 and interesting material which Mr. Bolton sends out. 



"Journal of the Quekett Microscopical 

 Club." — No. 47 of the above contains the following 

 papers : "On the Natural History and Histology of 

 Sponges," by B. W. Priest ; "On the Periodicity of 

 Filarial Migrations," by P. Manson ; "On a Zoo- 

 phyte Trough, Growing slide, or Live-box," by Rev. 

 II. J. Fase ; On " C/iona ciiiata—does the Sponge 

 make the burrow ?" by J. G. Waller. 



The British Bee-Keepers' Association at 

 South Kensington. — At the meeting on July 26th, 

 for the best microscopic slides illustrating the 

 natural history of the honey bee, Mr. F. Enock was 

 awarded the silver medal. The slides were four 

 dozen in number, and the preparation of parts in situ 

 without pressure gave an opportunity of examining 

 structure that flattened chitine could not afford. The 

 beauty of these objects is very great. On some slides 

 Mr. Enock brings side by side the homologous parts 

 of drone, worker and queen, which gives a ready 

 means of comparison, and on others displays the 

 parts illustrative of the complete anatomy of the 

 insect. Some sections and some specimens of the 

 interesting parasite Siylops Sfcncii were included in 

 the collection. 



Deutzia Scabia.— I think " Beginner " will find 

 Liquor Potassre the best to boil these in. It readily 

 mixes with balsam. I have tried it and found it 

 satisfactory.— y(^/^« Alex. OUard. 



