Abstracts of Foreign Memoirs. 165 
quantity. Some contain hardly any appreciable residue, others more 
than 100 grammes a litre (nearly 20 ounces a gallon). By chemical 
investigation, and above all by spectral analysis, they have already 
been found to contain all the metalloid elements except selenium 
and tellurium, and 21 of the metallic elements. The quantity of 
solid matter brought to the surface by the mineral springs of the 
central plateau of France in one year is upwards of 8,000 tons. 
Of the gases contained in mineral waters, two (oxygen and hydro- 
gen) are the constituents of water. Both are common; but neither 
of them occurs in a simple state. Nitrogen is also very common. 
M. Lecog is inclined to refer the origin of these to the distant epoch 
when, as he believes, the springs were much more abundant than they 
noware. Ammoniaand carbonic acid are both present, separately and 
combined. Sulphur and sulphurous acid, often combined with hydro- 
gen, are also common. ‘These sulphurous combinations are believed 
to have an organic origin, but they are referred, as usual, by our 
author to his great subterranean laboratories beneath the zone of 
primitive rocks, where, as he_believes, the water is mineralized. 
Tellurium, chlorine, iodine, chromium, fluorine, phosphorus and ar- 
senic, either native or incombination, are next specified, and examples 
of their presence given. Most of them are common. Boron (boracic 
acid) is also familiar; and silicon is universal. The phenomena 
accompanying the presence and deposit of silica are carefully 
described, and the same remark applies to carbon and carbonic acid. 
Most of the facts have been previously recorded; but they are here 
conveniently grouped, and the theoretical views of the author are 
again brought in. He believes that the first important (?) introduc- 
tion of carbonic acid dates from the deposit of the Carboniferous 
Limestone (p. 123). The term grauwacké, now almost extinct, serves 
to include the whole of the vast Devonian, Silurian, and Laurentian 
series ; and in these limestones are practically ignored by our author. 
In a subsequent chapter bitumens are considered. With these and 
other hydro-carbons, M. Lecoq seems chiefly familiar so far as his 
own district of Central France is concerned ; but he gives an outline- 
account of the discovery of oil-wells in America, and their develop- 
ment up to 1861.* Like other substances rising from the earth in 
springs, bitumens are here referred, not to an organic source, but to 
the great depths of the earth for their origin. 
Potassium, lithium, rubidium, cesium, thallium, glucina, have all 
been obtained either from mineral waters, or from positions that render 
their presence in such waters almost certain. Potassium is very 
common; the others, until lately, were rare or unknown. Lithium 
is now very generally recognized by the aid of spectrum-analysis 
Many of the salts of sodium, besides the chloride (common salt), are 
met with. They are among the substances most generally distri- 
buted in water, both on and beneath the surface. The carbon- 
ate, nitrate, and sulphate of soda are those chiefly noticed. The 
* The exports from American ports now amount to about twenty million gallons 
annually. 
