248 



NATURE 



[May 18, L916 



stage, and remarks that it can be followed among 

 British deposits from the beginning to the end. We 

 commend his work to the notice of those who are 

 interested in Palaeolithic man and the associated 

 mammals. 



The annual volume of "Records of the Survey in 

 India" (vol. vii.) for 1913-14 has recently been pub- 

 lished, and is a summary of an immense amount of 

 useful work carried out under the supervision of the 

 Surveyor-General of India, Sir S. G. Burrard. Apart 

 from the details of the trigonometrical and geodetic 

 operations, one of the most interesting chapters deals 

 with the exploration of the north-east frontier. This 

 work was done by Capts. Bailey and Morshead in 

 1913, and by the Abor exploration party in 191 1-12-13. 

 Up to that time almost the sole authority for the Abor 

 country was Kinthup, w-ho explored the course of the 

 Tsan-po through the Himalayan Range in 1880-83., 

 Kinthup, who was sold into slavery by his master, a 

 Chinese lama, had been widely discredited, but in this 

 report Capt. G. F. T. Oakes, in a critical discussion 

 of his work, proves its trustworthiness. 



The report on the state of ice in the Arctic Seas for 

 1915 has made its appearance {Dei Danske Meteoro- 

 logiske Institutj Kjobenhavn). There are charts for 

 April, May, June, July, and August, with full explana- 

 tions of the data gathered from all available sources. 

 The publication is printed in Danish and English in 

 parallel columns. Most interesting are the abnormal 

 ice conditions that prevailed in Spitsbergen waters. 

 As early as May there were symptoms of an unusually 

 bad season. In June the pack extended far to the 

 westward, and there was no approach to the fjords. 

 In July the belt of pack narrowed a little, but even in 

 August it was lying all along the west coast. More 

 remarkable still was the extension of this belt of pack, 

 throughout the summer, well to the north of Prince 

 Charles Foreland— an occurrence altogether excep- 

 tional. It is suggested by Commander Speerschneider, 

 the author of the report, that some of the Greenland 

 ice had drifted eastward to Spitsbergen waters, and 

 mixed with the ice that normally sweeps round South 

 Cape from the Barents Sea. Certainly in 1907 Green- 

 land pack reached to 8°" E. in the latitude of Ice 

 Fjord, Spitsbergen, which is within the limits of the 

 space covered last year by the pack under discussion. 

 This explanation would also account for the northward 

 extension of the ice. Off the north coast of Iceland 

 ice conditions were bad until the end of July, which is 

 again an abnormal state of affairs. 



A GOOD instance of the high appreciation by scien- 

 tific Americans of the circulars issued from time to 

 time by the Bureau of Standards at Washington is 

 provided by the recent issue by the Bureau of a third 

 edition of the circular on magnetic testing of mate- 

 rials. It covers fifty pages, and is issued at 15 cents 

 a copy by the Government Printing Office at Wash- 

 ington. It deals with the methods of measure- 

 ment in use at the Bureau, the results obtained with 

 typical commercial magnetic materials, and gives a 

 great deal of general information on magnetic sub- 

 jects. Induction and hysteresis data for straight bars 

 are obtained by the Burrows form of permeameter, in 

 which the bar under test is combined by means of two 

 soft iron yokes with an auxiliary bar to form the 

 magnetic circuit. Core loss determinations are made 

 according to the specifications of the American Society 

 for Testing Materials on strips 5 by 25 cm., cut half 

 along, half across, the direction of rolling. They are 

 assembled in four equal bundles, and with four corner 

 pieces constitute the magnetic circuit. The measure- 

 ments are made by means of the ballistic galvanometer 

 in each case. A number of hysteresis curves for 



NO. 2429, VOL. 97] 



typical materials and a table of magnetic susceptibili- 

 ties of chemical elements and compounds are g^ven. 



In two papers published in the Journal of the Society 

 of Chemical Industry (vol. xxxv.. No. 4) Mr. G. S. 

 Robertson discusses the question of the availability 

 of the phosphates in basic slags and mineral phos- 

 phates. The increasing demand for phosphatic fer- 

 tilisers is leading to a search for substances previously 

 considered of little value for this purpose. The value 

 of 2 per cent, citric acid as a solvent for testing the 

 availability of phosphates has been challenged for 

 minerals and fluorspar slags. On. account of the low 

 solubility of these phospbatic materials in this solvent 

 it has often been assumed that they are not sio valu- 

 able as the high-grade basic slags ; indeed, Wagner 

 introduced this test to detect the adulteration of basic 

 slag with rock phosphate. Mr. Robertson shows 

 that a sufficient number of extractions dissolve out 

 quite as much phosphoric acid from the minerals as 

 from the slags. The fineness of grinding is also an 

 important factor in the solubility of rock phosphates. 

 Field results at various English centres and in the 

 United States have shown the high value of rock 

 phosphates, and the author concludes that the citric 

 test is worthless as a measure of the relative values of 

 phosphatic fertilisers. 



It has usually been assumed that the wear of coins 

 in circulation is due entirely to abrasion. In a 

 memorandum by Sir T. K. Rose, however, contributed 

 to the forty-fifth annual report of the Deputy-Master 

 of the Mint, attention is directed to the effect of 

 grease, derived from the sw^eat of the fingers or from 

 other sources, in accelerating the wear of coins. The 

 fatty acids of the grease have a corrosive action upon 

 the metal. Copper, in particular, even if present only 

 in small quantity alloyed with gold or silver, is con- 

 verted into an oleate, stearate, or other salt. Haagen 

 Smit, of the Utrecht Mint, found by analysis that the 

 dirt on a bronze coin contained 36 per cent, of copper 

 in the form of pulverulent compounds of the fatty 

 acids. When the coin is handled the dirt is in part 

 detached, and the coin undergoes a rapid Toss of 

 weight. Gold or silver is not readily converted into 

 salts, but the removal of the alloying copper leaves 

 the less easily attacked metals in a spongy form which 

 offers little resistance to abrasion. A surface layer of 

 pure silver at first preserves coins from chemical 

 attack, but this layer is soon removed by mechanical • 

 wear. In new coins the rapid loss of weight which 

 occurs is doubtless due at first to abrasion, but when 

 the rough edges have been removed chemical action 

 mav prove to be of the first importance in the succeed- 

 ing deterioration. 



In vol. XV. (part i.) of the Transactions of the Eng- J 

 lish Ceramic Society the feature of most scientific in- « 

 terest is a series of three "Studies on Flint and 

 Quartz," by Dr. J. W. Mellor and two collaborators. 

 The first paper describes the effects upon quartz and 

 flint of heating these substances at temperatures 

 obtained in pottery ovens. It has long been known 1 

 that quartz on calcination or fusion shows a notable | 

 decrease in specific gravity — a change which is pre- 

 sumably attributable to the conversion of the quartz 

 molecule to a lower degree of polymerisation. Flipt, 

 it is found, undergoes similarly an alteration of specific 

 gravity when calcined, but much more rapidly than 

 quartz. Between grey flint and black flint there^ is 

 likewise a difference in the rapidity of transformation 

 to the form of lower density, grey flint being changed 

 somewhat more quickly than the black variety. The 

 practical bearing on certain ceramic operations of these 

 differences of behaviour Is pointed out. In the second 



