72 



SCIENCE. 



[Vol. XV. No. 365 



NOTES AND NEWS. 



The way in which foreign plants become ' ' weeds, ' ' under 

 new and favorable conditions, is illusti-ated by the recent case of 

 Melilotus alba in our Western States. Introduced a few years 

 ago as a garden-plant, it has spread so rapidly in the rich bottom- 

 lands along the Missouri River, according to Garden and Forest, 

 that it is fast driving out the sunflower and other native weeds. 

 It is commonly called the ' 'Bokhara clover. ' ' 



— A meteorite of special interest to chemists has been exam- 

 ined by M. Stanislas Meunier. It fell at Mighem, in Russia, 

 on June 9, 1889; and- it was evident, from a cursory inspection, 

 that it was of a carbonaceous nature. In external appearance, as 

 stated in Nature, it exhibited a deep greenish-black color, 

 relieved by numerous small brilliant white crystals. The sur- 

 face was considerably wrinkled, and blown out into swellings. 

 The material was very friable, and readily soiled the fingers. 

 A section under the miscroscope was observed to consist largely 

 of opaque matter interspersed with crystals of a magnesian 

 pyroxene and peridote. Fine particles of metallic iron and 

 nickeliferous iron were readily collected by a magnet from the 

 powdered rock, having all the characteristics of meteoric iron. 

 The density of the meteorite was not very high, 2.495. About 

 85 per cent of the rock was found to be attacked by acids, the 

 portion so attacked being shown by analysis to consist mainly 

 of a silicate of magnesium and iron having the composition of 

 peridote. On the remaining 15 per cent being heated in a cur- 

 rent of dry oxygen gas, it readily took fire and burnt brilliantly. 

 The products of combustion, which were allowed to pass through 

 the usual absorption tubes containing pumice and sulphuric acid 

 and potash, showed that the meteorite contained nearly 5 per 

 cent of organic matter. In order to obtain some idea as to the 

 nature of the carbonaceous substance present, a quantity of the 

 rock was powdered and then digested with alcohol. On 

 evaporation the alcholoic extract yielded a bright yellow resin, 

 which was readily precipitated from the alcoholic solution by 

 water, and much resembled the kabaite of Wohler. The most 

 curious chemical properties of the meteorite, however, are 

 exhibited with a cold aqueous extract of the powdered rock. 

 The filtered liquid is quite colorless, but exliales a faint odor 

 due to an organic salt which carbonizes on evaporation to 

 dryness, and may be burnt upon platinum foil. The aqueous 

 extract further contains nearly 2 per cent of mineral matter 

 possessing properties of a novel character. Barium-chloride 

 solution gives a heavy white precipitate, which, however, is 

 not barium sulphate. Silver nitrate gives a voluminous curdy 

 reddish-violet precipitate, reminding one of silver chromate, 

 but of quite a distinct and peculiar tint, and which blackens 

 in a very few minutes in daylight. The substance which 

 exhibits these re-actions is unchanged by evaporaticm to dryness 

 and ignition to redness, readily dissolving in water again on 

 cooling, and giving the above re-actions. The silver-nitrate 

 precipitate, when allowed to stand for some time undisturbed 

 in the liquid, becomes converted into colorless but brilliantly 

 refractive crystals, which polarize brightly between crossed 

 nicols under the microscope, and which are insoluble in 

 boiling water. The properties of this new substance contained 

 in the water extract appear to approximate most closely to 

 those of certain metallic tellurates, but the new compound ap- 

 pears also to differ in certain respects from those terrestrial salts. 



— We owe a new and interesting application of photography to 

 M. Bertillon, the well-known director of the Identification 

 Department at the Paris Prefecture of Police. M. Bertillon has 

 been devoting himself for some months to the study of the 

 physical peculiarities engendered by the pursuit of different 

 occupations. According to Nature, tiie police have frequently 

 to deal with portions of bodies and it would greatly aid their 

 investigations to be able to determine the calling of the 

 murdered person in each particular case. The hand is, as a 

 rule, the part naturally most affected by the occupation; and 

 M. Bertillon has taken a very large series of photographs, each 

 one showing on a large scale the hands, on a smaller scale the 

 whole figure of the workman at his work, so that one may see 



at a glance the position of the body, and which are the parts 

 that undergo friction from the tools in use. From the hands of 

 the navvy all the secondary lines disappear, and a peculiar 

 callosity is developed where the spade-handle rubs against the 

 hand ; the hands of tin-plate workers are covered with little 

 crevices produced by the acids employed; the hands of lace- 

 makers are smooth, but they have blisters full of serum on the 

 back and callosities on the front part of the shoulder, due to 

 the friction of the straps of the loom ; the thumb and the first 

 joints of the index of metal-workers show very large blisters, 

 whilst the left hand has scars made by the sharp fragments of 

 metal. Experts in forensic medicine (Vernois among others) 

