August 7, 1885.] 



SCIENCE. 



117 



cliance; but, if they have an automatic motion, they 

 are in a degree independent of the air-current, and 

 can direct their own course. The amoeboid move- 

 ments of the cells may have some connection with 

 the presence of an excess of nutrient matters for 

 distribution. 



— Herr Hilt of the Prussian fire-damp commission 

 says, as the outcome of a long series of practical ex- 

 periments on the very fine coal-dust of Pluto mine 

 in Westphalia, that " there can be no doubt, that, with 

 this kind of dust, the flame could be lengthened out 

 to any desired length, provided the gallery and layer 

 of dust on its floor were made equally long." Differ- 

 ences in chemical composition do not appear to have 

 so much effect in controlling the length of flame pro- 

 duced by a given dust as the comparative fineness of 

 the particles. The French commission finally pro- 

 nounced that coal-dust is an element of very second- 

 ary importance; but the Prussian commission, partly 

 from the large scale upon which it worked, and 

 partly from the natural fineness of the dust upon 

 which it experimented, has arrived at the opposite 

 conclusion. One of the most violent explosions on 

 record recently occurred in the Camphausen colliery; 

 and it is generally admitted that coal-dust, not fire- 

 damp, was the principal cause of destruction. 



— It is generally admitted that the most effective 

 arrangement of a course of instruction in qualitative 

 analy&is includes a brief study of the more important 

 compounds of the elements composing the group, as 

 regards their solubility, followed by a method of analy- 

 sis, this plan being applicable both to basic and acid 

 analysis. The acids may be classified with nearly the 

 same precision as the bases, so that the presence or 

 absence of a group containing half a dozen acids can 

 be shown by means of a single reagent. The ' Trea- 

 tise on practical chemistry and qualitative inorganic 

 analysis,' by Frank Clowes (Philadelphia, Lea broth- 

 ers & Co., 1885), follows the above plan in gen- 

 eral, except in the arrangement of the acids. It 

 adheres to the use of tables, which may be regarded 

 of questionable utility unless the student is required 

 to prepare them for himself. The selection of relia- 

 ble tests and methods is, for the most part, all that 

 could be desired. Much useful information is given 

 concerning laboratory arrangements, apparatus, prep- 

 aration-work, and chemical operations in general, 

 which will doubtless be serviceable to many teachers, 

 especially the hints on laboratory construction, and 

 the directions for preparing reagents and substances 

 for analysis. In fact, from its scope and general ar- 

 rangement, the work seems better adapted for the 

 use of teachers and advanced students than for an 

 introductory text-book on qualitative analysis. 



— In Symon^s meteorological magazine (April, 

 1885) the old idea of having a floating mid-Atlantic 

 meteorological observatory is once more urged. As 

 most of the changes in British weather are due to 

 the passage of storms from the west to the east, the 

 only practicable way of forecasting these storms is by 

 some such station, in about latitude 50° north, and 

 longitude 20° west. The depth of the water at this 



point is about two thousand fathoms (two miles and a 

 quarter) ; and a mooring-chaiu of that length would 

 be a decided novelty, but not an impossibility, for the 

 cable-laying steamship Faraday once found herself 

 in the course of a cyclone which passed by without 

 causing her to loose her hold of the cable. To lessen 

 the expense, which might otherwise interfere with 

 the project, the vessel could also be used as a call- 

 station for passing vessels and for those in distress. 



— - We reproduce from Science et nature a picture 

 of the statue of Claude Beinard, the eminent French 

 physiologist, which has just been erected before the 

 College de France. It was executed by Guillaume of 



the French institute, and, on the occasion of its un- 

 veiling, was accompanied by a eulogy by Beclard, the 

 dean of the faculty of medicine of Paris, a portion 

 of which is reproduced in Science et nature of June 6. 

 — N. de Miklouho-Maclay tells us {Proc. Linn, 

 soc. N. S. Wales, ix. 963), that during the years 1871 

 and 1872 no less than thirteen earthquake shocks 

 were felt on the Maclay coast of Xew Guinea. Upon 

 his return to that region in 1876, the mountain peaks 

 which in 1872 were covered with vegetation were 

 in places quite denuded, and portions of the coast 

 devastated by tidal waves. There were crevices from 

 one to three feet wide, and three or four feet deep; 

 and the depth of the sea was in some places apprecia- 

 bly altered. Since 1876 there have been only slight 

 shocks, which have occurred at the same time as 



