HARDWICKE'S SCIENCE-GOSSIP. 



6 7 



microscope must either not much exceed 4 inches, or 

 his objective has a power of only 4 diameters. If 

 this is not the case, he has made some error in using 

 his camera lucida, and instead of projecting the image 

 on the paper at a distance of 10 inches from the edge 

 of the camera, he has placed it at only 5 inches (or 

 less) ; this would of course diminish it one-half. 

 When desirous of ascertaining the magnifying power 

 of an objective and ocular, I place a six-inch scale 

 divided into jjths, the same distance from the eye as 

 the screw of the objective, and if one eye is directed 

 to the scale, and the other to the magnified image of 

 the divisions of the micrometer, the latter are seen 

 upon the former, and the amplification is easily 

 determined. As no microscopic illustration can be 

 of scientific value, unless its true amplification is 

 given, the correct magnifying power ef the objective 

 and ocular employed should be ascertained and 

 stated. — F. Kit ton. 



Meteorites. — Referring to H. M.'s remarks on 

 this subject (Science-Gossip, December 1882) — a 

 paper was read before the Quekett Microscopical 

 Club, in November last, calling attention to the fact 

 that the so-called Braunsfels Meteorite is not a 

 meteorite at all, but a quartzite. The opinion of 

 authorities was quoted, and specimens of ^quartzite, 

 &c, were exhibited, showing the similarity existing 

 between them and the so-called Braunfels Meteorite. 

 The above specimens of quartzite, &c, containing fluid 

 cavities, with bubbles which have spontaneous motion 

 (as often enclosed in quartz) were also exhibited side 

 by side, for comparison, at the last Conversazione of 

 the Royal Microscopical Society. — F.R.M.S. 



Studies in Microscopical Science.— We draw 

 especial attention to No. 38 of this admirable series — 

 a section of rock, "red syenite" from Ord Hill, 

 Sutherland, The slide accompanying the " study " 

 is a most important object, clearly showing all the 

 constituent parts, down to the air bubbles in the 

 quartz. The plate of the "study" describing the 

 syenite is coloured, and is one of the finest which have 

 yet appeared. The letterpress description is written 

 by Professor Heddle, M.D., and is very clear and full 

 of matter interesting to the student. 



Birds of Brazil.— The following books relate to 

 the ornithology of Brazil: Burmeister: " Systematische 

 UebersichtderThiereBrasiliens " (Leipzig, 1855-56). 

 Vols. 2, 3 relate to birds. Pelzen : " Zur Ornitholo- 

 gie Brasiliens " (Wien, 1871). Spix : "Avium Species 

 novae quas in itinereper Brasiliam anno 1817 collegit 

 et descripsit " (Monachi, 1824-5). Swainson, " Birds 

 of Brazil and Mexico " (London, 1841). Probably this 

 list may serve the purpose of G. A. K., who at p. 277 

 Vol. XVIII. asks for titles of works on Brazilian Birds. 

 — A Manchester Pythagorean. 



ZOOLOGY. 



Biological Works. — Mr. D. F. Howorth has 

 published an admirable paper (read before the 

 Ashton-under-Lyne Biological Society) on "The 

 Natural Sciences as illustrated in the Ashton-under- 

 Lyne Free Library." 



Local Ornithology. — We beg to call attention 

 to an admirably drawn up " List of the Birds of the 

 Banbury District," by F. C. Apton, B.C., the Rev. 

 B. D'O. Aplin, B.A., and O. V. Aplin. This List is 

 published under the auspices of the Banbury Natural 

 History Society, by John Potts, Banbury. 



Stafford Scientific Institute and Field 

 Club. — This society has made its influence felt in 

 Stafford by introducing popular science lectures. 

 The following gentlemen have addressed good 

 audiences on various subjects : Dr. J. E. Taylor, editor 

 of Science-Gossip, Mr. Richard A. Proctor, editor 

 of "Knowledge," and Professor W. Barrett, of 

 Dublin. 



Spiders. — The process described by Mr. E. 

 Lamplough (Science-Gossip, pp. 46, 47, February, 

 1883) is well known as that by means of which the 

 female spider is impregnated, and has frequently been 

 described by various authors, beginning with Martin 

 Lester in 1678. The exact .method of this process is 

 probably different with most spiders. What has not 

 been so frequently well observed as yet is the method 

 by which the spermatic fluid is transferred by the 

 male spider from its secreting organs to the palpal 

 organs. An exceedingly valuable paper on this (from 

 careful experiment and observations) was read a few 

 days ago before the Linnean Society by Mr. F. M. 

 Campbell, of Hoddesdon. I may add, for the benefit 

 of those who may wish to study our indigenous 

 spiders, that this subject is included, among others 

 connected with spiders, in a work by the present 

 writer, " Spiders of Dorset," published in 1879-81, 

 by the Dorset Natural History and Antiquarian 

 Field Club, pp. 1-625, withintroduction, pp. i.-xlii., 

 plates i.-vi. — O. P. Cambridge, Bloxworth, Dorset. 



Helix obvoluta. — I am glad to corroborate a 

 note which appeared in an old number of your valu- 

 able paper, as to Crabbe Wood, near here, being a 

 locality for that rare shell Helix obvoluta. I have 

 found it there for the last three years in company with 

 Clausilia rolphii, both alive, and also the empty shells 

 under hazels, where the snail always hibernates accord- 

 ing to my experience. Winchester is at least fifteen 

 miles from Buriton, the woods near which place are 

 the only locality I have been able to find in works on 

 conchology. Surely, therefore, its existence here is a 

 strong argument for its being indigenous, inasmuch 

 as (if my memory serves me rightly) Dr. Gwyn 

 Jeffreys reasons the same point from its occurrence 



