494 



NATURE 



{March 20, 1884 



sense of rectitude ! Can we marvel that between two such 

 natures, so ditfevently ordered, and yet so complementary, there 

 shoulil ripen a friendship which both should reckon as the 

 greatest gain of their lives ? " 



Who can fully gauge the influence of such a nature as 

 Wohloi's? How it was exerted on Liebigj is indicated in the 

 following letter : — 



" FREDERICli WOHLER TO JUSTUS LlEBIG 



" Gotliiigeit, March 9, 1S43 



" T(i make war against Marchand, or, indeed, against anybody 

 else, brings no contentment with it, and is of little use to 

 science. . . . Imagine that it is the year 1900, when we are 

 both dissolved into carbonic acid, water, and ammonia, and our 

 ashes, it may be, are part of the bones of some dog w hich has 

 despoiled our graves — who cares then whether we have lived in 

 peace or anger ; who thinks then of thy polemics, of the sacrifice 

 of thy health and rest for science ? — Nobody. But thy good 

 ideas, the new facts which thou ha^t discovered, these, sifted 

 from all that is immaterial, will be known and remembered to 

 all lime. But how comes it that I should advise the lion to eat 

 sugar ! " 



It was thus in philosophic contentment, happy in his work, 

 in his home life, and in his friendships, that Wohler lived out 

 his fourscore years and two. He made Gottingen famous 

 as a school of chemistry ; at the time of the onc-and-tw»ntieth 

 year of his connection with the university it was fmnd that 

 upwards of 8000 students had listened to his lectures or 

 worked in his laboratory. He was a man whom the world has 

 delighted to honour ; and there was hardly an academy of science 

 or a learned society which has not in some way or other recog- 

 nised his services to science. lie was made a Foreign Member 

 of the Royal Society in 1S54, a Corresponding Member of the 

 Berlin Academy in 1855, Foreign Associate of the Institute of 

 France in 1S64, and in 1872 he received the Copley Medal from 

 the Royal Society. On September 23, 1882 — 



METEORIC DUST 

 C IR WILLIAM THOMSON has sent us the following com- 

 ■-^ munication for publication : — 



" Por/kil, Kikrcggan, March 13, 1 884 

 "Dear Sir W'illi.\m Thomson, — Herewith I inclose some 

 of the meteoric dust collected on a cotton filter, and both 

 ignited at a' i-ed heat. The change of colour is interesting. 



"On Sauirday, March i, the snow lay Si inches deep at 

 8 a.m., pure and white. At 9. 15 a.m., when I next noticed it, 

 It was .sooty looking, the blacliish appearance penetrating half 

 an inch only. The sky was clear and calm, any tendency to 

 movement of the air being from the south-east. 



" I carefully measured a superficial foot on an ontlying field 

 sloping to the south-wc-t at a spot bisected by the 200-foot line 

 of the Ordnance Survey, and collected the snow into two bowds 

 of white delft, half into each. After evaporating the snow 

 water, thoroughly drying the residue, I collected and weighed it, 

 that from one giving I J grains, and the other 2 J grains, or 

 4 grains to the square foot exactly. 



' ' I can personally vouch for the dust being all over the 

 Roseneath peninsula, as I trudged through the snow to Coulport 

 on Loch Long, and found it the same all the way north, also on 

 the top of the Gallow-hill (414 feet). I have since seen those 

 who noiiced it at Garelochhead, so that on this peninsula alone, 

 taking 4 grains as an average, there has fallen over 100 tons. 



" From hearsay it appeai-s to have been noticed from Kippen 

 on the north to Largs on the south, and from Hamilton on 

 the ea-^t to Dunoon on the west, or over an area (in round 

 numbers) of 810 square miles, and admitting the former esti- 

 matj, we have the astonishing aggregate of say 5760 tons ! A 

 weighty gift to Mother Earth, surely of some value. 



" I should mention that every crack, scratch, or depression in 

 the glaze of the bowls was filled with the finely divided matter ; 

 it was impossible, therefore, to collect it all for weighing, con- 

 sequently 4 grains per square foot is under rather than over the 

 probable average. The observer at Kippen, too, mentions that 

 the snow was permeated there for one inch by the sooty 

 appearance. 



