272 



SCIENCE. 



BOOKS RECEIVED. 



Methods and Results. — Description of an im- 

 proved Vertical Clamp for the Telescopes of the The- 

 odolites and Meridian Instruments — United States 

 Coast and Geodetic Survey — Appendix No. 13 — 

 Report for 1877 — Washington Government Printing 

 Office, 1880: 

 The advantages of this improvement, which has been 

 devised by Mr. George Davidson, an assistant of the 

 United States Coast Survey, may be briefly stated as fol- 

 lows : 



I. The telescope is clamped with sufficient firmness 

 to admit ot its being moved in altitude in the vertical 

 plane by the slow-moticn screw. 



II. The clamp maybe made to hold the transit-axis so 

 gently that a very delicate tap on the telescope will bring 

 the latter to the desired elevation. 



III. The top of the clamp is open, so that it permits 

 the telescope to be lifted out for reversal and readily- 

 replaced in the Y's without carrying the clamp with 

 it. 



IV. The jaws of the open clamp remain during reversal 

 in the same position as when undamped before the re- 

 versal of the telescope. 



V. There is no tendency to lift the vertical plate 

 through eccentricity of the slow-motion screw, and con- 

 sequently no resultant movement of the transit axis in 

 azimuth. 



We advise those who would like to know more of 

 this improved clamp to address directly to Mr. Davidson, 

 whose address is United States Coast and Geodetic 

 Survey, San Francisco, Cal. 



Manual of the Vertebrates of the Northern 

 United States. By David Starr Jordan, 

 Ph. D., M. D., Professor ot Natural History in In- 

 diana University, 3d Edition. Revised and Enlarged. 

 Jansen, McClurg & Company, Chicago, 1880. 



This book, which was originally written to afford col- 

 lectors and students who were not specialists, a ready 

 guide for identifying the families, genera and species 

 of our vertebrate animals, is now again presented to the 

 public in a third edition, which would appear to indicate 

 that the work meets a demand made by Naturalists, and 

 has been received with approval. 



This is a purely technical work, the author confining 

 himself strictly to details necessary to be understood 

 for scientific classifications, while signs and abbreviations 

 are freely used to reduce the matter to its lowest limits. 



The author has been assisted by such eminent natural- 

 ists as Dr. Elliott Coues, Professor E. D. Cope, Dr. 

 Theodore Gill, Professor H. E. Copeland, Mr. E. W. 

 Nelson, Mr. B. II. Van Vleck, Mr. C. H. Gilbert and 

 Dr. A. W. Brayton, and efforts have been made to in- 

 clude in this edition the results of recent investigations 

 in this department of scientific research. 



The ground covered by this work includes the district 

 east of the Mississippi river, and north of Carolina and 

 Tennessee, exclusive of marine species. 



The work concludes with a good glossary of the prin- 

 cipal technical terms used in the book, a glossary of spe- 

 cific names, and also an indrx to names of genera and 

 higher groups with their derivations. 



This manual of the vertebrates will prove valuable, not 

 only to students, but to the large class of amateurs who 

 desire to classily the forms included in this work. 



Tiik Electric Laryngoscope, by A.Wellington 



Adams. jM. I). [Reprint from the Archives of La- 

 ryngology, Sept. 1880.] 

 We are once more reminde I, by this little pamphlet, of the 

 manifold applications of the electric light in the practical 

 departments of medicine and surgery. Dr. Adams claims 



for the instrument he has devised, the following advan- 

 tages : 1. The application of what is the nearest approach 

 to sunlight — the electric light — in such away as to bring 

 it under perfect subjection and be readily manipulated. 

 2. The establishment of a permanent relationship between 

 the source of light and the throat mirror. 3. The use of 

 a light which emits neither gas nor heat, and is of such 

 concentration and intensity as to illuminate the respira- 

 tory tract down to a point nearly an inch below the " bi- 

 furcation," so that every detail in the larynx and trachea 

 down to that point is sharply defined in the throat 

 mirror, and if the latter be large and slightly concaved, 

 any particular detail requiring special structural examin- 

 ation may thus be greatly magnified. 



The Vacations of the Fixed Points of Mercurial 

 Thermometers, and the Means of Recognizing them in 

 the Determination of Temperatures. — J. Pernet agrees 

 with M. Crafts that the part played by pressure in the per- 

 manent elevation of the zero-point is very trifling, if it exist 

 at all. 



Boro-deci-tungstic Acid and its Sodium Salts. — Ac- 

 cording to D. Klein, if tungstic acid in excess is dissolved 

 in a boiling solution of borax with twice its molecular weight 

 of boric acid (crystalline), the ebullition kept up for some 

 hours, the undissolved tungstic hydrate filtered off the re- 

 sulting solution deposits crystals of boric acid and sodium 

 polyborates. The mother-liquor, if concentrated and 

 placed in a vacuum, deposits first borax and then the ex- 

 ceedingly soluble sodium salt of the new acid, containing 

 2 mols. of constitutional water. 



Appearance of Ozone on the Evaporation of Vari- 

 ous Liquids as a Lecture Experiment. — R. Bottger recom- 

 mends to moisten a piece of paper uniformly with starch 

 containing cadmium iodide, to let fall upon it a few drops 

 of alcohol or ether, and to set the latter liquid on fire. 

 After its evaporation the paper is found turned decidedly 

 blue in consequence of the formation of ozone. — Pol. Notiz- 

 blatt, 35, 95. 



Singular Behavior of Stannous Chloride with Po- 

 tassium Chlorate. — R. Bottger states that if 2 parts of stan- 

 nous chloride and 1 part potassium chlorate, both previously 

 pulverized, are rubbed together in a porcelain mortar, the 

 mixture becomes very hot, chlorous acid and watery vapor 

 are evolved, and there remains a yellowish white mass, 

 which, if dissolved in boiling water, deposits potassium 

 perchlorate in micaceous crystals. The. mother-liquor con- 

 tains tin oxychloride. 



Hypochlorine and the Conditions of its Origin in 

 Plants. — M. Pringsheim has demonstrated the existence 

 of a body in the green cells of plants, which he named hy- 

 pochlorine on account of its relation to chlorophyll. He 

 has quite recently described, in a paper, its occurrence and 

 iis microchemical characters. 



CHLORIDES <>r- Camphor. — The products which arise on 

 the action of phosphorus pentachloride upon camphor are 

 affected by the quantity of the phosphorus chloride present 

 and by the temperature. If every increase of temperature 

 is prevented no hydrochloric acid appeals, and there is 

 formed a homogeneous camphor dichloride in theoretical 

 quantities. Pfaundler's dichloride, and the body melting 

 at 6o° and desi ribed as monochloride, are probably merely 

 mixtures. F. V. Spitzer — Wien. Anzeiger, 18S0, 71. 



Decomposition of Simple Organic Compounds by Zinc- 

 dust. — The highei alcohols from ethylic alcohol upwards, 

 on distillation ovei zinc-powder which was heated to 330 , 

 to 350, were decomposed into the corresponding define 

 and hydrogen, Undei the same circumstances methylic 

 alcohol is resolued into carbonic oxide and hydrogen. 

 Hans Jahn. — Wiener Ameiger, 1880, 73-74. 



New Synthesis 01 Dimei hyl-acrylic Acid. — This com- 

 pound is formed along with ethylisoxy-valerianic acid when 



In om-iso-v.il' 1 1.1 n n ethei is liiou^ht in contact with sodium 



ethylate in absolute alcohol. E. Duvillier. — Ann. Chim. 



I'hys., 19, 429. 



