80 Reviews — Ilccr’s Primceval World of Switzerland. 
Prof. Heer describes and figures many of those beautiful Carboni- 
ferous plant-reraains coated as it were with silver or gold, met witb 
in the Valais and higher up in the Col de Bahne. These plants have 
also been found at the Col d’Anterne above Chamouni, and were 
examined in 1856, by Mr. Alfred Wills, whose collection is pre- 
served in the British Museum. One remarkable feature to be seen 
at the village of Petit Coeur, near Moutiers in the Tarentaise (due to 
the inversion of the Carboniferous strata), was noticed by Elie de 
Beaumont in the ‘ Annales des Sciences Naturelles ’ so long ago as 
1828. 1 Here we find Belemnites in Secondary rocks beneath shales 
of undoubted Carboniferous age. 2 
From the formation of Coal, Prof. Heer proceeds to speak of that 
most nearly analogous accumulation of vegetable fuel — Peat, which 
we may observe going on at the present day over such extensive 
tracts in the colder temperate regious of the earth, and from which, 
in Denmai'k, Ireland, Switzerland, and some parts of England also, 
such interesting relics of prehistoric man have been obtained. 
Unfortunately for Switzerland. her industrious andpatriotic people 
enjoybut a very small share of that valuable Coal-formation so widely 
distributed through England, Belgium, and the United States. Con- 
sequently peat and wood fuel are carefully collected and stored, and 
for coal its industries depend upon the basins of Saarbrück and St.- 
Etienne and a smaller quantity from the Vosges (Bonchamp), and from 
the Kuhr district in Westphalia. The rate of growth of peat is no doubt 
subject to considerable climatal variations, being readily influenced 
both by the temperature and moisture of the atmosphere. Prof. 
Heer says that — “ Under moderately favourable circumstances, 1 foot 
of peat may be produced in a Century. In the form of coal this 
would make a layer of 0 - 33 line, or about ^rd of a line. To produce 
a bed of coal 44 feet in thickness, such as occurs in England, a 
period of nearly 20,000 years would therefore be necessary. If we 
take the increase at 3 lines annually, 10,000 years would be required, 
or with 4 times the increase, only 5,000 years.” 
Even under tbe most favourable conditions for rapid increase, 
however, the period of time involved in the annual growth, decay 
and accumulation of Vegetation and its conversion into coal, must 
necessarily have been immense. In South Wales, for instance, the 
total thickness of the Coal-measures lias been reckoned at from 
10,000 to 12,000 feet. Estimating the increase of sediment at 2 feet 
in a Century, and admitting, with Mr. C. Maclaren, that itmight take 
1000 years to form a bed of coal 1 yard in thickness, Prof. Hüll has 
calculated that the deposits forming the South Wales Coal-field 
might have been accumulated in 640,000 years ! 3 
1 See also Sir C. F. Bunbury’s paper on Fossil Plants from the Anthracite 
Formation of the Alps of Savoy, Quart. Journ. Geol. Soe. Lond., 1849, vol. v. 
p. 130. 
2 See Prof. Favre’ s Geological Researches in the Vicinity of Mont Blanc in Savoy, 
Piedmont, and Switzerland, vol. iii. p. 337, etc. 
3 See “ The Geology of England and Wales,” by Horace B. Woodward, F.G.S., 
1876, p. 93. 
