4i8 



NATURE 



[September i, 1892 



prescribe a different course, viz., to retain as authority for a 

 species the name of the original describer, and that is the course 

 adopted in, I think, most of the Challenger reports, and by 

 very many zoologists. I may state briefly as an example the 

 first case that occurs to me — I have no systematic books here to 

 refer to. (l) About 1870 Cunningham described a new 

 Ascidian as Cynthia gigantea. (2) About 1880 Herdman trans- 

 ferred that species to the genus Molgula. (3) In the Challenger 

 report this species figures as Molgtila gigantea , Qyxxvava^zxa. ; 

 and I would submit that that, rather than the course indicated 

 in the review, is "under the generally accepted rules of nomen- 

 clature." W. A. Herdman. 

 Tarbert, Loch Fyne, August 23. 



An Earthquake Investigation Committee. 



It may perhaps interest you and your readers to hear that by 

 the Imperial ordinance of June 25 a committee has been estab- 

 lished for the investigation of the earthquake phenomena, with 

 the view of finding methods of predicting earthquakes, if pos- 

 sible.and of ascertaining the nature of construction, building, and 

 Otherwise, best calculated to resist the effect of the shocks. Pre- 

 sident Kato, of the Imperial University, has been nominated 

 the president, and myself the secretary. Other members of the 

 Committee are Furnichi (Director and Professor of Civil En- 

 gineering, Engineering College, and Head of the Engineering 

 Bureau of the Department of the Interior), Tatonno (Professor 

 of Architecture, Engineering College), Tanabe( Professor of Civil 

 Engineering, Engineering College), Tanakadate (F.R. S.E., 

 and Professor of Physics, Science College), and Nagaol>a (As- 

 sistant Professor of Physics, Science College), Koto (Professor 

 of Geology, Science College), and Kochibe (of the Geological 

 Survey), Sekiya and Omori (Seismologists), Nakamura (of the 

 Meteorological Bureau), and a foreign member. Prof. J. Milne 

 Other members will be nominated by and by. The Parliament 

 has granted 42,000 yen for this year, chiefly for the purchase of 

 various instruments. The committee will be glad to receive 

 any communication or lluggestion on the subject. Address : 

 Earthquake Investigation Committee, care of the Department 

 of Education, Japan. D. KiKUCHl. 



Imperial University, Tokyo, July 21. 



Prehistoric Epochs. 



I DO not think that the English authors who have written on 

 prehistoric times have divided the Pleistocene in epochs, as Prof. 

 G. de Mortillet has done in France. Would it be possible to 

 use in England subdivisions similar, or almost similar, to 

 those used in France, and almost generally adopted, although 

 that classification is often subject to criticism ? 



According to Prof. G. de Mortillet, Palaeolithic silexhave been 

 found in England that could be respectively related (i) to the 

 type of Chelles or Chelleen (Hoxne, Biddenham) ; (2) to the 

 type of the Moustier or Mousterien (Creswell, High Lodge) ; 

 (3) to the type of Solutre or Solutreen (Creswell) ; (4) and to 

 the type of La Madeleine or Magdalenien (Creswell, Kent's 

 Hole). The same author says that at Creswell (Derbyshire) 

 Palaeolithic silex belonging to the Mousterien, Solutreen, and 

 Magdalenien divisions have been found in situ, superposed as in 

 the French stations, and according to him his classification 

 could be adopted for the English prehistoric stations. Is that 

 the opinion of the English authors who have most recently 

 written on the matter, and is it possible to make a classification 

 founded on the objects of the human prehistoric industry, 

 parallel to the palseonto logical and stratigraphical classifications ? 



Edmond Bordage. 



Museum d'Histoire Naturelle de Paris, August 2. 



At Portrush, 



Being on holiday (at Portrush) in the second week of 

 August, I discovered growing on the sand dunes there the 

 following species, bearing beautiful pure white blossoms. I 

 found several patches of each : — 



Thymus Serpyllum (wild thyme) ; Prunella vulgaris (self- 

 heal) ; Gentiana campestris (field gentian) ; Erica Tetralix 

 (cross-leaved heath). 



