April 6, 1899] 



NA TURE 



539 



Texp^rience humaine ; quand je professais, il y a long- 

 temps, que I'hydrogene etait plus pr^s des metaux que de 

 toute autre classe de corps ; j'emeltais des opinions que 

 les ddcouvertes actuelles viennent confirmer et que je 

 n'ai point a modifier aujourd'hui." ' 



One of the replies to my working hypothesis was that 

 the various chemical elements probably existed in 

 different proportions in the different stars, and that it so 

 happened that in Vega and Sirius one of them, hydrogen, 

 existed practically alone. 



In 1878 I went further, and showed that thousands of 

 solar phenomena which had been carefully recorded 

 during the previous years could only be explained by 

 assuming that the changes in the various intensities of 

 lines in the line spectrum itself indicated successive dis- 

 sociations. I pictured the effect of furnaces of different 

 temperatures, and I wrote as follows : ^ 



" It is abundantly clear that if the so-called elements, 

 or, more properly speaking, their finest atoms — those 

 that give us line spectra — are really compounds, the 

 compounds must have been formed at a very high tem- 

 perature. It is easy to imagine that there may be no 

 superior limit to temperature, and therefore no superior 

 limit beyond which such combinations are possible, 

 because the atoms which have the power of combining 

 together at these transcendental stages of heat do not 

 exist as such, or rather they exist combined with other 

 atoms, like or unlike, at all lower temperatures. Hence 

 association will be a combination of more complex mole- 

 cules as temperature is reduced, and of dissociation, 

 therefore, with increased temperature, there may be 

 no end." 



In 1878 I went back to the study of the changes in the 

 line spectra in relation to the changes observed when 

 known compounds were dissociated, and after discussing 

 certain objections 1 submitted the conclusion that the 

 known facts with regard to the changes in line spectra 

 "are easily grouped together, and a perfect continuity of 

 phenomena established on the hypothesis of successive 

 dissociations analogous to those observed in the cases of 

 undoubted compounds."-' 



It is thus seen that the conclusions to which my 

 spectroscopic work up to the year 1880 had led me, tended 

 in exactly the same direction as that indicated by more 

 purely chemical inquiries thus referred to by Berthelot in 

 that year : — 



" L'etude approfondie des proprietes physiques et 

 chimiques des masses clementaires, qui constituent nos 

 corps simples actuels, tend chaques jour d'avantage a les 

 assimiler, non a des atonies indivisibles, homogenes e( 

 susceptibles d'eprouver seulement des mouvements 

 d'ensemble, . . . il est ditificile d'imaginer un mot et une 

 notion plus contraires a I'observation ; mais is. des edifices 

 fort complexes, douds d'une architecture specifique et 

 animes des mouvements intestins trfes varies."^ 



Norman Lockyer. 



DRIFT-BOTTLES AND SURFACE CURRENTS. 

 'X'HE rather anomalous results arrived at by some 

 ^ recent investigators who have employed the float 

 or bottle method of ascertaining the surface movements 

 of the waters of the sea, make the discussion of a large 

 number of these observations of special value at the 

 present time. Such is to be found in Dr. Schott's able 

 and elaborate paper on tlie " Flaschenposten " in the 

 possession of the Deutsche Seewarte, published a short 

 time ago in the Archiv. 



After an historical introduction, in which it appears that 

 the earliest recorded current observation of this kind is 



1 " Chemistry of the Sun," p. 205. 



- Proc. Roy. Soc, vol. x.wiii. p. 169. S 



■^ Roy. Soc. Proc.t vol. xxviii. p. 179. 

 4 Comfitcs rendus, 1880, vol. xc. p. 1512. 



'Chemistry of the Sun,' 



about a century old, Dr. Schott describes the material at 

 his disposal, which consisted of about 600 records 

 found up to the end of the year 1896. One important 

 point here brought out is that no consistent difference 

 can be observed in either direction or rate of drift between 

 empty floats and floats loaded so as to ensure complete 

 immersion. 



In arranging the records obtained from each of the 

 great oceans, the first place is, of course, given to the 

 North .Atlantic, which includes no less than 452, or 70 

 per cent, of the whole. The North Atlantic records are 

 subdivided into six sections — those from floats set adrift 

 in the North Sea and the English Channel ; in the west 

 wind region north of 30' N. lat. ; in the north-east trade 

 wind region ; those in the south-east trade wind region 

 which were recovered beyond its northern limit ; those 

 in the region of south-west monsoons, and in the Medi- 

 terranean. The charts appended to the paper, of which 

 w-e reproduce a specimen, contain only a selected number 

 of the drift-tracks dealt with ; full details are given in 

 tabular form. In the cise of the other oceans, the whole 

 of the observations are represented ; the South .Atlantic 

 and the Pacific are each treated as a whole, while the 

 Indian Ocean is divided into the monsoon region, the 

 south-east trade belt, and the " brave west winds.'' 



Summing up in a final paragraph, Dr. Schott concludes 

 that on the whole the method of drift-bottles yields 

 valuable information both as to the direction and speed 

 of surface currents. From this, however, the monsoon 

 regions are expressly excepted : the number of bottles 

 found within the period of one monsoon is necessarily 

 small, and the few found give unsatisfactory results. As 

 specially favourable instances. Dr. Schott quotes his 

 results in the Bay of Biscay, disproving the existence of 

 RennelTs current (no reference is made, by the way, 

 to the work of Hautreux) ; in the West Indies, where 

 the concentration of immense quantities of surface-water 

 from the coast of Portugal and from the South .-Vtlantic 

 is clearly shown ; in the west wind drift of the southern 

 hemisphere, and in the splitting of the southern equa- 

 torial current off the east coast of Madagascar. In this 

 connection special stress is rightly laid on the record of 

 two bottles, one loaded with sand and the other not, 

 thrown overboard from the s.s. Paranagtia in 13' 49' 

 N. lat. and 25' 34' W. long., and picked up together on 

 the island of Santiago (Cape Verd Island) after a 

 journey of 131 miles in twenty-one days, the direction 

 being north-east by east with a weak current (whose 

 existence was shown by independent observations 

 recorded in ships' logs), and against the wind blowing at 

 the time. In estimating the speed of current, the float 

 method is found to be much less valuable, inasmuch as 

 we can rarely be certain that the float is picked up 

 immediately after it has reached the spot where it is 

 found. Reasonably accurate estimates can only be 

 looked for where a number of floats gives approximately 

 the same result. 



The justness of Dr. Schott's conclusions, so far as they 

 go, seems to admit of little doubt, but we could have 

 wished that his final statement of them, which will 

 probably be much more widely read than the detailed 

 discussion in the body of the memoir, had been ex- 

 pressed in a more guarded manner, and that to it he 

 iiad .-idded a note of n-arning, pointing out not only 

 the extremely limited nature of the information aftbrded 

 by the method, but the great risk of misinterpreting its 

 results. Taking first the question oi din-ethm of surface 

 currents : on the whole, the surface currents in perfectly 

 open sea, clear of all land influences, follow the direction 

 of the wind, and the float or bottle naturally takes the 

 course common to both. Near land, the direction of the 

 surface current is determined by three factors : first, and 

 most important, the form of the coast line ; second, the 

 prevailing wind; and third, a gravity factor, due to 



NO. 1536, VOL. 59] 



