508 WITT'S REPORT ON SEA-WATER. [June 22, 1857. 



determination to do my best, and the hope of distinguishing myself, 

 bore me up. I very much regretted that boats especially adapted 

 for the purpose had not been built in England. If this had been 

 done, the great and almost insurmountable difficulties I sustained at 

 Wadi Half eh would have been in a great measure obviated ; and had 

 I left Cairo at the proper season I should have experienced much 

 less trouble altogether. When I heard that this expedition was 

 abandoned, it was a great source of satisfaction to me to know that 

 my conduct had been appreciated by the Eoyal Geographical 

 Society. 



The President said, they must all feel proud of the prowess of their 

 young couatryman. He must remind them that M. d'Escayrac, the head of 

 the expedition, was the author of a valuable work on the geography of Sudan, 

 and he only regretted that the dissensions which had broken out in his camp, 

 had prevented him from joining Mr. Twyford at the cataracts of the Upper 

 Nile, and thus carrying the expedition towards its ultimate destination. 



The fifth Paper read was — 



5. Report of the Expedition for the Exploration of the Rewa River and 



its Tributaries, Na tite Levie', Fiji Islands. By Dr. Macdonald, k.n. 



Communicated by the Admiralty. 



[This Paper will be published in full in the next Journal.] 



The sixth Paper read was — 



6. Report on the Specific Gravity of the Sea- Water on the West Coast of 

 Africa. By Henry M. Witt, f.c.s. 



Koyal College of Chemistry, April 17, 1857. 

 Sir, — The samples of sea-water collected on the western coast of 

 Africa by Dr. Campbell, and placed in my hands by you, were, I 

 regret to say, far too small to admit of chemical analysis. 



The colour which the sea had acquired by the influx of a large 

 river you mentioned as being peculiar, and were desirous of informa- 

 tion as to the nature and amount of the colouring matter : all that I 

 have been enabled to ascertain on the subject is, that it was evi- 

 dently a suspended yellow substance which modified the usual green 

 colour of the sea ; this suspended matter had separated from the 

 water in the samples submitted to me, and appeared curiously light 

 and flocculent, so that it would suggest for itself a more or less or- 

 ganic origin ; but its amount was really small, in some of the samples 

 only just visible : so that to have made a chemical examination of it 



