Encyclopaedia Britannica, 11th Edition, 'L' to 'Lamellibranchia' / Volume 16, Slice 1 - Various

	Total Solids by Evaporation expressed in Grams per Litre.
Great Salt Lake (Russell)	238.12
Lake of Geneva (Delebecque)	0.1775

The following analysis of a sample of the water of the Great Salt Lake (Utah, U.S.A.) is given by I. C. Russell:—

	Grams per Litre.		Probable Combination.
Na	75.825	NaCl	192.860
K	3.925	K2SO4	8.756
Li	0.021	Li2SO4	0.166
Mg	4.844	MgCl2	15.044
Ca	2.424	MgSO4	5.216
Cl	128.278	CaSO4	8.240
SO3	12.522	Fe2O3 + Al2O3	0.004
O in sulphate	2.494	SiO2	0.018
Fe2O3 + Al2O3	0.004	Surplus SO3	0.051
SiO2	0.018
Bo2O3	trace
Br3	faint trace

The following analyses of the waters of other salt lakes are given by Mr J. Y. Buchanan (Art. “Lake,” Ency. Brit., 9th Ed.), an analysis of sea-water from the Suez Canal being added for comparison:—

	Koko-nor.	Aral Sea	Caspian Sea.		Urmia Sea.	Dead Sea.	Lake Van.	Suez Canal, Ismailia.
	Koko-nor.	Aral Sea	Open.	Karabugas.	Urmia Sea.	Dead Sea.	Lake Van.	Suez Canal, Ismailia.
Specific Gravity	1.00907	..	1.01106	1.26217	1.17500	..	1.01800	1.03898
Percentage of Salt	1.11	1.09	1.30	28.5	22.28	22.13	1.73	5.1
Name of Salt.	Grams of Salt per 1000 Grams of Water.
Bicarbonate of Lime	0.6804	0.2185	0.1123	..	..	..	..	0.0072
Bicarbonate of Iron	0.0053	..	0.0014	..	..	..	..	0.0069
Bicarbonate of Magnesia	0.6598	..	..	..	..	..	0.4031	..
Carbonate of Soda	..	..	..	..	..	..	5.3976	..
Phosphate of Lime	0.0028	..	0.0021	..	..	..	5.3976	0.0029
Sulphate of Lime	..	1.3499	0.9004	..	0.7570	0.8600	..	1.8593
Sulphate of Magnesia	0.9324	2.9799	3.0855	61.9350	13.5460	..	0.2592	3.2231
Sulphate of Soda	1.7241	..	..	..	..	..	2.5673	..
Sulphate of Potash	..	..	..	..	..	..	0.5363	..
Chloride of Sodium	6.9008	6.2356	8.1163	83.2840	192.4100	76.5000	8.0500	40.4336
Chloride of Potassium	0.2209	0.1145	0.1339	9.9560	..	23.3000	..	0.6231
Chloride of Rubidium	0.0055	..	0.0034	0.2510	..	..	..	0.0265
Chloride of Magnesium	..	0.0003	0.6115	129.3770	15.4610	95.6000	..	4.7632
Chloride of Calcium	..	..	..	..	0.5990	22.4500	..	..
Bromide of Magnesium	0.0045	..	0.0081	0.1930	..	2.3100	..	0.0779
Silica	0.0098	..	0.0024	..	..	0.2400	0.0761	0.0027
Total Solid Matter	11.1463	10.8987	12.9773	284.9960	222.2600	221.2600	17.2899	51.0264

This table embraces examples of several types of salt lakes. In the Koko-nor, Aral and open Caspian Seas we have examples of the moderately salt, non-saturated waters. In the Karabugas, a branch gulf of the Caspian, Urmia and the Dead Seas we have examples of saturated waters containing principally chlorides. Lake Van is an example of the alkaline seas which also occur in Egypt, Hungary and other countries. Their peculiarity consists in the quantity of carbonate of soda dissolved in their waters, which is collected by the inhabitants for domestic and commercial purposes.

The following analyses by Dr Bourcart give an idea of the chemical composition of the water of fresh-water lakes in grams per litre:—

	Tanay.	Bleu.	Märjelen.	St Gothard.
SiO2	0.003	0.0042	0.0014	0.0008
Fe2O3 + Al2O3	0.0012	0.0006	0.0008	trace
NaCl	0.0017	..	..	..
Na2SO4	0.0011	0.0038	0.0031	0.00085
Na2CO3	..	..	..	0.00128
K2SO4	0.0021	0.0028	0.0044	..
K2CO3	..	..	0.0003	0.00130
MgSO4	0.006	0.0305	..	..
MgCO3	0.0046	0.0158	0.0008	0.00015
CaSO4	..	..	..	..
CaCO3	0.107	0.1189	0.0061	0.00178
MnO	0.001	..	..	..

(b) Movements and Temperature of Lake-Waters.—(1) In addition to the rise and fall of the surface-level of lakes due to rainfall and evaporation, there is a transference of water due to the action of wind which results in raising the level at the end to which the wind is blowing. In addition to the well-known progressive waves there are also stationary waves or “seiches” which are less apparent. A seiche is a standing oscillation of a lake, usually in the direction of the longest diameter, but occasionally transverse. In a motion of this kind every particle of the water of the lake oscillates synchronously with every other, the periods and phases being the same for all, and the orbits similar but of different dimensions and not similarly situated. Seiches were first discovered in 1730 by Fatio de Duillier, a well-known Swiss engineer, and were first systematically studied by Professor Forel in the Lake of Geneva. Large numbers of observations have been made by various observers in lakes in many parts of the world. Henry observed a fifteen-hour seiche in Lake Erie, which is 396 kilometres in length, and Endros recorded a seiche of fourteen seconds in a small pond only 111 metres in length. Although these waves cause periodical rising and falling of the water-level, they are generally inconspicuous, and can only be recorded by a registering apparatus, a limnograph. Standard work has been done in the study of seiches by the Lake Survey of Scotland under the immediate direction of Professor Chrystal, who has given much attention to the hydrodynamical theories of the phenomenon. Seiches are probably due to several factors acting together or separately, such as sudden variations of atmospheric pressure, changes in the strength or direction of the wind. Explanations such as lunar attraction and earthquakes have been shown to be untenable as a general cause of seiches.