June 22, 1883.] 



SCIENCE. 



581 



the fermentation, and smaller quantities of ammonia, 

 nitrous oxide, nitric oxide, nitrites, and probably 

 amide-like bodies, were obtained. The action has 

 been shown to take place in soils rich in organic 

 matter, wlien excluded from the air; and a small 

 quantity of active soil may infect a large amount of 

 soil which has been sterilized by heat. — (Bied. centr.- 

 blatt, 1883, 82.) h. p. a. [1113 



Butt and tip kernels of corn. — In a number 

 of sprouting trials at the Ohio agricultural experi- 

 ment-station, corn taken from the butts of the ears 

 produced larger and stronger radicles than that from 

 the tips, while that from the middle of the ear was 

 intermediate in this respect. The proportion of 

 seeds which sprouted was: tip kernels, 70.8 % ; mid- 

 dle kernels, .58.2 % ; butt kernels, 76.1 %. — {Country 

 gentleman, May 10.) H. P. A. [1114 



GEOLOGY. 



The Balkan peninsula. — In the tenth number 

 of Petermann's mittheilungen for 1882, Toula pub- 

 lished a geological map of this region, which gives us 

 a better idea of the geology of that much-disputed 

 country than any thing yet published. By a mistake, 

 the region between Aiwadschik and Kopriikoi, in 

 Bulgaria, was colored as Jurassic instead of eocene. 

 With this exception, this map, in sixteen coloi-s, is 

 fully up to Petermann's usual standard. Toula now 

 publishes a map on the scale of 1: 2,500,000, on 

 which, by means of twenty-five different lines, he 

 shows the routes travelled over by different geologi- 

 cal explorers in this region from the days of Herder, 

 Bou^, and Viquesnel (1835-37), down to the present 

 time, and in the accompanying ten pages of text 

 gives a brief account of the country visited, and a 

 historical sketch of the work done by each author. 

 — {Mitth. c/eogr. gesellsch. Wien, 1883, 25.) j. b. m. 



[1115 



Origin of the carboniferous limestone of 

 Belgium. — Dupont divides the carboniferous lime- 

 stone of Belgium into massive and stratified lime- 

 stones, the latter essentially detrital rocks with a 

 sedimentary appearance. The massive limestones 

 are due to the growth of corals, and are adapted to 

 the special dispositions of coral formations in fringing 

 reefs or islets, according to their distance from the 

 shore. The detrital limestones are subdivided into 

 two marked categories : the crinoidal limestone ; and 

 the limestone made up of coralline detritus, witli or 

 without interstratified beds of crinoidal limestone. 



These three divisions correspond with tlie three 

 faunas that de Koninck has distinguished, — the fauna 

 of Tournai, belonging to the crinoidal limestone; the 

 fauna of Waulsort, to the coral-reef limestones ; and 

 the fauna of Vis^, to the detrital limestones. The 

 stratigraphical study of the Belgian carboniferous 

 limestone thus becomes much simplified ; and the 

 problems suggested by the mixture of rocks of the 

 same chemical composition, but of different modes 

 of formation, can be solved by studying the mode of 

 formation, and the application of the stratigraphical 

 laws of coral phenomena established by the study of 

 the Devonian limestones. — {Bull. acad. roy. Belc/., 

 (3), V. no. 2.) J. B. M. [1116 



PHYSICAL GEOGBAPHY. 

 Causes of the fertility of land in the Canadian 

 north-west territories. — ^ Robert Bell showed, that, 

 with local exceptions, a vast fertile tract stretches 

 from the Bed River valley to the Liard River, a dis- 

 tance of some fourteen hundred miles, characterized 

 by a dark loamy soil of varying depth and nearly 



homogeneous consistency. The primary cause of 

 the fertility of this region may be found in the char- 

 acter of the subsoil, which consists largely of creta- 

 ceous marls and the comminuted material of the 

 glacial drift. The speaker ascribed to moles and 

 other burrowing animals the chief agency in the 

 process by which the black loamy soil was formed 

 out of this subsoil. Darwin had proved that in Eng- 

 land and some other countries earth-worms played 

 the chief part in the formation of mould. These 

 worms appear to be absent in the north-west, as well 

 as in most cold and sparsely settled countries, per- 

 haps due to the depth to which frost penetrates. 

 But in the north-west he believed the ground squir- 

 rels and moles more than made up for the absence 

 of worms. In the fertile area referred to, the old and 

 new mole-hills cover the entire surface, rendering it 

 ' hummocky,' as is easily observed after a prairie fire. 

 These animals are very active in autumn, digging 

 many more burrows than would appear to be of any 

 use to them. Each hummock thus thrown up covers 

 about a square foot, and buries all the grass, etc., on 

 this space. In this manner large quantities of vege- 

 table matter were ultimately incorporated with the 

 soil, which was also refined by the fact that the 

 stones and coarse gravel are left undisturbed below 

 the surface, so that in time they are more deeply 

 buried by the layer of mould produced. By au in- 

 teresting coincidence at the season when these bur- 

 rowing animals are most active, the prairie vegetation 

 is mature, and contains the greatest amoimt of sub- 

 stance. The coldness of the soil during a great part 

 of the year tends to jareserve the organic matter in it. 

 While the circumstances given were the direct cause 

 of the fertility, the ultimate reason was perhaps to be 

 looked for in the climate, which fosters the growth of 

 such vegetation as forms both the fertilizing material 

 and the food of the little workers, who mingle it with 

 the mineral portion of the soil. The action of frost 

 in comminuting the soil does not account, by itself, 

 for the introduction of the organic matter upon 

 which its fertility depends, and which is due to the 

 co-operation of the circumstances and agencies de- 

 scribed. — {Royal soc. Canada; meeting May 23.) 



[1117 

 The French 'Landes.' — E. Blanc describes the 

 great improvement effected in the formerly desert 

 region of south-western France by planting its sandy 

 surface with the maritime pine (Pinus pinaster). 

 The region is divided according to its surface-fea- 

 tures into five districts, locally named the Grande- 

 Lande, the Dunes, the Marensin, the Maremme, and 

 the Chalosse. The first includes half the entire 

 area, and, before the tree-planting, was an open plain 

 of loose sandy soil about two feet deep, lying on au 

 impermeable layer {alios) of sandstone cemented by 

 organic and ferruginous material. During winter it 

 was a great marsh ; in summer, a dry, sandy desert, 

 barely supporting its flocks of sheep. The absence 

 of stone for building and road-making was another 

 cause of its poverty. Since 1857, nearly the whole 

 surface has been covered with a continuous pine for- 

 est, from, which the resin is a valuable product. The 

 stilts of the old shepherds are no longer the fashion. 

 The Dunes, extending along the coast of Gascony 

 from the Adour to the Gironde, form a belt four to 

 eight kilometres wide. Their sand does not come 

 from the coasts of Spain and Brittany, as has been 

 supposed, but from a submerged continuation of 

 the Landes. Their height sometimes reaches eighty 

 metres. These, also, were formerly barren : they are 

 now almost entirely wooded over. Their area of 

 88,096 hectares (nearly 350 □ miles) contained 15,82 



