366 Scientific Intelligence. 



to powder. The specific gravity of trachyte does not exceed 2.7, that of 

 graystone 3.0 ; while basalt occasionally reaches 3.50. 



A third test is the colour of the glass before the blowpipe. That from 

 trachyte is light- coloured, and nearly transparent. That from graystone 

 is darker, and having numerous green or black specks, often of a green co- 

 lour. Basalt swells into a dark-green or black enamel. 



Leucite has not been found in trachyte, rarely in graystone ; but qftener 

 in basalt. 



Olivine has never been found but in basalt, and it appears to replace 

 the felspar in part, or wholly, but only when the augite is in excess. 



45. South African Botany, 6;c.~ It is well known, that Mr James Bowie, 

 an excellent botanist and general naturalist, has been for many years em- 

 ployed in collecting plants for his Majesty's gardens of Kew, in the inte- 

 rior of Southern Africa ; and that, in consequence of the late system of 

 retrenchment in the government expenditure, he has, to the great regret 

 of every one attached to botany, and alive to the interest of the Royal 

 Gardens, been recalled. 



Mr Bowie had already travelled to the distance of 200 miles from the 

 Cape of Good Hope ; and of the exceeding value of the collections sent to 

 Kew, the writer of this article can bear ample testimony. He now pro- 

 poses to return to the Cape, and again explore the interior at his own risk, 

 relying for a remuneration for his great expenditure, upon the prospect of 

 disposing of what he may collect to the naturalists of this country. 



Under this impression, he offers to collect plants, and other subjects of 

 natural history, for those who may be inclined to favour him with their 

 commissions, upon the following terms : — 



Dried Plants, well preserved specimens, at L.2, 10s. the hundred 

 species. 



Seeds, L.5 per hundred do. s 



Bulbs, (Ixiae, &c.) 10s. per hundred, larger ones, Is. to 2s. 6d. each. 



Living Plants, 2s. 6d. each species. N.B. — If small succulents, three 

 or more kinds will reckon as one. 



Strelitzice, Zamioz, &c. and plants of similar size, 5s. each. 



New Species will be charged somewhat higher. 



Birds.— For small birds' skins, and to the size of doves, one shilling each 

 specimen. From that size, and upwards, in proportion, to that of a vul- 

 ture or eagle, 7s. as the highest price. Birds for dissection, preserved in 

 spirits, (cask included,) L.5 per hundred, without regard to size. 



We think we are doing, a service to men of science in this country, in 

 recommending so deserving a naturalist to their attention ; and we heartily 

 wish him success in his undertaking. 



Mr Bowie's address is Kew Green, Surry. 



VEGETABLE PHYSIOLOGY. 



46. Professor Decandolle on the Lenticello?.-— Professor De Candolle of 

 Geneva, has lately published a valuable memoir in the " Annales des Scien- 



