No. 1070, Vol. 42] 



NATURE 



n 



\\. Saunders, on the tongue of the British Hymenoptera Antho- 

 ])hila, in the absence of the author was read by Mr. W. Percy 

 Sladen, and was illustrated by excellent drawings. 



Physical Society, April i8. — Prof. W. E, Ayrton, 

 F.R.S., President, in the chair. — Prof. Kiicker described 

 the results of some recent magnetic work undertaken by 

 himself and Prof. Thorpe in connection with their mag- 

 netic survey of the United Kingdom. — Mr. T. H. Blakesley 

 (Hon. Secretary) read a paper, on a theory of permanent 

 magnetism, by M. Osmond. The author stated that iron exists 

 in two distinct physical states, one soft, or "a iron" and the 

 other hard, or " /8 iron." The jS variety k non-magnetic, and is 

 formed during heating, hardening, or by electrolysis, whilst the 

 soft or a modification is produced by long annealing. In a piece of 

 steel the author considers the j8 molecules to form a rigid frame- 

 work in which the a molecules become interlocked under the 

 influence of magnetizing force, and on the degree of interlocking 

 the permanent magnetism depends. By a graphical method it 

 is shown that the permanent magnetism should be a maximum 

 when the two varieties are present in equal quantities. If the 

 proportions of carbon and manganese in the steel are consider- 

 able, then nearly ail the iron is of the /3 variety, and the steel is 

 nearly non-magnetic. In hardening a piece of ordinary steel, the 

 surface layers being cooled most rapidly contain more )8 molecules 

 than the interior ; hence for a certain degree of hardness (when 

 the outer layers have more o molecules than 3 ones) a laminated 

 magnet v.ill be a better permanent magnet than a solid one, but 

 for a much greater degree of hardness the reverse may be the 

 case. Mr. Swinburne asked if the theory would account for the 

 increase of induction which occurs when the circuit of a per- 

 manent magnet is closed ; most theories founded on the orienta- 

 tion of particles by the magnetizing force seemed defective in this 

 respect. Some time ago he had suggested that the permeability 

 of iron should be tested by first magnetizing it one way, and then 

 at right angles to the first direction ; recently he had been in- 

 formed that no increase of permeability was observed when the 

 experiment was performed. Prof. Perry said he had subjected 

 iron to magnetization in one direction and found the permea- 

 bility for small forces in a direction at right angles much smaller 

 than he had anticipated ; the first magnetizing force was kept 

 constant when the small perpendicular one was applied. Mr. 

 Swinburne thought that -for such small perpendicular forces the 

 permeability should be nearly infinite. He also said there 

 seeme'd to be a sort of angular hysteresis in iron, for if a loose 

 running armature was turned slowly round by hand, it would 

 come back 2° or 3° when left free. The President re- 

 marked that, as far as he could see, M. Osmond's theory does 

 not account for the great influence which a small percentage 

 of tungsten has on the magnetic property of steel, and all 

 theories which failed in this particular must necessarily be im- 

 perfect. Mr. Blakesley pointed out that the ordinary hysteresis 

 curves showed that a small superimposed magnetizing force in 

 a direction different from the primary one produced only a 

 small change in the induction, and hence would give a small 



permeability. For example, the increment HH' (see diagram) 

 causes an inciease RP in the induction, whilst an equal decrement 

 H'H produces only a change PS. 



Geological Society, April 16.— J. W. Hulke, F.R.S., 

 Vice-President, in the chair. — The following communications 

 were read :— On the disturbed rocks of North- Western Germany, 

 by Prof. A. von Konen, For.Corr.G.S.— On the origin of the 

 basins of the Great Lakes of America, by Prof. J. W. 

 Spencer, State Geologist -of Georgia. From the study of the 

 hydrography of the American lakes, from the discovery of buried 

 channels revealed by borings, from the inspection of the glacia- 

 tion of the lake region, the consideration of the late high con- 

 tinental elevation, and the investigation of the deformation of 

 old water-levels, as recorded in the high-level beaches, the ex- 

 planation of the origin of the basins of the Great Lakes becomes 

 possible. The original Erie valley drained into the extreme 

 western end of Lake Ontario— the Niagara river being modern- 



— by a channel row partly buried beneath drift. Lake Huron, 

 by way of Georgian Bay, was a valley continuous with that of 

 Lake Ontario ; but between these two bodies of water, for a 

 distance of about 95 miles, it is now buried beneath hundreds 

 of feet of drift. The old channel of this buried valley entered 

 the Ontario basin about twenty miles east of Toronto. The 

 northern part of Lake Michigan basin was drained into the Huron 

 basin, as at present ; whilst the southern basin of that lake 

 emptied by a now deeply drift-filled channel into the south- 

 western part of Huron. The buried fragments of a great 

 ancient valley and river, and its tributaries, are connected with 

 submerged channels in Lake Huron and Lake Ontario, thus 

 forming the course of the ancient St. Lawrence (Laurentian) 

