12 J. Waterliouse — Use of Eosin in Fltotograplung tlie Spectrum. [J Air. 



under Lieut. -Col. Tulloch to come up and chastise the village of Pangti, 

 which was effectually done on the following morning, the whole party re- 

 maining encamped there afterwards. 



The precise cause for such an attack so near Golaghat;? is not yet 

 known, but it would seem to indicate that the Nagas of the village of Ninu 

 were not sufficiently punished for the terrible massacre committed there last 

 season on Lt, Holcombe's party, or else that it is impossible to make these 

 savages, inhabiting closely approximate villages, comprehend or realize the 

 lessons which take place so close to them, so hostile are they even amongst 

 themselves, one village with another in close proximity. 



He expressed a strong hope that the services of that intrepid explorer 

 and excellent officer, Capt. Butler, might not long be lost to the Government. 

 It would be almost a national calamity, if such a valuable officer lost his 

 life under such circumstances. 



Capt. Butler was very ably supported by Lt. Woodthorpe, who 

 had now obtained considerable experience amongst these hill-tribes, 

 and it was to be hoped that this temporary disaster might not have the 

 eflFect of preventing the present good policy of the Government of India 

 from being carried out, until we had a thorough knowledge of the whole 

 geographical situation round the British border of Asam, which has so 

 long baffled all attempts at its investigation, but has now been declared so 

 essentially necessary for all administrative purposes of that Province. 



The completion of our geographical knowledge of the tracts held by 

 these hill-tribes between the British territory of Asam and Burmah, is 

 absolutely essential to the depiction of the entire line of the British Eastern 

 Frontier.* 



2. On the influence of Eosin on tlie PlwtograpMc Action of the Solar 

 Spectrum upon the Bromide and Bromoiodide of Silver. — By Capt. J. 

 Wateehotjse, Asst. Surveyor General of India. 



At the November meeting of the Society I exhibited some plates show- 

 ing the action of tlie red rays of the spectrum on dry films of collodio-bro- 

 mide of silver stained with a blue dye. I have since received from Berlin a 

 sample of a new red dye called Eosin, and have obtained results on dry 

 bromide plates stained with it, which are of particular interest from the fact 

 that the photographic action of the spectrum on such plates is entirely 

 different to its ordinary action on an inistained plate, i. e., instead of the 

 maximum of action being in the indigo and violet it is in the green and yellow, 

 as will be seen in the accompanying photographs and in fig. 5 of Plate I. 



* Since the meeting took place, the sad news of Capt. Butler's death on the 7th 

 January has been received, and the Government G-azctte of the 22nd instant contains a 

 handsome tribute to his character and worth. 



