328 



SCIENCE. 



[Vol. IX., No. 217 



three volumes, as they stand, form a compendium 

 of the greatest value, indispensable to all who are 

 engaged in any department of linguistic study. 



H. Hale. 



Professor Gage of Cornell university has re- 

 cently issued a pamphlet consisting of notes on 

 microscopical methods for the use of laboratory 

 students in the anatomical department of that in- 

 stitution. They are designed to accompany the 

 notes on histological methods which were pub- 

 lished last year, and to give only the main facts 

 and principles relating to the microscope and to 

 its manipulation, which seem indispensable for 

 the successful study of elementary histology. In 

 these notes the microscope and its parts are de- 

 scribed, and advice given as to its care, and also 

 the care of the eyes, which are apt to suffer unless 

 special precautions are taken to protect them. 

 Professor Gage advises that both eyes be kept 

 open, and the labor divided between the two eyes, 

 using one eye for observing the image awhile, and 

 then the other. He recommends the use of an 

 eye-screen made by pasting black velveteen on 

 bristol-board. The body of the microscope is re- 

 ceived in a hole cut in the middle of the length of 

 the screen and nearer to one side. The eye which 

 is not in use looks at the black surface, without 

 any strain or injurious effect. The micrometer 

 and its use are made clear, and a description given 

 of the camera lucida and the methods of drawing 

 the objects seen in the field of the microscope. 

 The differences between adjustable and non-adjust- 

 able objectives, and their advantages and disad- 

 vantages, are concisely treated, as are also im- 

 mersion objectives, and Zeiss' new apochromatic 

 objectives. This name has been given to his 

 objectives made of new kinds of glass. They are 

 made adjustable and non-adjustable, dry, and for 

 water and homogeneous immersion liquids. Alto- 

 gether, Professor Gage is to be congratulated on 

 having put a large anaount of valuable informa- 

 tion into a very small space, and that, too, without 

 having sacrificed clearness of description. The 

 figures, eleven in number, aid very materially in 

 elucidating the text. 



— Prof. John A. Ryder of the Biological de- 

 partment of the University of Pennsylvania has 

 recently had a new microtome constructed. It 

 cuts serial sections in ribbons, and is very com- 

 pact, occupying a space of only eight inches by 

 four. The sections produced are cut flat, and are 

 not parts of a hollow cylinder. The thickness to 

 be cut can be adjusted by a simple device, and 

 ranges from yj^q of an inch or .0025 mm. up to 

 ■^T^ of an inch or .0625 mm. The knife, an ordi- 



nary razor, admits of being placed at any angle, 

 as in a sledge microtome. The successive sec- 

 tions are cut as rapidly as the operator can move 

 his right hand up and down through a distance of 

 three inches. This new instrument was devised 

 in order to provide a simple, compact tool, adapted 

 to class-work, where many sections are required, 

 and for embryological, histological, pathological, 

 and botanical research, at far less cost than that 

 of the best sledge microtomes, and, though con- 

 structed very differently from the latter, is equally 

 accurate. Recently great improvements have been 

 added, so that it can be used as a rapidly cutting, 

 freezing microtome, or in cutting celloidin sec- 

 tions. With this new device, an object several 

 inches in length may be embedded entire, as a sin- 

 gle block, and cut up into a continuous series of 

 sections by the ribbon method. Cutting a large 

 block into a series of sections in this way is not 

 possible with any other microtome yet devised. The 

 range of capability of this new aid to research is 

 therefore very great, and will doubtless be appre- 

 ciated by teachers who wish to supply their pupils 

 with an abundance of illustrative material, with a 

 device fully three times as rapid in action as the 

 Thoma made by Yung, and with all its capabili- 

 ties for adjusting the knife and block. It is ad- 

 mitted by several competent histologists, who have 

 examined it, to be the most practical instrument 

 yet devised. 



— Prof. J. Vilanova y Piera, of the University 

 of Madrid, who has undertaken to edit a polyglot 

 dictionary of geological and geographical terms, 

 has invited Dr. John C. Branner, professor of ge- 

 ology in the University of Indiana, to take charge 

 of the Portuguese part of that work. Besides the 

 usual studies of the language. Dr. Branner has ac- 

 quired a practical acquaintance with the Portu- 

 guese during two visits to Portugal and a resi- 

 dence of nearly eight years in Brazil, where he 

 was assistant geologist upon the Imperial geologi- 

 cal survey. In the preface to the Spanish part of 

 the polyglot dictionary. Professor Vilanova y 

 Piera says that such a work was first suggested 

 to him by American geologists at a meeting of the 

 International congress of geologists. 



— The U.S. bydrographic office has published a 

 complete list of the charts, plans, and sailiag- 

 directions that had beerl published up to the end 

 of 1886. The catalogue will be a valuable book of 

 reference to students of American geography. 

 The supplements to the sailing-directions, which 

 were issued in December, 1886, contain a collec- 

 tion of all the additional information which has 

 from time to time appeared in U.S. ' Hydrographic 

 notices' and ' Notices to mariners.' 