 river, with a great tributary from the Erie basin and another 

 across the southern part of the State of Michigan. This valley 

 is of high antiquity, and was formed during times of high con- 

 tinental elevation, culminating not long liefore the Pleistocene 

 period. The glaciation of the region is nowhere parallel with 

 the escarpments, forming the sides of, or crossing the lakes or 

 less prominent features. During the Pleistocene period, and 

 especially at the close of the episode of the upper Till, the 

 continent w as greatly depressed, and extensive beaches and shore- 

 lines were made, which are now preserved at high elevations. 

 With the re-elevation of the continent these old water-levels have 

 been deformed, owing to their unequal elevations. This de- 

 formation is sufficient to account for the rocky barriers at the 

 outlets of the lakes. Some of the lakes have been formed, in 

 part, by drift obstructing the old valley. The origin of the 

 basins of the Great Lakes may be stated as the valley (of erosion) 

 of the ancient St. Lawrence river and its tributaries, obstructed 

 during and particularly at the close of the Pleistocene period, by 

 i terrestrial movements, warping the earth's crust into barriers, thus 

 producing lake-basins, some of which had just been formed in 

 1 part by drift deposited in the ancient valley. The reading of 

 I this paper was followed by a discussion, in which Dr. Hrnde, 

 I Prof. Bonney, Dr. Irving, Mr. Clement Reid, Rev. E. Hill, 

 j Prof. Seeley, Mr. Whitaker, and the author took part. — On 

 Ornithosaurian remains from the Oxford Clay of North- 

 ampton, by R. Lydekker. — Notes on a " wash-cut " found in 

 the Pleasley and Teversall Collieries, Derbyshire and Notting- 

 hamshire, by J. C. B. Hendy. 



Chemical Society, March 20.— Dr. W. J. Russell, F.R.S., 

 President, in the chair. — Prof. J. W. Judd, F. R.S., delivered a 

 lecture on the evidence afforded by petrographical research of 

 the occurrence of chemical change under great pressure, in which 

 he discussed the question as to how far the phenomena observed 

 by the geologist in the study of rocks under the microscope can 

 be explained by the laws that have been experimentally de- 

 termined by the physicist and chemist, — The following papers 

 were read : — The formation of triazine-derivatives, by Prof. R. 

 Meldola, F. R.S. — Contributions to the knowledge of mucic acid ; 

 Part I, hydromuconic acid, by Dr. S. Ruhemann and Mr. F. F. 

 Blackman. — The molecular weights of metals when in solution, 

 by Messrs. C. T. Heycock and F. H. Neville. The authors 

 give the results of their observations on the effect of various 

 proportions of silver, gold, copper, nickel, sodium, palladium, 

 magnesium, zinc, lead, cadmium, mercury, bismuth, calcium, 

 indium, aluminium, and antimony on the solidifying point of 

 tin. Of all these metals, antimony alone behaves abnormally, 

 producing a rise instead of a depression in the solidifying point. 

 In the majority of cases the atomic depression is a number not 

 far removed from 3, the theoretical value calculated from Van't 

 Hoffs formula. Assuming the truth of Raoult's generalization, 

 that the depression produced by a molecular proportion of any 

 substance in the solidifying point of the same solvent is the same 

 whatever the substance, it would therefore seem probable that 

 the molecules of most metals are of the same type, M„, where « 

 is the number of atoms in the molecule ; and if it be supposed 

 that the molecules of zinc, for example, when dissolved in tin 

 are monatomic as in the gaseous state, it would follow that n is 

 unity in the case of many other metals. In the case of alumin- 

 ium, the atomic depression is so nearly half the average value 

 that it seems probable that the molecule is diatomic. Indium 

 resembles alun inium in pniducing an abnormally low depression, 

 and it is noteworthy that the value for mercury is also distinctly 

 low, 



March 27. — Annual General Meeting for the election of 

 Officers and Council. — Dr. \V. J. Russell, F.R.S., President, in 

 the chair. — The President, in his address, discussed the teaching 

 of chemistry to medical students, and drew attention to the 



