45^ 



NA TURE 



[September 6, 1894 



metals were employed, allojs were formed, which, in the case 

 of lead and tin, were fusible and flowed out at iSo . By 

 placing a perforated disc of mica between the two, the oulflow 

 could be prevented, but the alloy formed at the centre and the 

 metals were hollowed out in the proportion of their degrees of 

 liquefaction. In a lead-antimony couple, the hole in the lead was 

 8mm. or 9 mm., and that in the antimony 2 mm. The most 

 striking and novel experiments, however, were those showing 

 the evaporation of metals, or rather their sublimation, at tem- 

 peratures between 300° and 400' . This was also shown by 

 inserting a disc of mica, say, between a zinc and copper 

 couple at 360°. When air wa> carefully kept away from the 

 surfaces, the copper was tinted a golden yellow over the area 

 of the hole in the mica, the exact colour of tombac, and a 

 brown layer was produced on the zinc, which chemical analysis 

 proved to contain copper. Similar results were obtained with 

 cadmium, the thickness of the mica being O'S mm. 



We have received a copy of the yahra-Bericht lics Vereitis 

 Jiir Naturkuna/ of Mannheim, in which a brief account is given 

 of the proceedings of the Society during the years 18S9-93 

 inclusive. It appears that in spite of the population of Mann- 

 heim having doubled itself during the past eighteen years, the 

 Society has not increased in numbers. That it should have 

 maintained a bare existence must be considered very creditable 

 to the energy of its members, for we read that Mannheim, as 

 perhaps no other commercial or industrial centre, possesses so 

 few attractions in the shape of social or scientific intercourse 

 that the inhabitants as soon as they can retire from work leave 

 the city to settle elsewhere. .\ similar nemesis unfortunately 

 overtakes some of our local naturalist societies, and Mannheim 

 cannot claim the unique position ascribed to it by the president 

 of its Naturkunde Verein ! The greater part of the pamphlet 

 is occupied by an elaborate paper, by Dr. Migula, entitled 

 ■ Methode und Aufgabederbiologischen Wasseruntersuchung. " 

 The endeavour is made to build up a bacteriological standard 

 of purity for water, not according to the number of microbes, 

 but from an estimation of the particular varieties present in a 

 given sample of water. We arc not surprised to find Ur. Migula 

 willing to resign this herculean task to others to work out. 



Mr. W. .\. San FORD read before the Somerset .Vrchaso- 

 logica! and Natural History Society, at its late meeting at 

 I^ngport,a paper in which he announceil his discovery, in the 

 Rhxtic beds at Wedmore, of a large Dinosaur. The animal 

 appears to have been carnivorous, and, though very much 

 larger, to have resembled Megalosaurm Bucklandi of the 

 Stonesfield slate. The remains at present available for study 

 are about twelve vertebr.x, a large portion of the pelvis, 

 •ome portions of the mandible, some teeth, a nearly complete 

 femur, parts of a tibia and of both fibulx, some phalanges, 

 including a perfect claw-bone, and fragments of ribs and of other 

 small b'incs, and other larger fr.agments that may be placed. 

 The bone» are accompanied by fossils of Triassic dale, which 

 render their geological position a matter of nearly absolute 

 certainty. The results of a complete and close examination 

 of the l>ones will be of considerable interest. 



In .iddilion to a preliminary note on some new species of 

 fish, belonging to the genera Characodon and Alhcrinichlhys, 

 from the Mexican Seas, by Dr. F. Stcindachnrr, the June 

 number of the Procetiiings of the Imperial Academy of Science 

 of Vienna (1894, N"- "*• PP- "47 '54* contains a communica- 

 tion from Prof. Weisncr upon the results of a physiological in- 

 vestigation upon some interesting points in the germination of 

 the mistletoe and its European .and tropical allies {yis.iim and 

 f^ranlhus). The author finds a considerable difference 

 between the seeds of the European and tropical forms as regards 

 NO. 1297, VOL. 50J 



their reaction to light and moisture, and as to the existence or 

 duration of a "resting period." These differences and 

 peculiarities, however, he is in all cases able to interpret as 

 specific adaptations to differences in the natural conditions of 

 life. The viscid envelope of the seeds in all the parasitic 

 species is undoubtedly an adaptation for ensuring the att.ach- 

 ment of the seed to the bark of its host ; but Prof. Weisner 

 reg.ards its great development in the common mistletoe ( I'iscitm 

 aWum) as also serving to retard the process of germination. 

