Dr. Balfour's Botanical Exewtsimx. 209 



If tlio weight be let fall from a certain height, elongating the spring 

 by impact^ it was shown that registered elongation, or maximum elon- 

 gation would exceed that due to the weight W, by a quantity equal to 

 a mean proportional between this elongation, and the same increased by 

 double the height fallen through. This latter m^an is the direct mea* 

 sure of the influence of the inertia of W, or its momentum, the 

 mechanical effect accumulated in the dynamometer spring. 



28<A February y 1844, — The President in the Chair. 



Messrs. George Greig, Alex. M'Nab, and George Lish, were ad- 

 mitted Members of the Society. 



A vote of thanks was given to Mr. William Murray, Convener, 

 and the other members of the Committee who made the arrangements 

 for the conversational meeting held on the 21st. 



A spirit lamp without a wick, belonging to Professor Maconochio, 

 was exhibited, and explained by Dr. Balfour. It consisted of a me- 

 tallic saucer, in which the spirit is deposited, and of a semi-globular 

 cap, with a central perforation, which fits into the former. 



Mr. Keddie gave in a Report of the monthly meeting of the Bo- 

 tanical section held on the 26th. 



The following paper was read. 



XLVIII. — Short account of a Botanical Excursion to Galloway and 

 Dumfriesshire, in August, 1843. By J. H. Balfour, M.D., Regius 

 Professor of Botany. 



Believing that an account of an excursion through some of the 

 richest botanical counties in the Lowlands of Scotland, will not be 

 uninteresting, more especially when accompanied with the exhibition 

 of specimens, I have been induced to bring the following communi- 

 cation before the members of the Philosophical Society. 



The pleasure which we derive from excursions like that I am now 

 to notice, enhances in no small degree the interest of our botanical 

 pursuits. The very sight of the specimens we collected recals many 

 pleasing associations ; and tliese dried forms of vegetable existence tell 

 more eloquently than words, many a tale of adventure by flood and field. 



The examination of the Flora of a country is an object of import- 

 ance, as leading to the determination of interesting points connected 

 with botanical geography. In the excursion through the counties of 

 Wigton, Kircudbright, and Dumfries, our party bore this object 

 steadily in view, and we have been able to make up a pretty full cata- 

 logue of the plants of the district. The plants collected were in 

 many cases rare, and one or two of them are not found in any other 

 counties in Scotland. 



