September 14, 1891] 



NATURE 



481 



the Aniiatusite group may be noted. All these cases may be 

 capable of some other explanations, but I cite them to show 



\ that such excesses are commonly met with in published analyses. 



' On the other hand, it is scarcely to be doubted that a good 

 analyst, who obtained a really significant excess, would throw 

 such a result aside as erroneous and never publish it. I there- 

 fore plead for much greater care in analyses of the kind in ques- 

 tion, and closer scrutiny of results in the light of the suggestions 

 I have ventured to offer. It is probable that silicates contain- 

 in:; only partially oxidised aluminum are rare ; nevertheless the 

 ^circh for them would introduce a new element of interest into 

 mineralogical inquiries. 



If the general considerations I have now endeavoured to lay 

 before you are allowed their full weight, some of the alumino- 

 silicates of our primary rocks reveal to us more than we hitherto 

 supposed. Regarded from this newer standpoint, they are 



, teleoxidised representatives of substances which foreshadowed 

 in terms of silicon, aluminum, and oxygen the compounds of 

 carbon, nitrogen, and hydrogen required at a later stage of the 



' earth's history for living organisms. Thus, while the sedimen- 

 tary strata contain remains which come down to us from the very 

 flawnoflife on this globe, the rocks from whose partial dis- 



' integration the preserving strata resulted contain mineral records 

 which carry us still further back, even to Nature's earliest 

 efljrts in building up compounds similar to those suited for the 

 purposes of organic development. 



NOTES. 

 Prof. MaxMCller has attained the jubilee of his Doctorate, 

 having taken his degree in 1843, and in honour of the occasion 

 the University of Leipzig has conferred a new diploma upon 

 him. 



Mr. Bell, of Carlton Street, Nottingham, has brought out, 

 at an opportune moment, " A Contribution to the Geology and 

 Natural History of Nottinghamshire." The little volume is 

 edited by Mr. J. W. Carr, who in his preface records his in- 

 debtedness to various friends — specialists in certain depart- 

 ments — who wrote for him some portions of the book. The 

 book was compileJ at the request of the Local Excursions' 

 Committee of (he British Association, for the use of members 

 attending the Nottingham meeting. We have no doubt that 

 many such will avail themselves of the handy little guide-book, 

 which has been prepared for their special benefit. 



There seems 10 be no doubt that the latest report of the 

 death of Emin Pasha is to be relied upon. Mr. A. J. Swann, 

 of Uj'ji, from whom the report comes, declares that jp his 

 opinion it is as conclusive as anything cm be in Africa. And 

 now within a week of the tidings of Emin's death the sudden 

 decease is announced of another African traveller — Surgeon- 

 Major Parke— one of the most widely known of the members 

 of the Emin Relief Expedition. He died suddenly on the night 

 of Sunday last, while on a visit to the seat of the Duke of St. 

 Albans at Alt-na-Cralg. 



The death is announced, at the age of sixty-one, of Dr. 

 Alexander Strauch, the Director of the Zoological Museum of 

 St Petersburg. Dr. Strauch was an authority on reptiles, and 

 the author of several zoological works. 



The death is reported of Mr. T. W. Kennard, C.E., 

 onoder of the Monmouthshire Crumlin Works, designer and 

 constructor of the Crumlin Viaduct, and engineer-in chief of 

 the Atlantic and Great Western Railway, United States. He 

 died at the age of 68. 



'.'-E have to record the death of a well-known inventor and 

 li engineer of New York, in the person of Mr. Joseph Battin. 

 1 1 u was in his 87th year. 



j O.s and after November i next, the railway time throughout 

 [the kingdom of Italy will, according to a recent Act of the 



NO. 1246, VOL. 48] 



Legislature, be regulated by the mean solar time of the 15th 

 meridian east of Greenwich, this being the so called Middle 

 European time. The hours will be reckoned from midnight to 

 midnight. The new time will be II minutes in advance of the 

 mean solar time of Rome. It is expected that the other ser- 

 vices and the Italian public generally will soon follow the 

 example set by the railway stations. 



M. D'Arsonval, in E'edriciti for August 24, describes some 

 experiments which he has made on the eflfecls of stron^;, 

 alternating magnetic fields on animals, his results apparently 

 being somewhat contradictory to those recently obtained in the 

 Edison Laboratory. M. D'Arsonval's experiments were per- 

 formed by .means of coils wound ron cylinders of cardboard, 

 glass or wood, large enough to accommodate a man inside them 

 when required. The solenoid thus formed constituted the path 

 for the discharge of a condenser of two to twelve Leyden j.irs, 

 arranged in two batteries with proper precautions for rendering 

 the discharge oscillatory. The jars were charged periodically 

 by a transformer, giving a current at about 15,000 volts, with 

 a freq'iency of sixty per second. A lamp held with one 

 terminal in each hand of a man standing within the solenoid, 

 may then be raised by the induced currents to bright incande- 

 scence, while M. D'Arsonval asserts that considerable physio- 

 logical effects are also produced. The method used to deter- 

 mination the strength of these alternating magnetic fields is 

 very ingenious ; it consists simply in inserting a mercurial 

 thermometer in the field, and noting the rise of temperature 

 produced by the Foucault currents in the mercury. A con- 

 siderable rise is very quickly produced in the strongest field?, 

 while for weaker fields a petroleum thermometer is employed, 

 or an air thermometer the bulb of which contains a small 

 copper tube. 



Dr. W. S. Hedley, in an article in the Lancet, comments 

 on M. D'Arsonval's work, and mentions some experiments of 

 his own which seem to support the hypothesis that the harm- 

 lessness of high frequency alternating currents may be 

 explained by the fact that in these cases there is " virtually no 

 current strength"; e.g , a current of two amperes at 200 

 volts, if transformed up to 100,000 volts, cannot exceed in 

 strength O'oo4 ampere. Another factor concerned in the effect 

 is the " concentration " of the current. Passing a current of 

 high frequency and capable of keeping a 5 candle lamp glowing, 

 through the body by means of copper cylinders held in the 

 hands, produced no appreciable effect beyond a slig'it warming 

 under the electrodes; using a half-crown as electrode on the 

 forearm, the same negative result follows ; with a shilling, there 

 is a slight pricking effect, which becomes quite painful with a 

 threepenny-piece substituted for the shilling, thus indicating 

 that other factors have to be considered, as well as more 

 frequency, in the discussion of the " harralessaess " of alter- 

 nating currents. 



The issue in a compact form of the interesting series of 

 articles on " Sewage Purification in America," by M. N. Baker, 

 which appeared in the Engineering News of New York last 

 year, furnishes an important ad lition to our information on 

 this complicated subject. The treatment of the sewage of thirty 

 municipalities in the United States and Canada is given in 

 detail, and the description further elucidated by no less than 

 seventy-seven illustrations, including elaborate plans showing 

 the various arrangement of purification, plant, &c. The little 

 pamphlet of 195 pages is well printed and is provided with a 

 copious index. That America has recently devoted much 

 attention to the vexed question of the purification of sewage 

 will be remembered by all who have had occasion to consult 

 the admirable experim;ntal work on the chemical and bacterio- 



