Society of Jni'iquaries. 363 



dener's attention to the supply of that kind of air most easi- 

 ly assimilated bv the lun^s or respiratory organs oi the diffe- 

 rent species of bulbous- and tuberous -rooted plants, and 

 thereby find a new pabulum vitce vegelahilis. It is, how- 

 ever, certain that wc are yet very ignorant of the mdcfmUe 

 improvability of vegetables, and of the best means ot mul- 

 tiplving them for the use of animal life. 



May 22. The President in the chair.— A letter from Mr. 

 Martin to the right honourable Mr. Greville, gave a brief 

 description of a kind of mineral bason, or surface of a 

 country, extending 100 miles in length, and 20 m breadth, 

 through Wales, in Glamorgan and adjoining shires, which 

 consiS'ts principally of iron ore and coals. Brief as this 

 mineralogical topography is, it were to be wished that we 

 had similar sketches of all the districts in Great Britain, as 

 wc might thence form more accurate ideas of the geology of 



the kingdom. 



AletterfromMr. Dunlopto sir C. Blagden, bart. wa:5 



likewise read, containing a description of an instrument 

 newly invented bv him, to be substituted for the common 

 quadrant and sextant now in use, and by means of which 

 the numerous errors occasioned by atmospheric retraction, 

 and in taking lunar observations, &c. are to be completely 

 obviated. Should this invention be found to answer these 

 pretensions, it will be of inestimable consequence to navi- 

 gators, as such is the imperfection of our present instru- 

 ments, that no two observers can bring the sun to the same 

 altitude on the quadrant, often diflering from 4 to 7 miles 

 in their observations : an endless source of errors and mis- 

 calculations in the course of a long voyage. 



SOCIETY OF ANTiaUABIES. 



May 1. The lord bishop of Salisbury in the chair— A 

 lulf-lcncrth portrait of sir Walter Raleigh was presented to 

 the society by sir W. Skeffington, bart. In the letter which 

 accompanied' this present, it was acknowledged that the 

 paintinc^ was only a tolerably old copv of some original : 

 the upp^er part indeed was very well executed, but .he hands 

 were extremely incoireet and unnatural. _ 



DesiiTiis 



