189 



lying from cue to two inches in diameter and about ten inclies long — and 

 also flasks. Any number may be used at the same time, set about six 

 inches apart. He has frames for thirty-six. It is best to make the fun- 

 nels pear-shaped, to allow their edges to slip into the tube^ that any 

 drops of condensed moisture may not fall outside. 



Mr. Britton also exhibited several mounted burettes for volumetric 

 analysis of the kind described in the Journal of the Franklin Institute, 

 for May 1870, and which he has had in use for more than nine years. He 

 exhibited them to show that the one exhibited by Dr. Geo. A. Koenig, 

 at the meeting of the Society, held August 21st, 1874, ditiered in no es- 

 sential feature from them. 



Mr. Britton had tried wood, leather, lead, tin, glass, india-rubber and 

 cork, for the stopper or valve. He preferred close-grained cork when 

 using solutions of per mangenate and bichromate of potash, and this after 

 five thousand iron determinations with it. Glass be prefrfrred to all other 

 substances when using acids or strong alkaline solutions. 



The graduation was on white paper behind the tube. The thumb 

 knob of the screw was behind the frame, but the spring and valve was 

 in front. This arrangement he preferred. The contents of the tube 

 could be discharged much faster than necessary for analytical purposes, 

 or so slow that only a fraction of a drop could be caught on the stirring 

 rod and conveyed to the solution to be tested in the vessel beneath. 



He also exhibited an adjustment of the spring and screw to the rod- 

 stoppered burette. The burette was mounted on a stand. A spring 

 lever was on the top and connected at one end with the rod-stopper, and 

 at the other end with a metal rod. The latter extended down the back 

 of the instrument to near the bottom, and had attached to it a thumb- 

 screw arrangement. By simply turning the screw the stopper could be 

 completely controlled while the eye watched the flow. 



Mr. Britton referred again to the Rocky Mountain coals exhibited at 

 the last meeting, simply saying in advance of analysis that they were all 

 coking coals. 



Mr, Poole obliged the members present with descriptions 

 of the coals of Nova Scotia, and of the character of the gold 

 quartz, veins, and present condition of the gold-mining in- 

 dustry of the province. 



Dr. LeConte offered for publication in the Proceedings, a 

 list of North American lepidopterse (platypterices, &c.,) with 

 notes by Augustus R. Grote, of Albany. 



Minutes of the last meeting of Officers and Members in 

 Council, were read. 



Pending nominations, 'No. 764, was read. 



Mr. Fraley nominated in behalf of the Committee of 

 Finance, Mr. J. Sergeant Price, to fill the vacancy left by the 



