502 



NA TURE 



[March 23, 1899 



MaNi HF.SI KR. 



Literary and Philosophical Society, I'Vbruary 21. — Mr. 

 I. Cosmo Mclvill, I'resident, in the chair. — Dr. C. II. Lees gave 

 ;in account of some preliminary experiments on the effect of 

 pressure on the thermal conductivities of rocUs and other sub- 

 stances, which he had undertaken with the view of providing 

 data for a recalculation of the age of the earth by Lonl Kelvin's 

 method. The experiments showed that there was a slight 

 tendency for the thermal conductivity to increase with pressure, 

 whicli would render necessary a small lowering of the earth's 

 age given by Lord Kelvin.— On the plague in Uganda, by the 

 Right Rev. Bishop Ilanlon (Uganda). The author described 

 the plague, which is known by the natives as " kaumpuli," as 

 l)eing akin to the black plague which once scourged London. 

 It begins suddenly, there is high fever, and a swelling, usually 

 under the armpit. Like many plagues, it has both a mild and 

 virulent form. The first is not attended with much fever ; 

 the swelling moves about the body, and, should it get near the 

 heart or into the throat, death may ensue. In the virulent form 

 Ihc swelling seems stationary, either under the armpit or in the 

 fork of the legs, whilst the patient dies if not speedily attended 

 to, this being the case with many sufferers before their condition 

 has become known to a European. This form is considered 

 very infectious : the natives shun the sick person, and will on no 

 account bury tho.se who die : they even remove from the neigh- 

 bourhood of the hut where the patient died. The natives have 

 a remedy for the disease, but never have it ready to hand when 

 required ; the missionaries, therefore, keep it prepared. This 

 remedy consists of a certain insect — a common native fly— many 

 of which are crushed and mixed with vinegar, the preparation 

 thus made being rubbed on the swelling. So great is the 

 terror of the natives when attacked by the disease, that the 

 missionaries' greatest fear is lest death should happen from 

 sheer fright. Buddu has for many years been the centre of this 

 plague in its worst form and Bishop Hanlon disputes the state- 

 ment made by Dr. Koch that the disease has travelled from 

 other parts of Uganda to Buddu, and thence south to German 

 territory, he being of opinion that the plague was introduced 

 into Uganda by way of the German East African territory, which 

 has been for many generations the chief Arab route to that part 

 of Africa. 



March 7. — Mr. J. Cosmo Melvill, President, in the chair. — 

 A new version of Argand's proof that every algebraic equation 

 has a root, by Prof. II. Lamb, F.R.S.— Prof. Schuster, F.R.S., 

 exhibited some lantern slides illustrating researches made by 

 Mr. G. llemsalech and himself on the velocity of metallic 

 molecules in the electric spark (see p. 350). 



Dublin. 

 Royal Dublin Society, February 22. — Prof. G. F. Fitz- 

 Gerald, F. R.S., in the chair. — Prof. T. Johnson gave an 

 account of the improvement of bog land, illustrating his remarks 

 by an account of the work carried on by Dr. Baumann at the 

 bog experimental station, Bernau, Bavaria, visited by him last 

 year.— Prof. W. F. Barrett read a paper on the remarkable 

 thermo-electric behaviour of certain alloys of nickel steel. In 

 the course of an examination of the physical properties of 

 numerous alloys of steel prepared by Mr. R. A. Hadfield, of 

 the Ilecla Steel Works, Sheffield, the author found the thermo- 

 electric behaviour of some of these alloys so remarkable as to be 

 worthy of a separate note. Two alloys of nickel and manganese 

 steel marked 1414 A and 1414 B, which had the enormous electric 

 resistances of 90-6 and 97-5 microhms per cubic cm. respec- 

 tively (see next paper), were found to give an almost constant 

 electro-motive force through a wide range of temperature, when 

 coupled with iron as the second metal. In the case of 1414 B 

 coupled with ll-.e purest commercial iron, the electromotive 

 force rose rapidly up to a temperature of 300' C, and then 

 remained practically constant up to Soo C, a range of 500° C, 

 that is, from a low black heat up to a bright red heat. Such a 

 couple would form a new standard of electro-motive force, as it 

 Ls easily made and simj ly requires heating in any gas flame. 

