428 



SCIENCE. 



[N. S. Vol. II. Xo. 40. 



tion, and in 1835 the Governrnent employed 

 Colonel Chesney to make a survey of the 

 Euphrates Valley in order to ascertain 

 whether that river would enable a practica- 

 ble route to be formed from Iskanderoon or 

 Tripoli, opposite Cyprus, to the Persian 

 Gulf. His valuable surveys are not, how- 

 ever, on a sufficiently extensive scale to en- 

 able an opinion to be formed as to whether 

 a navigable waterway through Asia Minor 

 is physically practicable, or whether the 

 cost of establishing it might not be prohibi- 

 tive. 



The advances of Eussia in Central Asia 

 have made it imperative to provide an easy, 

 rapid and alternative line of communica- 

 tion with our Eastern possessions, so as not 

 to be dependent upon the Suez Canal in 

 time of war. If a navigation cannot be es- 

 tablished, a railway between the Mediterra- 

 nean and the Persian Gulf has been shown 

 by the recent investigations of Messrs. 

 Hawkshaw and Hayter, following on those 

 of others, to be perfectly practicable and 

 easy of accomplishment ; such an undertak- 

 ing would not only be of strategical value, 

 but it is believed it would be commercially 

 remunerative. 



Speke and Grant brought before the As- 

 sociation, at its meeting at Newcastle in 

 1863, their solution of the mystery of the 

 Nile basin, which had puzzled geographers 

 from the days of Herodotus ; and the efforts 

 of Livingstone and Stanley and others have 

 opened out to us the interior of Africa. I can- 

 not refrain here from expressing the deep re- 

 gret which geologists and geographers, and 

 indeed all who are interested in the progress 

 of discovery, feel at the recent death of Jo- 

 seph Thomson. His extensive, accurate 

 and trustworthy observations added much 

 to our knowledge of Africa, and by his pre- 

 mature death we have lost one of its most 

 competent explorers. 



The report made to the Association on 

 the state of the chemical sciences in 1832 



says that the efforts of investigators were 

 then being directed to determining with ac- 

 curacy the true nature of the substances 

 which compose the various products of the 

 organic and inorganic kingdoms, and the 

 exact ratios bj- weight which the different 

 constituents of these substances bear to each 

 other. 



But since that day the science of chemis- 

 try has far extended its boundaries. The 

 barrier has vanished which was supposed 

 to separate the products of living organisms 

 from the substances of which minerals con- 

 sist, or which could be formed in the labora- 

 tory. The number of distinct carbon com- 

 pounds obtainable from organisms has 

 greatly increased; but it is small when 

 compared with the number of such com- 

 pounds which have been artificially formed. 

 The methods of analysis have been per- 

 fected. The physical, and especially the op- 

 tical, properties of the various forms of mat- 

 ter havebeen closely studied, and manj^ fruit- 

 ful generalizations have been made. The 

 form in which these generalizations would 

 now be stated may probably change, some, 

 perhaps, bj' the overthrow or disuse of an 

 ingenious guess at nature's workings, but 

 more by that change which is the ordinary 

 growth of science — namely, inclusion in 

 some simpler and more general view. 



In these advances the chemist has called 

 the spectroscope to his aid. Indeed, the 

 existence of the British Association has 

 been practicall}' coterminous with the com- 

 parativelj' newly developed science of spec- 

 trum analysis, for though Newton,* Wol- 



* Joaunes Marcus Jlarci, of Krouland in Bohemia, 

 was the only predecessor of Newton who had any 

 knowledge of the formation of a spectrum hy a 

 prism. He not only observed that the colored rays 

 diverged as they left the prism, but that a colored 

 ray did not change in color after transmission through 

 a prism. His book, Thaumantias, Uher ila arcu cceksii 

 deque colurum apparcntium naturn, Prag. 1648, was, 

 however, not known to Newton, and hadnoinfluence 

 upon future discoveries. 



