451 



2. On certain Laws of the liesistance of Fluitls. By Jolin 



Scott Kussell, Esq. 



3. Chemical Examination of the Tagua-Xut, or Vegetable 



Ivory. By Professor Counell. 



Tills remarkahle nut is now well known as being extensively 

 carved into ornaments, having the high i)o]ish and general appear- 

 ance of the finest ivory. 



It is a seed or nut of a jjalm called P]i i/teleplias macrocarpa, 

 which is found on the banks of the Magdalena river, in the republic 

 of ColumbiiX. 



For analysis the fine turnings of the vegetable ivory were em- 

 ployed. These were well rubbed in a mortar successively with cold 

 and hot water, and were then heated with hot alcohol The con- 

 stituents were found to be — 



Gum, ...... 6.73 



Legumin or Vegetable Casein, . . . 3. 8 



Vegetable Albumen, . . . .0.41 



Fixed Oil, . . . . . .0.73 



Ashes, ...... 0.61 



Water, . . . . . .9.37 



Lignin or Woody Matter, . . . .81.34 



100. 



In the ashes M-ere found phosphate of hme, sulphate of potash, 

 chloride of pota.'jsiuni, carbonate of Ume, and a little siliceous matter. 



The following Donations to the Society's Museum were 



announced : — 



14 Specimens of British Land and Fresh-water Shells. Presented 

 by the Honourable Mrs Macadam Cathcart. 



Block of Sandstone, with organic remains imbedded in it, found in 

 one of the dry docks at Leith, when enlarging it ; originally 

 from llo.syth Quarry, Pifeshue. Presented by Captain Patrick 

 Daix, RN. 



Portrait of James Mitchell, at the age of 46 years, well knoAvn, and 

 described in the Transactions of this Society, by the late Pro- 

 fessor Dugald Stewart and others, as the blind, deaf, and dumb 

 boy. This portrait was given by his sister, Jane G. Mitchell, 

 to, and was presented by. Sir Thomas Dick. Lauder, Bart. 



The following Donations to the Society's Library were 

 announced : — 



