223 



For the botanist, the ramble yielded nothing fresh, the extent of ground 

 covered being too great to allow of that thorough exammation which is necessary 

 for the exploration of a district. As in other instances. Campanula paiula was 

 found marking out the Comstone ridges, while the downs and elevated places 

 were adorned with the characteristic Galium saxatile ; the marshy hedge-bottoms 

 yielded G. Witheringii and palustris, and the walls were becoming golden-hued 

 with the rich yellow flowers of Sedum rupestre. In one instance, Sempervivum 

 tectorum, evidently wild, was found growing on a wall. 



At 6 p.m., the hungry and tired explorers met at the Falcon, and recruited 

 their strength by an exceUent dinner. During the pleasant hour which they 

 afterwards spent together. Dr. Rowan exhibited and explained a simple con- 

 trivance for ascertaining in a few minutes, the percentage of lime in any given 

 sample of limestone, and proceeded to experiment with it in a very successful 

 manner. It consists of a large glass jar or bottle with a perforated cork, into 

 which fits a smaller glass vessel and a glass syphon, one leg of which reaches 

 down to near the bottom of the jar. A small tube also passes through the cork. 

 A given quantity of limestone, bruised, with a small quantity of water is put 

 into the jar ; the whole is then weighed ; the inner vessel is fiUed with hydro- 

 chloric acid, and the jar is exhausted of air by suction through the tube. A 

 partial vacuum being thus created, the acid rushes through the syphon, and faUs 

 upon the limestone, producing an eServescence. The carbonic acid being expeUed 

 through the tube, the residuum is chlorite of lime. On the jar being again 

 weighed, the loss from the former weighing is deducted, and the actual amount of 

 lime is thus ascertained. Of course, the weighing is a matter of great nicety, 

 but the saving of time in analysis by this method is very considerable, while the 

 practical value of a cheap and easy test of the value of limestone in agriculture 

 is obvious. 



The party broke up at 8 p.m., having spent a very agreeable day. 



