5^4 



NA TURE 



[April i6, 1896 



In t\v(j papers which appear in English, in No. 22 of the 

 Commumcations from the Laboratory of Physics at the Univer- 

 sity of Leyden, Dr. P. Zeeman gives the results of the measure- 

 ments he has made on the absorption of electrical vibrations in 

 electrolytes. The method employed consists in starting oscilla- 

 tions in a Lecher wire system by means of a Blondlot oscillator ; 

 the wires passing for a part of their length through a trough 

 containing the electrolyte. In order to measure the energy of 

 the vibrations at any point of the wire, the arrangement employed 

 by Rubens, consisting of two very small Leyden jars, the outside 

 coatings of which are connected through a bolometer, is used by 

 the author. In a preliminary series of experiments, in which a 

 solution of sodium chloride having a conductivity 3'2 x 10"^ 

 times that of mercury was employed, it was found that, for 

 oscillations having a wave-length in air of 6-4 metres, and for 

 which the logarithmic decrement (the 7 of Bjerknes) was 0*34, 

 the intensity of the oscillations are reduced to i/<? of their initial 

 intensity after passing through 57 cm. of the solution. These 

 results were somewhat vitiated by the fact that the deflections of 

 the bolometer decreased as the jars were moved along the wires 

 in the electolyte, but instead of becoming zero they gradually 

 reach a constant value. The result given above was obtained by 

 diminishing all the readings by this constant amount. In a 

 subsequent series of experiments, in which the spark gap of the 

 primary oscillator was altered, this constant deflection was 

 practically eliminated. In this series experiments were also 

 made, using a solution of copper sulphate having the same 

 specific resistance as the solution of common salt, and it was 

 found that in both cases the intensity of the vibrations was 

 reduced to ije after passing through 5'i cm. of the electrolyte. 

 Hence, the author concludes that, in dilute solutions of different 

 electrolytes having equal conductivities, electrical vibrations of 

 the same period are equally absorbed. 



The velocity of an earthquake-wave within a short distance 

 from the epicentre is so difficult to ascertain on account of the 

 .large error resulting from a srhall error in the recorded times, 

 that all estimates with an approach to accuracy are of value. 

 In the Brescian earthquake of November 27, 1894, good time- 

 determinations were obtained at ten stations, all within 445 km. 

 from the epicentre. Assuming the velocity to be uniform in 

 all directions, Dr. M. Baratta calculates it to be f4ii km. per 

 second. Taking account of the nature and extent of the rock 

 traversed by the earth-wave, he also finds the average velocity to 

 be 782 km. per second in alluvium, and i "569 km. per second 

 in the older and more coherent rocks. 



A COUPLE of teeth found at Taubach, near Weimar, are 

 claimed by Dr. A. Nehring to be the oldest human teeth yet 

 found in Europe ( Verhandl. Berlin Anthrop. Ges., 1896, p. 573). 

 One of these is a milk molar, and the other a permanent first 

 molar of the left lower jaw. The crown of the latter measures 

 1 1 7 by 9 "9 mm. , and has three outer and two inner cusps, besides 

 minor cusps and folds ; in this, and in the occurrence of grooves 

 and holes in the outer side of crown, the tooth is remarkably 

 like that of the chimpanzee, but not much like that of the 

 gorilla or orang. Dr. Nehring calls attention to the fact that 

 the first pre-molar and last molar are reduced in size in modern 

 man as compared with early man, and he finds exactly the same 

 in domesticated, as compared with wild, dogs. In domesticated 

 dogs, as in civilised man, the jaw is relatively feebly developed, 

 and there is a tendency to reduction of the last molar. 



In the collection of mammals, made in connection with the 

 recent re-survey of the boundary line between Mexico and the 

 United States, are several which appear to be new to science. 

