May 12, 1921] 



NATURE 



341 



The death occurred in January this year, at 

 seventy-five years of age, of Dr. Jules Harmand, 

 -who was Avell known for his extensive explorations 

 in French Indo-China. In 1873 Dr. Harmand 

 took part in the investigations of the ruins of 

 Angkor, in Cambodia. His explorations in subse- 

 quent years embraced the basin of the Tonle Sap 

 and the lake of that name, as well as the country 

 between there and Bassac, on the Mekong. In 

 1877 Dr. Harmand explored the Boloveu plateau 

 in Laos, and succeeded in crossing the moun- 

 tainous country to Hue, in Annam. These explora- 

 tions shed much light on the interior of Indo- 

 China, and gained for Dr. Harmand in 1878 the 

 gold medal of the Paris Geographical Society. 



Later he entered the diplomatic service and was 

 for many years French ambassador at Tokio. 

 Dr. Harmand was the author of " Domination et 

 Colonisation," published in 1910, and he prepared 

 a French edition of Sir John Strachey's " India " 

 in 1892. 



We learn with regret from Science of April 22 

 that the death occurred on April 14 of Dr. Henry 

 Platt Cushing, who was for twenty-six years pro- 

 fessor of geology in Western Reserve University, 

 Cleveland, Ohio, and for about the same time 

 geologist in the Adirondack region for the Geo- 

 logical Survey of New York. 



Notes. 



" Cultured " pearls, recently introduced by a 

 Japanese firm, appear to have caused some alarm in 

 the gem trade. It has long been known that pearls 

 are the result of local irritation in the pearl-oyster 

 ■or pearl-mussel, caused by the introduction of some 

 foreign matter — usually the larva of a parasitic 

 organism which spends another part of its life-cycle 

 in an animal that feeds on the mollusc. The mollusc 

 retaliates by coating the unbidden guest with a smooth 

 layer of nacre (identical with the mother-of-pearl layer 

 of its shell, and consisting mainly of the orthorhombic 

 crystalline modification of calcium carbonate corre- 

 sponding with the mineral aragonite) ; and the result- 

 ing;- pearl is the elegant tomb of the objectionable 

 parasite. The Chinese have for centuries produced 

 this result artificially by inserting objects between the 

 shell and mantle of the fresh-water mussel, and 

 figures of Buddha on the inner surface of such shells 

 are common. The difficulty hitherto has been to cause 

 the formation of a spherical secretion unattached to 

 the shell of the mollusc. This now appears to have 

 been achieved by Mr. Mikimoto as a result of experi- 

 ments extending over forty years. It is said that 

 fragments of mother-of-pearl are inserted in the tissues 

 of the molluscs, which are then returned to the sea 

 for a period of several years. Another obvious method 

 would be to infect the oyster-bed with the appropriate 

 parasite. But, whether the foreign matter is intro- 

 duced accidentally or intentionally, the result pro- 

 duced by the oyster must be the same. The qualifica- 

 tion "artificial " would here apply rather to the pre- 

 tence that the products are essentially different. At- 

 tempts on the part of the trade to discredit what is 

 apparently an interesting scientific discovery are clearly 

 made only with the view of keeping up inflated prices. 

 The same selfish fight was made some years ago 

 against the artificially formed rubies and sapphires 

 (miscalled "synthetic," "reconstructed," and even 

 "imitadon"), which can be produced much more 

 economically than the naturally formed stones. Straw- 

 berries raised in pots under glass are sold without 

 question as strawberries— but wisely at a higher 

 price. Pearls are high in price because of their rarity, 

 but if they were plentiful and the more brightly 

 NO. 2689, VOL- 107] 



coloured mother-of-pearl were rare the cry would be 

 very different. 



The Kelvin gold medal for engineering was founded 

 in 19 14, principally by British and American engineers, 

 to commemorate the achievements of Lord Kelvin in 

 those branches of science which apply specially to 

 engineering. The award is made by a committee of 

 the presidents of the representative British engineer- 

 ing institutions, and recommendations are received 

 and considered from similar bodies in all parts of the 

 world. The first recipient was Dr. William Caw- 

 thorne Unwin, and the presentation was made by 

 Mr. A. J. Balfour in the hall of the Institution of 

 Civil Engineers on Wednesday, May 4. In the course 

 of his address Mr. Balfour said that Lord Kelvin 

 combined in a manner which had scarcely been 

 equalled before, except perhaps by Archimedes, the 

 power of theorising on the darkest and most obscure 

 secrets of Nature, and at the same time of carrying 

 out efficiently and practically some engineering feat. It 

 was therefore fitting that we should remember Kelvin 

 as one of the leaders in the movement which com- 

 pelled all modern engineers worthy of the name to be 

 not only men of practice, but also of theory. Dr. 

 Unwin 's name was honoured wherever engineering 

 was studied in English-speaking lands, and he had 

 imprinted his own seal upon the whole course of 

 study which young engineers had now to pursue. In 

 his reply Dr. Unwin congratulated the young en- 

 gineers of to-day upon their advantages in the pos- 

 session of well-organised colleges and on the recogni- 

 tion by all universities, even Oxford and Cambridge, 

 of a faculty of engineering. 



We are very glad that a reasonable agreement has 

 been arrived at between supporters and opponents of 

 the Plumage (Prohibition) Bill, with the result that 

 the Bill passed through Standing Committee D of the 

 House of Commons on May 10. It has often been 

 suggested that an advisory committee should be set 

 up to prepare a schedule of birds the plumage of 

 which might be imported, but this has been objected 

 to by promoters of prohibitive measures. The agree- 

 ment now arrived at includes the following terms : — 



