240 



NA TURE 



[January 4., 1894 



qralings, by M. A. Cornu. The verification of the theory of 

 focal anomalies in gratings already published, by testing actual 

 gratings showing such anomalies, was based upon the following 

 theorem : When the observed pencils make a constant angle 

 with the incident beam remaining fixed, half the sum of the 

 azimuths of the grating corresponding to spectra of symmetric 

 orders is constant, and equal to the azimuth corresponding to 

 the reflected beam. — Remarks on the spontaneous heating and 

 ignition of hay, by M. Berlhelot. Hay dried and stacked under 

 norma! circumstances loses moisture and oxidises slowly, with- 

 out being sensibly heated. The initial heating, where it takes 

 place, is due to the action of ferments, but not the higher stages 

 of the process. When the ferments are no longer capable of 

 further raising the temperature without endangering their own 

 existence, it often happens that purely chemical action steps in, 

 and leads up to the ignition of the haystack. The temperature 

 of ignition for these materials is far below red heat. — On the 

 composition of winter drainage waters from bare and from culti- 

 vated soils, by M. P. P. Deherain. — Observations of the minor 

 planets 371 and 372 (1893) made with the great equatorial of 

 the Bordeaux Observatory, by MM. G. Rayet and L. Picart. — 

 The analysis of comm.ercial butters, by M. C. Viollette. — On 

 the approximate development of the disturbing function in the 

 case of inequalities of higher orders, by M. M. Hamy. — Investi- 

 gation of that part of the coronal atmosphere of the sun which is 

 projected upon the disc, by M. H. Deslandres. — Is there oxygen 

 in the sun's atmosphere? by H. Duner. — New applications of 

 the tables of increasing latitudes to navigation, by M. E. Guyon. 

 — On the successive radii of curvature of certain curves, by H. R. 

 Godefroy. — Calculation of electro-magnetic forces, according to 

 Maxwell's theory, by M.Vaschy. — On the diurnal variation of the 

 tension of aqueous vapour, by M. Alfred Angot. The observations 

 made at the top of the EifYel Tower since the end of 1889 have 

 shown that at the height of 300 m. the change of vapour tension 

 during winter does not exceed a few hundredths of a mm. 

 During the eight months beginning with March, a single 

 maximum was observed during the day at 9 a.m., and a 

 minimum at 5 p.m., while in the adjacent Pare SaintMaur, 

 there were two maxima, at 9 a.m. and 8 p.m., and two minima, 

 at 4 a.m. and 4 p.m. It appears that the variation of vapour 

 tension, as observed in ordinary meteorological stations, is a 

 local phenomenon, limited to the lower strata of the atmosphere. 

 — On the diurnal variation of atmospheric electricity, observed 

 near the summit of the Eiffel Tower, by M. A. B. Chauveau. 

 The indications of an electrometer registering photographically 

 the potential of the air, lead to conclusions similar to those of 

 the preceding paper. The two sets of maxima and minima 

 observed on the ground are replaced by one set only, con- 

 sisting of a maximum at about 6.30 p.m. and a minimum at 

 4 a.m. The potential, which sometimes exceeded 10,000 volts, 

 was reduced to a convenient amount by the interposition of con- 

 densers in cascade. — On the weight of a li>re of normal air, and 

 the density of gases, by M. A. Leduc. — Skeich of a system of 

 atomic weights of precision, founded unon the diamond as 

 standard substance, by iVI. G. Hmrichs. — General method for 

 the volumetric e timation of silver under any form, by M. G. 

 Deniges. — On the stability in air of a O'ooi solution of corrosive 

 sublimate, by M. Tanret. — Remarks on the critical pressures in 

 the homologous series of organic chemistry, by M. E. Mathias. 

 — On caseineand the organic phosphorus of caseine, by M. A. 

 Bechamp. — On a new source of rhodimil, by MM. P. Monnet 

 and Ph. Barbier. — Presence of camphene in essence of aspic, by 

 M. G. Bouchardat. — On the volatile carbides of the essence of 

 valerian, by M. Oliverio. —Contribution to the study of the 

 ptomaines, by M. CEchsner de Coninck. —Influence of certain 

 causes upon receptivity ; bactenan associations, by M. V. 

 Gattier. — Toxicity of the binod of the viper ( Viperaaspis L). — 

 Modifications of the emissive powt-r of the skin unner the in- 

 fluence of the electric brush di-charge, by M. Lecercle. — In- 

 fluence of iron upon ihe vetjetation of barley, by M. P. Petit. — 

 Influence of I'aik-strippirg upon the mechanical propr-rties of 

 wood, by M. E. Mer. — On ihe natural dessication of grains, by 

 M. II, Coupin. — On the oolitic strata of the Paris Tertiary, by 

 M. G. F. DolHus. 



Berlin. 

