HARDWICKE'S SCIENCE-GOSSIP. 



■/D 



inches ; from the globe to the mirror about eiglit to 

 twelve inches. As the height of the globe cannot be 

 altered the necessary adjustments must be made with 



(C C| 

 the lamp, e.g. if the mirror is at <B B> A, the lamp 



(A A) 

 llame must be at C ; if at C, the flame must be at A. 

 I have just received a letter from a friend to whom 

 I recommended the illumination, in which he writes, 

 " I am delighted with the black ground illumination, 

 which is certainly softer, and the definition sharper 

 than any I have tried before. Have you tried it with 

 polarised light ? I think you would be pleased with 

 it, there is such great softness of tint and such im- 

 penetrable blackness of field when the prisms are 

 crossed." — F. Kitten. 



Staining Vegetakle Tissues not a Modern 

 Invention. — Probably the earliest method of stain- 

 ing vegetable tissue is that described by John Hill, in 

 his work on "The Construction of Timber from its 

 early growth, explained by the microscope and 

 proved from experiments in a great variety of kinds. 

 By John Hill, 1774." The following is a condensed 

 description of his modus operandi. Dissolve one 

 drachm of sugar of lead in one ounce and a half of 

 water ; filter the material. A stem, or piece of a 

 small branch of a tree is to be immersed upright for 

 half its length in this solution, and covered with a 

 glass to prevent evaporation, and allowed to remain 

 two days in it. Cut off the part immersed and throw 

 away. Place the remaining piece in orpiment 

 lixivium (which is thus prepared). Place in a basin 

 two ounces of quicklime and an ounce of orpiment 

 (yellow sulphate of arsenic) ; pour upon them one pint 

 and a half of boiling water. When it has stood a 

 day and a half, it is fit for use. By this process a 

 deep brown stain is produced. — F. K. 



Foraminikera in Chalk. — Mr. Hicken will 

 have no difficulty in obtaining abundance of these 

 organisms if he places a small piece of whiting in a 

 test-tube and pour some boiling water upon it. When 

 cold let it be well shaken, and pour off all that does 

 Jiot subside in one minute. Repeat the process 

 until the water is clear. After the expiration of 

 that time, mount in balsam. Hard chalk or clay 

 sometimes requires the aid of a stiff tooth-brush 

 to break it up. Limestone must be ground thin 

 and mounted in balsam. Hydrochloric acid will 

 dissolve the calcareous matter, leaving any siliceous 

 forms uninjured. — F. K. 



Habirshaw's Catalogue of Diatomace^. — 

 I have just received Part I. of this work, edited and 

 published by Mr. Romyn Hitchcock, of 53 Maiden 

 Lane, New York, and to be completed in four parts. 

 The price is 5^. bd. a part, and only 250 copies are to 

 be printed. To any one who has no acquaintance 

 with the Diatomacese, the book will appear to be 

 little more than an alphabetical string of unintelligible 



references ; but to those who have studied them, or 

 who desire to do so, it is invaluable. Only those who 

 have attempted the compilation of such a catalogue 

 can realise the labour involved in its production ; and 

 it is to be hoped the remaining three parts will 

 speedily follow. There are, of course, slight errors ; 

 for instance, at p. 17, 1. 24, after " j\I. J." should be 

 inserted " i860," and again, at p. 25, 1, 13, "J. M." 

 should be " T. ]\L S." — not to mention others. A 

 few such errors are, however, inevitable, but the 

 immense utility of the work far outweighs them. 

 Though one may possess the numerous necessary 

 books of reference and may have an intimate acquaint- 

 ance with the DiatomaceK, none but those who have 

 tried can realise the time occupied and the uncer- 

 tainty involved in trying to find the description or 

 figure of any particular species. The want of such a 

 catalogue has long been felt, and the thanks of 

 Diatomists are due to Mr. Habirshaw and his pub- 

 lisher for now supplying the want. — H. Ranisdcii. 



South London Microscopical and Natural 

 History Club. — The above society have just re- 

 moved to new quarters in Brixton Hall. It is an 

 important move, inasmuch as it is approved by nearly 

 every individual in the club. The rooms of the 

 general meetings are now more in unison with the 

 standing of the society, being brighter and larger in 

 respect to the library room. At the last general 

 meeting a very interesting paper was read by Sibert 

 Saunders, Esq., of Whitstable, upon "Barnacles." 



ZOOLOGY. 



Science in the Provinces. — The report of the 

 Proceedings of the Seventh Annual Meeting of the 

 Norwich Science Gossip Club, contains the address 

 of the President (Mr. James Carver), in which he 

 gives a brief resume of the past session. The subjects 

 reviewed are the following : Astronomy, Heraldry, 

 General Literature, Botany, Geology, Entomology, 

 Physical Science, Social Science, Travel, &c. We 

 oommend the structure and management of this 

 spirited club to the attention of those towns where a 

 similar society may be in process of formation. 



Science Teaching. — We see that Mr. W. J. 

 Harrison, F.G.S., has read a valuable paper on 

 "The Teaching of Science in Public Elementary 

 Schools," before the Birmingham Philosophical 

 Society. The Appendix, containing a scheme of 

 instruction in Elementary Science, as carried out in 

 the Birmingham Board Schools, will be found useful 

 to all engaged in the work of education. 



An Unusual form of Amceba. — With respect 

 to the rhizopod described and figured by Mr. J. 

 Fullagar of Canterbuiy, in the October number of 

 Science-Gossip, p. 226 — a form closely resembling; 