 In view of the probable delay in issuing the complete report 

 on these collections, advance sheets are being issued containing 

 •preliminary diagnoses of the new forms. In one of these sheets, 

 NO. I 38 I, VOL. 53] 



just received. Dr. E. A. Mearns describes as new sub-species 

 Sperniophihis mexicanus parvidens (Rio Grande Spermophile) 

 and S. harrisi saxicohis (Rock Spermophile). The common 

 "Jackrabbit" of the Rio Grande, described by Audubon and 

 Bachman, Baird, Allen, and other writers as Lepus callotis and 

 L. texianus, is taken to represent a new species, which has been 

 named L. merriami. Two new species of mouse, Peromyscus 

 camts (Texas grey mouse) and P. tornillo (Tornillo mouse), are 

 described, and two new sub-species, P. texanus medius (San 

 Dilgo-plains mouse) and P. t. cknientis (San Clemente mouse). 



Technical bacteriology has received an interesting addition 

 to its list of useful fermenting moulds, in the shape of a recent 

 contribution from Dr. C. Wehmer. At the instigation of and 

 with the assistance of Dr. Went, of Java, Dr. Wehmer has iso- 

 lated and carefully studied the organism responsible for the pro- 

 duction of the well-known Soja (Tao-Yu). So far, it appears to 

 have every right to be regarded as a novelty, although in some 

 respects closely allied to the Aspergilhis otyza of Japanese fame. 

 In designating this organism as Aspergillus Wentii, Dr. 

 Wehmer gracefully acknowledges Dr. Went's important share in 

 its discovery and identification. In artificial cultures it is readily 

 distinguished from its Japanese confrere, as it produces a pig- 

 ment approaching a light chocolate in colour, whilst the former 

 elaborates a greenish-yellow growth. The method adopted for 

 its collection is very simple, merely consisting in covering up 

 boiled beans, subsequentlysuperficially sun-dried, with the leaves 

 oi Hibiscus tileaats ; the much- valued Aspergillus then invariably 

 makes its appearance on the beans, and the usual process of 

 manufacture is then proceeded with. Curiously no other article 

 of food offers any attraction to the Aspergillus, beans alone 

 serving for its capture. This method of collecting the mould 

 exactly resembles that employed by the Chinese in their process 

 of arrak manufacture. The original memoir is accompanied by 

 some beautiful plates, and one of these shows verj* clearly the 

 different appearance on rice-cultures of the Aspergillus oryzcc and 

 the Aspergilhis Wentii respectively. 



We have received the first part of a Handbuch der praktischen 

 Zi/ninergdrlnerei, by Max Hesdorffer (Berlin : Oppenheim). It 

 appears to be a very complete practical guide to the indoor 

 cultivation of plants, published at a very low price (75 pf. when 

 complete). The present part contains a chromolithograph, and 

 a number of wood-block illustrations of utensils and of garden- 

 ing processes. 



The Rebman Publishing Company, Limited, have in the 

 press for publication a serial work exemplifying the uses of the 

 new photography in medical and surgical diagnosis, entitled 

 " Archives of Clinical Skiagraphy," by Mr. Sydney Rowland. 

 The first part will consist of six collotypes (10 by 12^ inches), 

 illustrating cases in which the method has been successfully 

 applied to elucidating obscure injuries to the knee, elbow, and 

 other parts of the body. The first plate is a skiagram of the 

 complete osseous system of a full-grown child — the largest subject 

 as yet done. 



A new local bi-monthly magazine — the Halifax Naturalist— 

 has made its appearance, its object being to publish information 

 concerning the natural history and archaeology of the ancient 

 parish of Halifax, and to record the doings of the Halifax 

 Scientific Society. The first number contains a coloured 

 geological map of Halifax, by Mr. C. E. Fox, and articles 

 on some physiographical features of the district, by Mr. W, j 

 Simpson ; the birds of the Luddenden Valley, by Mr. H. ; 

 Waterford ; and the flora of Halifax, by the editor, Mr. W. B. 

 Crump. Suoh a magazine should awaken interest in the wild life ; 

 of the parish to which it belongs, and lead to a keener and wider 

 appreciation of the works of nature. ' 