 Physiological Society, December 8. — Prof. Munk, Presi- 

 dent, in the chair. — Prof. A. K'>s el gave an account of his 

 further researches on nucleic acid, carried on in conjunction 

 with Dr, Neumann. I he acid, as obtained from the thymus, 

 differs from that obtained from other sources, in that during its 

 decomposition it yields only adenin ; it has hence been dis- ' 

 NO. 1 262, VOL. 49] 



tinguished as adenylic acid. It occurs in two forms : one 

 readily soluble, the other soluble with difficulty. When boiled 

 with water, this acid yielded a paranucleic acid, which con- 

 tained no adenin. By boiling with dilute hydrochloric acid a 

 fourth acid (ihyminic) was obtained, from which crystalline 

 thymin could be obtained. All the above well-characterised sub- 

 stances possess, when analysed, an extremely complex constitu- 

 tion ; thus the molecule of adenylic acid contains 75 atoms of 

 carbon, and that of paranucleic acid 90 atoms. Dr. H. Kossel 

 had studied the action of nucleic acid on bacteria, and found 

 that cholera-germs and streptococci are readily killed by small 

 quantities of the acid ; whereas anthrax germs are much more 

 resistent. He therefore considered that the bactericidal action 

 of lymph-cells was attributable, in part at least, to this action . 

 of nucleic acid. — Dr. Rawitz spoke on spermatogenesis in 

 Hydromedusre. Unlike all other animals, the spermatozoa in 

 this animal are developed in the outer layer of the bell, and are 

 discharged direct into the surrounding fluid. The same speaker 

 further described curious large branching villi in the jejunum of 

 Macacus, not met with in the intestine of other species of 

 monkey. 



BOOKS PAMPHLETS, and SERIALS RECEIVED. 



Books. — The Canadian Ice Age: Sir J. W. Dawson (Montreal). — The 

 Genus Salpa. 2 Vols., Text and Plates : Prof. W. K. Brooks (Baltimore). — 

 The Butterflies and Moths of Teneriffe : A. E. H. White (L. Reeve) — 

 Journal of Microscopy and Natural Science, Vol. 3, Third Series (Baillicre). 

 — Linnean Society of New South Wales, the Macleay Memorial Volume : 

 edited by J. J Fletcher (Dulau). 



P.\MPHUETS. — Origin of the Pennsylvania Anthracite : J. J. Stevenson 

 (Rochester). — On the Use of the Name "Catskill": J. J. Stevenson 

 (Rochester).— The Marsh Warbler, &c. : W. W. Fowler (Oxford, Black- 

 well). — On Technical Education in Glasgow and the West of Scotland : 

 H. Dyer (Glasgow). — Imperial Institute Series, Handbooks of Commercial 

 Products, Indian Section, Nos. 1-22, 24-25, 27-29 (Calcutta). — Guides to 

 Commercial Collections, Indian Section, No. i (Calcutta). — Agricultural 

 Ledger Series, Nos. 1-13 (Simla). 



Serials. — Bulletin de 1' Academic Royale des Sciences de Belgique, '' ; 

 Annee, No. 11 (Bruxelles). — Journal de Physique, December(Paris). — Zeit- 

 schrift fiir Physikalische < hemie, xii. Band, 6 Heft (Leipzig). — Zeitschrift 

 fiir Wissenschaftliche Zoologie, Ivii. Band, i Htft (Leipzig) — Bulletins de 

 la Soci6tc d'AnthropoIogie de Paris, December 15 (Paris). — Verhandlungen 

 des Gesellschaft fiir Erdkunde zu Berlin, Band xx. Nos. 8 and 9 (Berlin).^ 

 Verhandlungen der Gesellschaft fur Erdkunde zu Berlin, Bandxxviii. No. 4 

 (Berlin) — American Naturalist. December (Philadelphia). — Journal of the : 

 Royal Agticultural Society of England, Third Series, vol. iv. part 4 (Murray), i 

 — L' Astronomic, January (Paris). — 1 he Asclepiad, No. 39, vol. x. (Long- 

 mans). — Geological Magazine, January (K. Paul). — Seances de la Socictc- 

 Francaise de Physique, April-July, 1893 (Paris). 



~ CONTENTS. PAGE 



Recent Contributions to Meteorology 217 



Physico-chemical Measurements. By J. W. 



Rodger 219 



Our Book Shelf:— 



Cooke : " Handbook of British Hepaticre." — 



C. H. W 220 



Lydekker: " The Royal Natural History " .... 220 

 Letters to the Editor : — 



The Origin of Lake Basins.— Dr. Alfred R. Wal- 

 lace.F.R.S.; Sir Henry H. Howorth, K.C.I. E., 



M.P., F.R.S 220j 



Hindoo Dwarfs.— Surgeon-Captain A. E. Grant . 221 i 

 Ewart's Investigations on Electric Fishes. By 



Prof. Gustav Fritsch 222 



Navigation by Semi-Azimuths. By G 223 



Voices from Abroad. By Prof. Henry E, Armstrong, 



F.R.S 225 



The Effects of Light on Electrical Discharge. By 



W. W 226 



Neolithic Discoveries in Belgium. By J. E. ... 227^ 



The Late Sir bamuel Baker 227! 



Notes 228| 



Our Astronomical Column : — 



Prizes at the Paris Academy 233 [ 



The Tail of Comet Brooks (^ 1893) 2331 



The Planet Venus 233! 



Geographical Notes 233 



New French Law for the Prevention of Forest 



Fires. By Prof. W. R. Fisher . . .... 2 



Prize Subjects of the Paris Academy of Sciences . 234 



Science in the Magazines 235 



The Rise of the Mammalia in North America. I. 



( Wifh Diagram.) By Prof. H. F. Osborn 235 



Scientific Serials 238 



Societies and Academies 235 



Books, Pamphlets, and Serials Received 24c 



