286 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



Plant Substances (pp. 262-387). The first two sections contain little 

 new or special information. The third deals with the preparation 

 of objects ; those not requiring to be cut, instruments for cutting, the 

 method of making sections (free-hand, in pith and cork, and in im- 

 bedding masses), the further treatment of the sections (removing air, 

 clearing, &c.), making preparations of fossil plants, mounting objects 

 (including living organisms), with the various preserving media and 

 varnishes, and directions for drawing. The fourth section gives de- 

 scriptions of and directions for preparing Microscopical Eeagents under 

 39 headings (19 inorganic and 20 organic), including iodine solutions, 

 staining matters, and the various carmine solutions. The fifth section 

 deals with the following substances : — Cellulose and its modifications, 

 Starch, Dextrin, Mucilage, Gums, Inulin, Grape-sugar (Glucose), Cane- 

 sugar (Saccharose), Albuminous Substances (Aleurone, Protoplasm), 

 Chlorophyll, Colouring Matters of Flowers, Asparagin, Inorganic 

 Constituents (Silica and Lime Salts), Glycoside, Tannin, Alkaloids, 

 Fats, Ethereal Oils, Camphor, Eesins, Phanerogamic Colouring Mat- 

 ters, and Cryptogamic Colouring Matters. The bibliography of each 

 substance is placed first, followed by a description of the substance ; 

 and, lastly, the methods most suitable for its demonstration. 



The book cannot fail to be useful to botanical microscopists, 

 though there is still room for a more extended treatise. 



* MierograpMc Dictionary.' — A fourth edition of this well- 

 known and useful guide to the microscopist is now completed, edited 

 by Dr. Grifiith, one of its original editors, with the assistance of the 

 Eev. M. J. Berkeley and Professor T. Rupert Jones. It bears marks 

 of revision to bring the contents down to date, the article on Angular 

 Aperture in particular embodying the results of the revival of the 

 discussion on aperture reported in the last volume but one of this 

 Journal. The editor gives a succinct explanation of the true view 

 of aperture, and appends to the very ingenious explanation of the 

 effect of oblique light given in the previous editions the statement — 

 " In this way we were wont to account for the action of large angles 

 of aperture and oblique light in rendering visible the finer markings 

 of objects," followed by a brief statement of the Abbe theory of 

 microscopical vision. 



In the Bibliography of the Aperture question appears an entry, 

 " "Wenham, Amer. Jn. Micros. 1881," which probably refers to some- 

 thing which was to have been. 



Behrens, "W. — Hilfsbuch zur Ausfiihrung mikroskopischer Untersuchungen im 

 Botanischen Laboratorium. (Guide to Microscopical Researches in the 

 Botanical Laboratory.) xii. aud 398 pp., 132 figs, and 2 pis. 



8vo, Braunschweig, 1883. 

 Berkeley, M. J. See GrifiSth, J. W. 

 Blackburn, W. — On Dr. Carpenter's Address. [Posf.] 



Micr. News, III. (1883) pp. 29-32. 



„ „ The President's Address to the Manchester Microscopical 



Society. 



[On some of the ways in which natural science has been promoted by the 



use of the Microscope, and the advantages derived from microscopical 



research in our social relations, as affecting our well-being.] 



3Iicr. News, III. (1883) pp. 93-105. 