Also the wild strawberry, bearing abundantly white fruit. 

 Are these cases of reversion or of adaptability ? Moths were very 

 plentiful all over the dunes. James Rigg. 



18, Wilton Drive, Glasgow, Aug. 18. 



NO. II 92, VOL. 46] 



Origin of Idea that Snakes Sting. 



Will you kindly inform me as to the origin of the idea that 

 snakes sting? Froude, in "The English in Ireland," page 

 356, vol. i., writes: "The clergy started as if stung by a 

 snake." Archdeacon Farrar, in "Darkness and Dawn," uses 

 the metaphor of snakes stinging. Sir T, Browne ("Vulgar 

 Errors") says "That snakes and vipers sting," &c., &c., "i-: 

 not easily to be justified. It is not fair to bring in Shakespeare 

 as to a matter of natural history. Cyril Frampton. 



July 29. 



ON THE RELATIVE CONTAMINATION OF 

 THE WATER-SURFACE BY EQUAL QUAN- 

 TITIES OF DIFFERENT SUBSTANCES. 

 THE experiments of Lord Rayleigh and Prof. Roentgen 

 on the thickness of the invisible films of oil on 

 contaminated water- surfaces, led me to repeat these 

 measurements by a somewhat different method, which 

 may perhaps be worth describing, and at the same 

 time to compare the contaminating effect of various 

 substances. 



In order to divide very small masses exactly I chose 

 the course of Lord Rayleigh ' of transferring the con- 

 taminating substance to the water-surface by means of a 

 volatile solvent. But instead of ether I used benzine, and 

 let the drops of the solution evaporate directly from the 

 water instead of vaporizing them on a metal plate and 

 then immersing this, as Lord Rayleigh did. 



As a fixed condition of the water-surface Lord Rayleigh 

 chose the tension when the movements of camphor frag- 

 ments are stopped. Still more suitable for my purpose, 

 however, I found another smaller degree of contamination, 

 which is always to be fixed with great exactness. I mean 

 that degree at which the tension just begins to sink. As I 

 have already explained (Nature, vol. xliii. No. 11 15, 

 p. 437) the sinking of tension does not begin gradually 

 from the very commencement of contamination, but 

 abruptly, when the latter has arrived at a certain value, 

 and then the falling of tension takes place very rapidly. 

 The state of constant tension I have called the normal 

 and that of variable tension the anomalous condition. 



My task was therefore to examine how much of a sub- 

 stance is required to make a surface of a given size enter 

 the anomalous state or to find the area of a surface 

 made anomalous by a given mass of the substance. The 

 latter method was generally preferred, for it was more 

 convenient to me. 



The observations were made with the adjustable trough 

 and balance 2 described in Nature, March 12, 1891, 

 p. 437, and were as follows : — 



Of the substance to be tried 13 mg. were dissolved in 

 300 ccm. of benzol. Then the trough being filled with 

 water and the surface made as clean as possible by sliding 

 the partition all over the length of it several times, the solu- 

 tion was transferred to the surface in drops, each of which 

 had a volume of 31 cmm. or about 1/9600 of the whole 

 solution and thus contained 0-00x354 mg. Four drops 

 were introduced each time in order to equalize accidental 

 irregularities of size. When the evaporation of the 

 benzol was finished I diminished the length of the sur- 

 face till it became anomalous, and this length was noted. 

 Then immediately other four drops were introduced, 

 again measured, and so on. After two or more observa- 

 tions the surface was cleaned anew, but generally the first 

 length was observed to be a little too large on account of 

 the imperfect purity of the surface.- 



A sufficient number of observations having been thus 

 made, the original contamination of four drops of the 



' Proc. of the Royal Society, 1890, vol. xlviii., No. 293, p. 127. 



^ For the purpose of actual measurements of surface-tension, I have con- 

 structed another instrument of larger dimensions ; but to indicate only a 

 slight variation of tension, any sensible balance with an adhering disc or 

 wire-ring of any shape and size may be employed. 