 There is practically no resting period in the case of the tropical 

 species, and in them the viscid pericarp is developed in much 

 smaller quantity ; and the seeds of our own I'iscnm album 

 germinate most re.idily when freed from their mucilaginous in- 

 vestment. It is to be hoped that Prof. Weisner will publish 

 before long a fuller account of his interesting researches, and 

 that he will also incorporate some statements as to the effects 

 of temperature upon the germination of the same seeds. 



I.N an elabor.ile paper " Ktndeexpurimentale sur le charbon 

 symptomatique " {Annales de rinsliliil PasUiii), Dr. Duensch- 

 mann describes some extremely interesting and suggestive 

 experiments which he has made on the effect of associating a 

 virulent with a non-virulent micro-organism in animal inocula- 

 tions. For this purpose the well known bacillus />;Wi>ii'i«j was 

 introduced into guinea-pigs along with the bacterium C/iativoi, 

 the exciting cause of symptomatic anthrax. Under ordinary 

 circumstances the latter microbe will kill guinea pigs in eighteen 

 hours, but, strange to say, its lethal action is delayed for four 

 days, when it is associated with the />'. fyroiiigiosus. M. Roger 

 already found that the rabbit, an animal not easily susceptible 

 to symptomatic anthrax, may be readily infected if cultures of the 

 J>. prodigiosus are introiluced along with the P. C/iiinitvi, and 

 similar observations in the case of other disease microbes, 

 associated with this harmless bacillus, have been made by others. 

 Dr. Duenschmann, however, has carried his investigations still 

 further, and has found that the B. /irodigiosiis, usually regarded 

 as an innocent saprophyte, will, if used in sufficient quantities, 

 kill guinea-pigs when introducedinto the peritoneum. The chief 

 interest of Dr. Duenschmann's experiments lies in the contribu- 

 tion which they afford to the important subject of the (WJ<»(-((i^frf 

 action of micro-organisms. The bacteriological study of disease 

 has so far been mainly carried on with single varieties of 

 microbes ; but it must not be forgotten that in nature infection 

 with a pure culture, or one variety of organism, is the exception 

 and not the rule, and that in working with mixtures of micro- 

 organisms we may obtain much important assistance in under- 

 standing the intricate and puzzling course run by so many 

 diseases. 



The annual report of the Russian Geographical Society for 

 the year 1893 is so full, that only in a publication specially 

 devoted to geography would it be desirable even to enumerate 

 the headings of its varied contents. All we can do is to 

 mention the parts which possess general interest. Such are 

 the remarks of M. Obrucheff on the Eastern Gobi between 

 Urga and Pekin, which has the characters of a steppe, but not 

 of a desert, as it receives a regular amount of rain in the 

 summer, aud is covered then with grass, while true deserts are 

 found in small limited portions imly of its vast area. M. 

 Obrucheff's find of a skull of a rhinoceros, probably 7'ichor/iiniis, 

 in the lake deposits of the Ordos, in latitude 38" N., is also 

 worth mentioning. E. G. Fritsche's measurements of the 

 magnetic elements in the neighbourhood of Moscow, where an 

 anomalous distribution had been observed, show that the 

 anomaly is due to the presence, at a depth which is cstimalcd 

 at ten kilometres, of large iron masses. M. IComarolf's 

 measurements of the movement of the Zerafshan glacier and 

 the exploration nf its former much greater extension, as 



