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HARD WICKE 'S S CI EN CE-GO SSI P. 



scopical Society held their annual meeting in their new 

 rooms, 6, Pall-Mall-piace, W., in January, under the 

 presidency of Dr. Payne. The secretary's report 

 showed that twelve papers on important subjects had 

 been read during the year, of which four were 

 illustrative of new forms of instraments applied to 

 medical histology. The number of members of this 

 society in December last was 129. Dr. Payne de- 

 livered an address on the above occasion, chiefly on 

 the study of histology, and in the course of his 

 remarks he reviewed the scope and bearing of most 

 of the important papers which had been read. 



The Fresh-water Sponge. — At a recent meet- 

 ing of the East Kent Natural History Society, Mr. 

 Fullagar (who has been successful in getting it to live 

 and grow in confinement) again exhibited the fresh- 

 water sponge [Spongia fluviatilis), illustrated by 

 diagrams, showing (since the last meeting, December 

 6th) the production by growth of the pellucid, semi- 

 Iransparent, gelatinoid substance termed sarcode, 

 which had extended to some distance on the glass cell 

 in which it was placed ; in the new sarcode the pores 

 through which the current of water enters the sponge 

 were obsei-vable, fonning the in-current, bearing with 

 it the nutriment on which the sponge feeds. In the 

 newly-formed sarcode was to be seen a number of 

 new spicules ; they were pointed at each end, and 

 their middle or centre was bulged out, from which the 

 growth extended to both terminal points ; the mature 

 spicules are a little bent or curved, and pointed at both 

 ends, but not bulged out in the middle. Some good 

 specimens of the mature spicules have been cleaned 

 and mounted by Mr. Hammond. They are com- 

 posed of the pure silex, as transparent as glass. The 

 peculiar spicules of the ovaria were beautifully shown 

 under the microscope. In a specimen Mr. Fullagar 

 had successfully mounted in damar, by first drying the 

 ovaria and then in a drop of damar with a thin glass 

 cover gently pressed down, the granular contents of 

 the ovaria were pressed out, and the beautiful stellated 

 fonn of the spicule was seen standing out in form of 

 so many miniature palm-trees : the real form of them 

 is stellated at the two ends, connected together by a 

 shaft, similar to two wheels on an axle. This form 

 of spicule in the ovaria performs the double office of 

 tension and defence. 



On Cleaning Microscopic Slides. — For re- 

 moving Canada balsam from spoilt or useless slides, 

 turpentine is, I believe, in general use. If the slides 

 be immersed for about two minutes in strong sul- 

 phuric acid, heated to about 100" Fahr., the balsam 

 will be decomposed into a filmy substance, easily got 

 rid of by washing with cold water. If the acid is 

 cold, the time will be somewhat longer. Circles of 

 asphalt and rubber, the deposit of carbon from a 

 lamp, which is sometimes very difficult to remove by 

 other means, turpentine from beakers, bottles, &c., 

 may be done in the same manner. — ]V. M. Patcrson. 



Mounting in Damar. — As the writer of the 

 article on damar, which has given rise to several 

 remarks and suggestions as to using that fluid aright 

 (see " Damar as a Mounting Medium," S. G. 1876, 

 p. 254), I should like just to mention that Mr. 

 E. B. L. Brayley has very kindly sent me two or 

 three specimens of slides mounted in the manner 

 described by him in the April number. I have 

 thoroughly examined and tested these slides, and must 

 say that, as far as I can judge, they are of a very supe- 

 rior character ; for not only are the slides free from 

 air, but the damar is thoroughly hard. I have not 

 had time to try Mr. Brayley's method myself yet, as 

 requested by that gentleman, but I feel sure that when 

 I do so my opinion will be the same as above. Cor- 

 respondents complain of there being no varnishes 

 sufficiently tough to use with this medium ; but is this 

 not more the fault of the mounting and moistness of 

 the damar than of the varnish ? If this is not the 

 case, how is it that, though I have never used any but 

 asphalt varnish, I find all my slides perfectly dry and 

 clean, without the slightest appearance of varnish 

 having run in ? To say that I have never had such a 

 mishap happen to my slides would be simply stating 

 what is untrue ; but then, when the varnish has run in, 

 it has either been from the fact that the damar was 

 not sufficiently dry, or the varnish too liquid. As for 

 air-bubbles, I never find any trouble with them ; and 

 I think that, did others but follow my plan (see my 

 paper, p. 254, 1876), they also would have less reason 

 to complain. Doubtless the thorough hardening of 

 the damar, as achieved by Mr. Brayley, will do more 

 for making damar a popular mounting medium than 

 anything one could write or say in connection with 

 its other valuable qualities. — Charles F. W. T. 



IVilliants, Redland. 



ZOOLOGY. 



Provincial Societies. — We have received the 

 reports of meetings of various provincial natural 

 history societies, all of which indicate the spread of 

 the spirit of scientific inquiry. The "Botany of 

 Northamptonshire " has been the subject of an able 

 and exhaustive paper by a well-known correspondent 

 to our columns, Mr. G. C. Druce. The report of 

 the Chichester and West Sussex Natural History 

 and Microscopical Society has just been issued for 

 1876-7, and shows that thirteen papers have been 

 read during the year on various geological, botanical, 

 and zoological subjects ; in addition to two very suc- 

 cessful summer excursions, and one annual exhibition 

 held during two days in September. The East Kent 

 Natural History is strong in well-known names, and 

 we think it is a pity its Transactions are not published 

 in a fuller manner. Mr. James Fullagar has been 

 exhibiting and making additional discoveries in the 



