382 
POPULAR SCIENCE REVIEW. 
possesses in sufficient proportions the elements essential to the discharge of 
the proper functions of the plant, this in its turn will be enabled to resist 
and paralyze the injurious influences which tend to affect it externally. 
See report of Baron Liebig’s discourse, in a pamphlet entitled — Lettres 
adressees d la Gazette de Lausanne , January, 1864. 
Population and size of Inhabitants of a Country dependent upon the Cha- 
racter of the Soil , is in effect the title of a curious essay by the late Feu 
Jobard, of Brussels. As it bears closely upon the subject of land culture, 
we give a notice of it here. The author first shows that a very large quan- 
tity of phosphates is required in building up the skeletal portions of the 
animal fabric, and then maintains that in the event of a deficiency in the 
supply of this material, the animal (man) will not attain his full size. 
He writes, “ Phosphoric acid is so essential to the well-being of plants, 
that lands which possess nitrogenous materials in abundance remain un- 
fertile without phosphates. This is why Asia Minor, Sicily, Palestine, 
Arabia Felix, Rome, and the plains of Babylon are barren, because of the 
enormous quantity of phosphate drawn from them by their vast popula- 
tions. This has occurred to all countries inhabited for a long period, with 
the exception of Egypt, but in the latter case, the numerous inundations 
bring down vast supplies of the phosphatic material from the regions of 
Upper Nubia. The reason why the size and number of inhabitants in 
Spain diminishes is, because of the want of phosphoric acid to give to the 
skeleton that development which was found among the ancient Gauls.”— 
Presse Scientifique des deux Mondes , Yol. II., Nov. 22. 
ASTRONOMY. 
Exterior Envelope of the Sun. — Mr. Dawes considers that some of the 
so-called new discoveries on the sun’s envelope are merely those which he 
himself described many years since. The large apertures and high 
powers now generally made use of give to the sun, when scrutinised under 
favourable atmospheric circumstances, an appearance so different from 
that presented by telescopes formerly in use, that it is not surprising that 
observers imagine they have made new discoveries. Mr. Dawes states 
that the mottled aspect of the sun can be seen with a good refractor of 2J 
inches aperture, and a power of 60. Examined with an aperture of 6 or 
8 inches, he finds that the surface is made up of luminous masses im- 
perfectly separated from each other by rows of minute dark dots, which 
are exceedingly close together, the intervals between them being less 
luminous than the general surface of the sun. The masses thus incom- 
pletely separated are of every variety of irregular form, those which are 
described by Mr. Nasmyth as “ willow leaves,” viz. — long, narrow, and 
pointed, being the rarest of all. These last are generally situated in the 
immediate vicinity of large spots, and even on the penumbrse. They 
sometimes project towards the spot itself, the edges of which appear 
ragged, “ looking much like a piece of coarse thatching with straw, the 
edge of which has been left untrimmed.” Mr. Dawes does not agree with 
Sir John Herschel that these minute dark dots or pores are in a constant 