" On Monday (March 3), after snow had fallen to the depth 

 of an additional 8 inches, I watched for a recurrence of the 

 phenomenon, and on the sky clearing about midnight I fetched 

 in a dish that I had left outside and found a little had fallen in 

 small flakes ; these had melted their way through the snow, 

 leaving Utile tunnels about the size of crow-quills. The quantity, 

 however, was exceedingly small. Tendency to movement of the 

 air as before from the south-east. Barometer had risen from 

 29'4 at 2 p.m. to 29'6, steady at midnight, thermometer 42°. On 

 .Saturday previous barometer stood at 30'o5 (90 feet above sea- 

 level, aneroid), thermometer 44°, 12 noon. The dust I left with 

 you previously contains a little organic matter (grassy fibre), 

 though what I had under the microscope appeared entirely 

 metallic. 



"The snow had melted a good deal before I recognised the 

 importance of obtaining a fair sample. My children, however, 

 had rolled a huge snowball down the slope, at the top of which 

 the cottage stands, and this had increased as it rolled until it was 

 something like 6 feet in diameter, and so foruied a mine from 

 which to collect the dust. There is still some of the black w ater 

 in process of evaporation ; should you require it more of the dust 

 is at your service. 



"Oiie of the older inhabitants remembers a similar occurrence 

 here in 1828 on the 20th or 22nd of March, when the snow, he 

 says, fell in black or sooty flakes. 



" Perhaps it is well to mention that the goats suffered some- 

 what from influenza on .Sunday and Monday, and that I myself 

 had a sharp attacl; followed by severe headache for a day, caused 

 prolially by inhaling a minute quantity of the dust snufif fashion. 

 It might have oeen from something else, only the coincidence is 

 suggestive of caution. 



" I am, yours faithfully, 



" Lewis P. Muirhead 



"Professor Sir William Thomson, Glasgow University" 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGEiXCE 



Cambridge. — The Boards for Medicine, Physics and Che- 

 mistry, and Biology and Geology, after joint deliberation, 

 have recommended an important change in the appointments of 

 Natural Science Examiners. It has been a regulation of the 

 Natural Science Tripos that all answers shall be looked over by 

 two examiners out of the eight, but it has become increasingly 

 difllcult to find examiners with the requisite extent of know- 

 ledge. Thus it practically happens that each examiner is sole 

 examiner in a single subject, and the places of candidates 

 are often practically dependent on the judgment of a single 

 examiner to an extent unknown in the other Triposes. It is 

 now recommended that two examiners shall be appointed in 

 each subject of Natural Science, to undertake all the University 

 I^xaininations in that subject, and thus the Natural Sciences 

 Tripos, the Special Examinations for the ordinary B.A., and 

 portions of the M. B. Examinations, will be brought into one 

 system. The examiners should never both be changed at the 

 same time. The payments recommended are — for each examiner 

 in Physics and in Chemistry, 50/. ; in Botany, Zoology, Human 

 Anatomy, and Physiology, 40'. ; in Geology, 20/. ; and Miner- 

 alogy, lo/. 



SCIENTIFIC SERIALS 



yonntal of the Franklin Institute, No. 697, January. — W. 

 Dennis Marks, note on the losses per horse-power by condensa- 

 tion of steam in pipes and cylinders of engines. — De Volson 

 Wood, the cheapest point of cut-off. — Prof. R. H. Thurston, 

 the theory of turbines. This is the conclusion of a very valuable 

 mathematical paper given in a very full abstract. — B. N. Clark, 

 water-line defence and gun shields for cruisers. — W. Dennis 

 Marks, economy of compound engines. — Prof. E. J. Houston, 

 the Delany synchro nous-niulti|-ilex system of telegraphy. This 

 invention is founded on La Cour's phonic wheel, and bids fair 

 to supersede harmonic multiple telegraphs. 



Annalcn der Physik und Chemie, xxi. January. — O. Frohlich, 

 measurements of sun-heat. Describes amongst other matters a 

 new pyrheliometer with a special thermopile arrangement. — 

 A. W'. Velten, the specific heat of water. The results confirm 

 Regnault's values. — E. Pirani, on galvanic polarisation. Tire 

 values are estimated by a compensation method. — W. Hittorf, 



