6o2 



NATURE 



[October 20, i8q2 



the various washing machines, and every process separating the 

 diamond from the matrix, in which exists a percentage of i 

 carat 205 milligrams in a load of 1600 pounds. There will be 

 a case containing over 10,000 carats of diamonds of all colours 

 and of the various qualities, with a full series of the associated 

 minerals and rocks. Every stage of the cutting and polishing 

 of the diamond will be represented. 



Nearly every mineral dealer in the United States has applied 

 for space, and from the foreign trips and other preparations it 

 is very evident that in the line of cabinet specimens and edu- 

 cational minerals the assembled collections will exceed those of 

 any other exposition in importance. 



One of the large gallery halls will contain a reference library 

 for the use of visitors. This it is hoped will be a very compre- 

 hensive exposition of the literature of the subject of mines, 

 mining, geology, and mineralogy. This is to be supplemented 

 by historical portraits, documents, and other allied material. 



An early history of mining and mining processes will be 

 shown, starting with stone hammers and other aboriginal imple- 

 ments found in the copper mines of Lake Superior and the tur- 

 quoise mines of New Mexico, the old Mexican Pateo, to the 

 most improved modern methods, and the remarkable sectional 

 and glass models of mines, prepared by eminent mining en- 

 gineers, used in the great mining lawsuits to prove their argu- 

 ments. 



One of the large corridor rooms in the gallery has been 

 offered to the American Institute of Mining Engineers for their 

 own use as a headquarters during the Exposition. They in turn 

 may extend the courtesy to mechanical and civil engineers, as well 

 as the English, German, French, and other foreign engineers 

 whose hospitality they enjoyed in 1889. There is every reason 

 to believe that at least from 800 to looo foreign engineers will 

 visit the Exposition. 



If only three-fourths of the promised exhibits are received, 

 and there is every assurance that there will be many more 

 coming, it may be safely said, even now, that the mining, 

 metallurgical, geological, and mineralogical exhibits of the 

 Columbian World's Fair will exceed in scientific importance 

 and in extent the combined exhibits of the Centennial, the 1878, 

 1889, the Paris and the Vienna Expositions, at least two-fold. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Cambridge.— Lord Walsingham, the High Steward of the 

 University, has expressed bis wish to give annually for three 

 years a gold medal for the best monograph or essay giving 

 evidence of original research in any subject coming under the 

 cognizance of the Special Board for Biology and Geology. The 

 offer having been accepted and the regulations for the medal 

 having been approved, the Special Board for Biology and 

 Geology give notice that the medal is offered for competition for 

 the second time during the ensuing academical year. The 

 essays are to be sent to the chairman of the Special Board (Prof. 

 Newton, Magdalene College) not later than October i, 1893. 



The regulations fcr the medal are published in the Cambridge 

 University Reporter, No. 908 (November 17, 1891), p. 186. 



Sir K. S. Ball, Loundean Professor, will give his inaugural 

 lecture in the Anatomical Theatre on Friday, October 21, at 

 noon. 



Dr. Cayley, Sadlerian Professor of Mathematics, resigns his 

 place on the Council of the Senate on October 25. 



The Council of the Senate recommend that the University of 

 the Cape of Good Hope should be affiliated to Cambridge, on 

 the same terms as those granted to New Zealand. 



London. — Four lectures upon "The Sun in its Relation to 

 the Universe of Stars " will be delivered in Gresham College, at 

 six p.m. on the evenings of October 25, 26, 27, and 28, 1892, 

 by the Rev. Edmund Ledger. 



SCIENTIFIC SERIALS. 

 The Journal of the Royal Agricultural Society of England, 

 3rd Series, Vol. iii., pt. 3. — Allotments and Small Holdings, 

 by Sir J. B. Lawes and Dr. Gilbert. The authors have col- 

 lected statistics relating to Allotments and Small Holdings in 

 Great Britain. They point out that "within the present cen- 

 tury there has been a great reduction in the number both of 



owners and of occupiers of farms not exceeding 50 acres in area, 

 such as it seems to be the object of the promoters of the Small 

 Holdings Act of 1892 greatly to increase." After noticing the 

 Rothamstead Allotments they proceed to discuss the conditions 

 essential to the success of small holdings, and they conclude 

 that ordinary rotation farming is much less suitable for small 

 holdings than dairy farming, the production of poultry and eggs, 

 and market gardening when favourable conditions exist ; the 

 authors do not believe, however, that the system of small hold- 

 ings will materially check the influx of agricultural labourers 

 into the towns. This number of the yournal also contains a 

 short article by W. H. Hall on Small Holdings in France. 