 have before drawn attention to the subject; but this is the 

 first time that an investigation has been carried out on a large 

 scale, and in M. Bertillon' s hands it should lead to the best 

 results. 



— Two new expeditions are announced in Globus, Bd. 6.'5, 

 No. vi. Joseph Martin has lately left Peking with a few 

 companions for Lan-chow and Sin-ning, with the intention of 

 reaching Tibet by the country of the Kuku Nor. The journey 

 is undertaken for the purpose of geological and physical 

 geographical investigations. This traveller is famous for his 

 great journey m eastern Siberia, and in particular for his ascent 

 of the Stanovoi Mountains. The well-known French traveller, 

 Bonvalot, accompanied by Prince Henry of Orleans, has com- 

 menced a new journey in Asia, the aim of which is nothing less 

 than to traverse the continent from north-west to south-east. 

 The expedition is to proceed from Omsk through Semipalatinsk 

 to Chuguchak on the Chinese frontier, then by Manas, Urumtsi,. 

 Karashar, Korla, the Lob Nor, Chamuen-Tai, Kukusai on the 

 upper Yang-tsi-kiang, Tsiamdo, Batang, and Yunnan, to the 

 coast at Tong-king. M. Bonvalot is, however, quite aware that 

 his plan may very probably have to be considerably modified. 



— The grass knovm as ' 'Lalang' ' {Imjxrata cylindrica) gives 

 the foresters of the Malay Peninsula more ti'ouble than our own 

 pi'airie-grasses give the tree-planters of the West. This Lalang 

 is injurious, says Garden and Forest, by reason of its inflamma- 

 bility, and because it prevents any cultivation of the land cov- 

 ered by it, except at great expense. Wherever land is allowed to 

 run to waste, it is soon covered with this grass, except where 

 the soil is wet, or sandy, or shaded by trees. The annual report 

 of the conservator of forests at Singapore refers at great length to 

 this plant, stating that it can be exterminated by chemicals ; but 

 these are expensive, and have an injurious effect upon the trees 

 planted in forest upon the land afterward. When trees are large 

 enough to tlu-ow a shade, the Lalang quickly disappears, and it 

 cannot penetrate into forest glades if but a few ti'ees bar its 

 progi'ess. The gradual planting of bushes and shade-trees is 

 recommended as the surest remedy for this grass pest. 



— An interesting study has been lately made by Herr Tar- 

 chenoff (PJiuger's Archiv) of electric currents in the skin fromi 

 mental excitation. Unpolarizable clay-electrodes, connected 

 with a delicate galvanometer, were applied to various parts, — 

 hands, fingers, feet, toes, nose, ear, and back; and, after com- 

 pensation of any currents which occurred during rest, the effects 

 of mental stimulation were noted. Light tickling with a brush 

 causes, after a few seconds' period of latency, a gradually 

 increasing strong deflection. Hot water has a like effect; cold 

 or the pain from a needle-prick, a less. Sound, light, taste, 

 and small stimuli act similarly. If the eyes have been closed 

 some time, mere opening of them causes a considerable deflection 

 from the skin of the hand. Different colors here aeted 

 unequally. It is remarkable that these skin-currents also 

 arise when the sensations are merely imagined. One vividly 

 imagines, for example, he is suffering intense heat; and a 

 strong current occurs, which goes down when the idea of cold is 

 substituted. Mental effort produces currents varying with its 

 amount. Thus, multiplication of small figures gives hardly any 

 current; that of large, a strong one. If a person is in tense 

 expectation, thegalvanometer mirror makes irregular oscillations. 

 When the electrodes are on hand or arm, a voluntary move- 

 ment, such as contraction of a toe or convergence of the eyes,, 



