Royal Society of Edinburgh. 305 



Mr Mitsclierlich died in the present j^ear. 



His experiments and disquisitions tended to establish the rule 

 that bodies crj^stallizing in the same shape (isomorphous) have an 

 analogous chemical composition — throwing great light on chemical 

 classitication, and giving us one of the greatest generalizations 

 (after the Atomic theory) which chemistry has gained by the re- 

 searches of philosophers. 



When I have laid before you these slender memorials of our de- 

 ceased brethren, I may claim to have discharged the real duty of my 

 office to-night. If indeed I were worthy to fill the chair in which 

 your favour has placed me, — if I had, like some of our distinguished 

 Fellows, a knowledge of all science, or even a special acquaintance 

 with anyo??e, — it would be my duty to submit to you a survey, or at 

 least some outline, of the progress of science among us and among 

 our neighbours. But for such a task you know me to be ill qualified. 

 I should not venture to speak in the language of science any- 

 where, and least of all in the presence of the men whom I now see 

 around me. 



There are subjects, however, in which scientific men and men of 

 no science feel an equal interest — which must engage the attention 

 of every person of common intelligence. 



Among these is the great step recently made in African geo- 

 graphy — the discovery of the head of the Xile. Xo other geogra- 

 phical discovery can ever compare with tLjis. It is not the solution 

 of a puzzle in the Geographical Society. It is removing the 

 " Tmpossihle' — the very type of impossibilities — from our books. It 

 is opening to the whole world the mj^stery which was a mystery 

 even to the initiated. Poets have lost a topic ! What philosophers 

 and historians guessed and speculated about, is now written down 

 plain on the map. That is now clear which has been wondered at 

 since men began to ask the meaning of anything. We have lost 

 the oldest subject of curiosity in the world ! 



A grave, prosaic mind loses its equanimity, and gives way to the 

 charm of romance at the thought of the veil being raised that 

 has for so many thousands of years covered the head of the great 

 mysterious river which was w^orshipped of old — not more for its 

 beneficent overflowings, regular as the seasons, yet unaccountable, 

 than because of its unknown, unapproachable source. 



I do not mean that the facts which our travellers have brought 

 to light run counter to the conclusions of former geographers. On 

 the contrary, I think the body of history on the one hand, the 

 speculations of science on the other, had prepared the world for 

 such a discovery. G-lancing at the ancient, I mean the classical 

 authorities, without arraying them before you, I may say that among 

 innumerable fables and much unphiiosophical reasoning, they 

 almost concur in giving the Nile its source in a mighty lake — some 

 say two immense lakes — fed by periodical rains, — fed also, say some, 

 by subterraneous streams flowing from the west (these subterraneous 

 rivers were favourites with the wonder-loving naturalists of old). 