 Mr. Hall is "convinced that small holders (in England) have 

 a great future before them as soon as they can be educated up 

 to producing such articles as require to be consumed fresh, and 

 will not bear long carriage." This last clause contains the key 

 of the whole matter. — On the Vermin of the Farm, pt, ii., by 

 J. E. Harting. In this paper the author has much to say in de- 

 fence of the mole {talpa europaa), and of the weasel [mtistela 

 vulgaris) ; there is little but condemnation, however, for the 

 hedgehog, the stoat, and the polecat ; the last-mentioned ani- 

 mal is now hardly known to most people, though the domesti- 

 cated variety (the ferret) is common. — The Warwick Meeting 

 of 1892, by Dr. Fream, Official Reporter. This report shows 

 the meeting to have been a good average one, except in the 

 attendance of visitors on the last two days. Judge's reports 

 show that in many cases the quality of the exhibits of live stock 

 was far above the average. — Miscellaneous Implements Exhi- 

 bited at Warwick, by T. H. Thursfield.— The Farm Prize 

 Competition of 1892, by J. B. Ellis.— Among the shorter 

 articles is one deserving of careful attention, entitled New 

 Modes of Disposing of Fruit and Vegetables, by Chas. White- 

 head, in which are discussed the "evaporating" and the "can- 

 ning " of fruit ; methods already in use in Queensland are de- 

 scribed and discussed with reference to their adoption in this 

 country when prices for fresh fruit are low. — Dr. J. W. Leather 

 contributes a short article upon his method of detecting and esti- 

 mating " castor-oil seeds in cattle foods. " A weighed quantity 

 of the suspected food is digested with hot dilute sulphuric acid 

 (or HCl, about 2 p.c.) for half an hour, washed free from acid, 

 re-digested with a hot dilute solution of caustic soda, washed, and 

 then finally treated with a quantity of bleaching powder. The 

 husks of all seeds other than castor-oil seeds are bleached by 

 this treatment, and any unbleached husks can be picked out and 

 weighed. 



Wiedeman's Annalen der Physik und Chemie, No. 9. — The 

 principle of least effect in electrodynamics, by H. von Helmholtz. 

 — On the differences of potential of chains with dry solid electro- 

 lytes, by W. Negbaur.— On the reciprocity of electric osmose 

 and flow currents, by U. Saxen. — Resonance phenomena and 

 absorptive capacities of metals for the energy of electric waves, 

 by V. Bjerknes.— Objective presentation of the Hertzian experi- 

 ments with rays of electric force, by L. Zehnder. — Dispersion 

 and absorption of light according to the electrical theory of light, 

 by D. A. Goldhammer. — On the measurement of high temper- 

 atures, by L. Holborn and W. Wien. The apparatus was a 

 modification of Le Chatelier's thermo-element, consisting of a 

 combination of platinum and a platinum-rhodium alloy. This 

 was calibrated by placing it inside the porcelain vessel of an air- 

 thermometer and compairing the readings, different thermo-cou- 

 ples were compared by exposing together in short porcelain tubes, 

 two branches being welded together. The following fusing 

 temperatures were deduced : gold 1072^, silver 968^ copper 

 1082°. — On the expansion of gases at low pressures, by G. Me- 

 lander. Working with pressures ranging from 770 to 4mm, 

 and temperatures from 0° to 100°, the gases being kept at constant 

 volume, the supposed law of constant decrease of coefficient of 

 expansion with decreasing pressure was found not to hold good. 

 That of air decreases down to 232mm, where it is 0-003659, 

 and then increases. That of carbon dioxide decreases down to 

 76mm, after which it increases, whilst that of hydrogen increases 

 steadily. — Specific gravity and heat of fusion of ice, by J. v. 

 Zakrzevski. The apparatus was a very delicate form of Bunsen's 

 ice calorimeter. The specific gravity of ice at- 0701^0. was 

 found to be 0"9i67io. The cubical coefficient of expansion at 

 that temperature was 0-000077, which gives for the sp. gr. of ice 

 at o^ C the value 0-916660.^ — On the theoretical conceptions of 

 Georg Simon Ohm, by K. Von der Miihll.— Variation of the 

 specific volume of sulphur with the temperature, by M. Toepler. 



NO. I 199, VOL. 46] 