 Coupled with platinum nslead of iron these alloys give an 

 increasing electromotive force, from about 200° C. to a white 

 heat, the direction of the electro-motive lorce changing below 

 200 C. The second part of the paper deals with the curve of 

 electro-motive force on cooling ; which is found to be not co- 

 incident with that on heating in the case of iron and steel 

 Coupled with platinum. At corresponding temperatures a lower 

 electro-motive force is noticed in cooling than in heating, the 



NO. 1534. VOL. 59] 



difference being least marked with pure iron, and most, with 

 steel, the temperature ranging from o to 900 C. The heating 

 and cooling thermoelectric curves thus enclose an area which 

 represents the molecular work done on the iron and steel during 

 the cycle. This may be connected with the phenomena of 

 recalescence. In the case of a couple of 1414 B and platinum 

 the cooling curve, however, shows a higher electro-motive force 

 than the heating curve at corresponding temperatures. The 

 author is continuing his investigations on these and other points. 

 — A paper on the electric conductivity and magnetic perme- 

 ability of an extensive series of steel alloys (Part i.), by Prof. 

 W. F. Barrett and .Mr. W. Brown, was read by Prof. Barrett. 

 This paper gives the main results of four years' work on upwards 

 of a hundred different alloys of steel prepared by Mr. R. .\. Had- 

 field. For the purpose of investigation the alloys were prepared 

 in the form of rods 106 cms. long and about 05 cm. diameter. 

 The electric conductivity was determined by the potential 

 method, and referred to Matthiessen's standard of pure 

 copper as 100. Some of the alloys could not be 

 obtained in a homogeneous condition ; those which could 

 be were divided into three classes : (i) those with one 

 element added in varying proportions, of which there were 

 eight groups containing about fifty different alloys ; (2) those 

 with two elements added, of which there were fourteen groups, 

 also with fifty different alloys ; and (3) those with three or more 

 elements added, of which there were five groups with six 

 different alloys. The results were plotted in curves, and show 

 the strikingly different effect which the addition of different 

 elements have on the conductivity of iron. The alloys of 

 tungsten steel diminishing the conductivity least and those of alu- 

 minium and silicon most, manganese having almost as great 

 an effect as the two latter. In all cases the conductivity 

 rapidly falls with small additions of a foreign element up to 2 

 per cent, in some cases, and 7 to 10 per cent, in others, after 

 which larger additions of the foreign element have but a small 

 effect on the conductivity. In the case of eight different alloys 

 the material was obtained in the form of wire and strip, and 

 the specific resistance and temperature coefficient determined in 

 this condition. The highest resistance was obtained with a 

 nickel-manganese steel alloy marked 1414 B, which gave the 

 enormous resistance of 97"52 microhms per cubic cent, and the 

 remarkably low temperature coefficient of 0085 per cent, per 

 1° C. Another similar alloy, marked 1414.^, with somewhat 

 less nickel, had a specific resistance of 9062 microhms per 

 cubic cent, and a temperature coefficient of o 1046 per cent, per 

 i' C. ; another gave Sg microhms. These exceed rheostene, 

 also an alloy of nickel and manganese steel, which was found 

 by the authors in 1895 '° have a specific resistance of 83'I 

 microhms per cubic cent, and a temperature coefficient of 0'I09 

 per cent, per i' C. The second part of the paper deals with 

 the magnetic properties of these alloys. Permeability tests 

 were made, and complete H and B curves obtained for forty- 

 four different alloys. The results are given in the curves and 

 tables attached to the paper. A standard curve was obtained 

 of the purest commercial iron containing less than 003 per cent, 

 of carbon. In the case of the tungsten steels, the results are 

 extremely remarkable and of practical importance in the dis- 

 covery of the best alloy for the construction of permanent mag- 

 nets. The effect of nickel in the magnetic permeability is also 

 very striking : here, as in other cases, the thermal treatment 

 of the alloy after manufacture was a matter ol much conse- 

 quence. The rods were therefore all .submitted to the same 

 thermal treatment, and the permeability taken after annealing. 

 In addition, duplicate sets of many of the alloys were made in 

 the annealed, and unanncaled condition, and the electric conduc- 

 tivity and magnetic permeability with complete B and H curves 

 determined in both conditions. The annealing process consisted 

 in heating the rods to a temperature of 1000 C. in a large 

 annealing furnace, and then allowing them to cool very slowly 

 down to the temperature of the air. This took neatly 100 hours, 

 or upwards of four days and four nights. 



Edinbdrc.h. 

 Royal Society, February 20.— Prof Chrystal in the chair. 

 — Dr. Buchan, in a communication on the tidal currents of the 

 North Sea, drew attention to the facts which had been established 

 by experiments made by the Scottish Fishery Board. According 

 to Dr. Fulton's summary, the current of surface waters w.is down 

 the east coast of Scotland and England as far as Spurnhead, 

 then eastwards towards the north of Denmark, and finally 



