Hofmann is as follows: the mixture is distilled with caustic potash, when the primary, secondary and tertiary amines distil over, and the quaternary ammonium salt remains behind unaffected.
That a subsequent land connexion took place, however, by the elevation of the sea-bed there is abundant evidence to show; and the occurrence of the remains of African Quaternary mammals, such as Elephas meridionalis, E.
The greater part of Tunisia is composed of sandstones, marls and loosely stratified deposits belonging to the Pliocene and Quaternary periods.
Among the Tertiary volcanic rocks those of acid types (granites, granulites) were the first to appear and are developed latitudinally; rocks of intermediate type (dacites, andesites) characterize the Miocene and early Pliocene periods; while the basic rocks (ophites, elaeolite syenites and basalts) attained their maximum in later Pliocene and Quaternary times.
The Quaternary beds of lakes Bonneville and Lahontan have been faulted in a small way since they were deposited, and the old shore lines of these lakes have been deformed to the extent of hundreds of feet.
The earlier geologists had been in the habit of dividing the Quaternary deposits into an older Diluvium and a younger Alluvium; the latter is still employed in England, but the former has dropped out of use, though it is still retained by some continental writers.
The geological formation of the soil belongs to the Quaternary and Pliocene period in its upper strata, and to the Eocene and Cretaceous in the lower.
In the west the Quaternary deposits are not, in all cases, sharply separated from the late Tertiary, but the deposits of glacial drift, referable to two or more glacial epochs, are readily differentiated from the Tertiary; so, also, are certain lacustrine deposits, such as those of the extinct lakes Bonneville and Lahontan.
The second Quaternary formation is the Port Hudson, occurring within 20 m.
Here in 1856 were discovered in a Quaternary bed in the Feldhofen Cave human remains which have been referred to a type commonly called Neanderthal Man.