146 



HARDWICKE'S SCIENCE-GOSSIP. 



black Loch Kander with its precipitous corries, the 

 rocks at the head of Glen Callater, and above these 

 appeared the hill forming the watershed of the Clova 

 mountains. Descending to the snow corrie, where in 

 the water running from the snow we got some 

 saxifrages, we soon came to Azalea procumbens and 

 JSpilobium alpinum, and coming down by some 

 roughish descent the ground near Loch Callater was 

 covered with Arbutus Uva-ursi. 



Another day was spent in walking from Braemar 

 to Loch Callater, and following the western side of 

 the lake, near the head of which we came upon 

 Veronica becca'ounga, dwarfed to a couple of inches, 

 and with bright blue flowers contrasting beautifully 

 with Saxifraga aizoides, with which it occurred. 



On the moorland leading up to Loch Kander, Carex 

 pauci/lorus and RubusChamixmorus, the latter in flower, 

 were gathered ; by the stream issuing from the loch 

 Salix arenaria and Lapponum occur, and in the 

 lake itself grew Callitriche hamulata. The corries 

 round the lake were rich with rarities, rolypodium 

 alpestre being especially fine. Rhodiola rosea, Saxi- 

 fraga hypnoides, with the varieties gemmipara and 

 sponkemica, Epilobiitm anagallidifolium, A /sine 

 vertia, Polygala vulgaris approaching grandiftora, 

 J uncus trifidus, triglumis, Carex pulicaris, pilulifera, 

 and strange dwarfed specimens of Carex jlava, and 

 some fine Asplenium viride, were soon gathered. At 

 some elevation on the precipitous rocks were gathered 

 Salix reticulata, lauata, and herbacea, Carex capil- 

 lars, and abundance of Cochlearia alpina, Saussurea 

 alpina, not quite in flower, and Hieracium pallidum, 

 chrysanthum, nigrescens, and ccesium. This dark lake 

 Kander, like so many of our British mountain lakes, 

 is situated on the east side of the mountain, and it is 

 probable that their position may be owing to glacial 

 action, the great amount of snow and ice remaining on 

 the colder side. Lakes in this position are to be 

 seen on Ben Nevis, Cairngorm, Loch na Gar, and in 

 many of the Welsh mountains. In the Lake District 

 the difference between the south-western and north- 

 eastern sides of the mountains is very marked, and 

 High Street, Helvellyn, Scawfell have also these 

 mountain tarns on the eastern side. 



To return, however, to the cliffs about Loch 

 Kander, where some good scrambling was enjoyed in 

 getting on to the rocks about the Break Neck water- 

 fall, where magnificent J uncus triglumis and Carex 

 atrata occurred. Then came a grassy place of a less 

 steep inclination, where A spidium lonc/iitis grew almost 

 by hundreds ; here too were found Lcontodon pratense, 

 Carex alpicola and speirostachya. By the waterfall 

 grew Veronica alpina, not in flower but with a 

 bluish purple about the capsule ; the variety mon- 

 tana of Alchemilla vulgaris ; the cudweeds G. supiuum 

 in both its states pusillum and fuscum; a form of 

 Carex binervis, which at first looked like frigida, and 

 Salix nigricans, phylicifolia, andpseudo-glauca; Hiera- 

 cium anglicum, Vaccinia m uliginosum, Air a montana. 



Silene acaulis and Saxifraga oppositifolia both occurred 

 in flower, although very sparingly. At the boggy head 

 of the lake Carex vesicaria, Potamogeton polygonifolius, 

 and other common plants occurred, but after such 

 a feast of rarities our botanical ardour required stronger 

 stimulus than these to linger on our homeward walk» 



THE HYPOTHETICAL PLANET. 

 By J. J. Plummer, M.A., F.R.A.S. 



THERE are few pages in the history of astronomy 

 that will read more strangely in the future 

 than the belief which has been entertained so firmly 

 during the last twenty years in the existence of a 

 planet interior to Mercury, and which is generally 

 known by the name of "Vulcan." No doubt much 

 of the tenacity that has been shown in this matter is 

 attributable to the respect due to the genius of the 

 late M. Leverrier, who had a profound belief in the 

 reality of its existence, and than whom there was 

 none other more capable of estimating the value of 

 the evidence in its favour. He subjected, one after 

 another, the motions of all the major planets to the 

 test of the most refined analysis, and had shown in 

 every case how accurately the law of gravitation 

 accounted for all the minor disturbances (technically 

 called perturbations) which the several planets produce 

 upon each other by their mutual attractions. One, 

 and one only, appeared to defy his treatment and 

 the Newtonian law alike, and this, the planet Mercury, 

 the smallest of the larger planets, and the nearest to 

 the sun. The direction of its elliptical orbit is 

 certainly shifting slowly, and the attractions of the 

 neighbouring planets were by him deemed insuffi- 

 cient to account for the fact. No one had better 

 reason to remember than Leverrier, how similar 

 outstanding perturbations had been reduced to order 

 by the discovery of the planet Neptune at the other 

 extremity of the solar system, and it is, therefore, not 

 surprising to find him confident that a like result 

 would be achieved in this case. Indeed, so far as the 

 theoretical side of the question is concerned, the case 

 appears to be completely in favour of an undiscovered 

 planet interior to Mercury, and the full weight of this 

 evidence was doubtless not only felt, but exaggerated 

 in the mind of the great French astronomer. 



The difficulty of verifying practically these conclu- 

 sions by the actual discovery of a planet is very con- 

 siderable, owing chiefly to the close proximity to the 

 sun which such an object would constantly maintain, 

 and the only hope of bringing the telescope to bear 

 upon the actual body would necessarily be during an 

 eclipse of the sun, or on the occasions when the planet 

 might project itself on the solar disc. There are not 

 wanting records, more or less definite and precise, of 

 the appearance of minute spots upon the solar orb 

 unlike the well-known sunspots, but unluckily no 

 practised astronomer has yet succeeded in securing a 



