42G Proceedings of the Asiatic Society. [No. 5. 



47. — Sarawaddi is equally on the river Irrawaddi. 



48. — Kyouktarau is also on the river. 



49. — From this point northward along the river, as far as the 

 map extends, the greenish tint used for tertiary rocks may be 

 continued. 



50. — " Silurian beds" entered near Patanago to be erased ; all 

 tertiary. 



51. — The words " transition limestone" near 18^ N. lat. to be 

 erased, all is tertiary. 



52. — Again " transition limestone" (at 19* N. lat.) ought to be 

 removed, and the words " Silurian slate" under Pukcm-gyi ought to 

 be removed : none being there. 



53. — In colouring in many cases there has been a great want of 

 care. At N. lat. 28i and East long. 68° to 71° a case of this kind 

 may be seen, when the colours on the two different sheets do not 

 join within 120 miles ; and several other cases might be quoted. 



The scale of colours appear to be altogether deficient in clearness 

 and distinctness, the tints approaching each other too closely. 



Thomas Oldham, 

 C. B. Young, Capt., Engineers. 

 H. L. Thuillier, Major, 

 E. Spilsburt, M. D. 

 A. Geote. 

 H. Piddington, Curator, M. E. G. 



The report was approved and adopted. 



Communications ivere received—- 



1. — Prom Mr. Grey, Secretary to the Government of Bengal, 

 forwarding Dr. McNamara's report on the Iron Ores last sent from 

 Assam by Col. Hannay. 



The report is as follows : — 



The iron is present in the form of the magnetic oxide, the masses 

 of which are scattered through a large proportion of silicious mat- 

 ters. The ore contains on an average 40.2 per cent, of metallic iron. 



By placing some of the ore in a basin, and washing it with a 

 stream of water, I was able, very quickly and with very little trou- 

 ble, to obtain an ore containing 65 per cent, of metallic iron, these 

 specimens may therefore be considered very rich as regards the 

 amount of iron in them. 



