an examination of the deposit of clays, etc., at the bottom of the lake, these deposits being in various places eroded by the action of rivers since the last flooding of the lake. These deposits consist, speaking roughly, of three distinct layers, viz I.-Upper Lacustral Clays, containing a large number of freshwater shells and bones of mastodon or elephant, horse and camel; depth from 50 to 75 feet. II.-Medial Gravels, containing fossil shells and having a depth varying between 50 and 200 feet. III.- Lower Lacustral Clays, full depth not exposed but set down at 100 feet; contain only one fossil species, Pompholyx effusa, which is also found in the upper strata, and is still living in the district.

Lake Lahontan never overflowed. A geologist, therefore, taking note of this, and of the nature of the soil and rocks over and through which the rivers of the district have flowed ever since the land received its present configuration, would expect to find immense saline deposits, the salts being thrown down in the following order, as the waters evaporated: I.-Calcium carbonate; II.-Calcium sulphate; III.-Sodium sulphate; IV.-Sodium carbonate; V.Sodium Chloride; and other more deliquescent salts after these. He would also expect to find any existing lakes or pools to contain a dense "mother-liquor," rich in magnesia, potash, and soda, and some of the less common substances, such as lithium, boracic acid, etc. But, on examining Lake Lahontan, neither of these expectations is borne out. There are immense deposits of calcium carbonate, but not of any other of the salts named; and the water bodies now extant in the old lake-bed do not contain one half per cent. of total solids in solution. The calcium carbonate is deposited in three forms, marking three epochs in the lake-history; these are, in their order of deposition, the lithoid tufa, the thinolitic tufa, and the dendritic tufa. These are deposited on

the older rocks, and upon each other, frequently forming a sheathing of fifty or sixty feet in thickness, and sometimes assuming the form of domes and castellated masses, which rise a hundred feet above the nuclei round which they were first crystallised. The lithoid tufa is described as being compact and stony in structure, light yellowish gray in colour, and as weathering into forms of extreme ruggedness. On cliffs and "buttes" it seems to be composed of comblike masses, imbricated in such a manner as to resemble a massive thatch. It is found from the lowest depths to within thirty feet of the highest water line in the basin, and in the upper regions is from 8 to 10 inches thick, lower down it reaches a thickness of 10 or 12 feet, but as the base is generally hidden by other deposits, its maximum thickness cannot be given. The next in order is the thinolite, a deposit of interlaced crystals of calcium carbonate. The colour varies from gray to brown, and the crystals are usually from a quarter of an inch to an inch in diameter, and up to 8 or 10 inches in length. This deposit is found only below the terrace situate one hundred and ten feet above the level of Pyramid Lake. In some places it occurs in alternate bands with the third variety of tufa, which, from its frequent assumption of arborescent forms, Mr. Russell calls the dendritic. From its reaching a higher level than the thinolite, it is concluded that it was deposited from a more diluted solution; if this be a correct reading, then the alternate layers are the record of successive shrinkings and floodings of the lake. Evenly stratified lacustral beds containing shells of fresh water molluscs above the layer of dendritic tufa, shew that, after depositing the tufa, the lake rose again and was essentially fresh.

This freshening of the waters of a lake after a long accumulation of salts is explained by the following theory: "A lake, after a long period of concentration, becomes

strongly saline, and finally evaporates to dryness, leaving a deposit of various salts over its bed. During the rainy season, the bottom of the basin is converted into a shallow lake of brine which deposits a layer of [earthy] sediment. On evaporating to dryness during the succeeding arid season, a stratum of salt is deposited which is, in its turn, covered by sediment. This process taking place year after year results in the formation of a stratified deposit, consisting of salts and saline clays in alternate layers. The saline deposits may thus become more and more earthy, until the entire annual accumulation consists of clays. The site of the former lake thus becomes a playa. A return of humid conditions would refill a basin of this character, and might form a fresh-water lake, the bottom of which would be the level surface of the submerged playa." (p. 224).

Mr. Russell states that every stage of this process may be seen in various lakes of the far West, and at Ragtown there is a manufacture of soda where an excavation, twenty-five feet in depth, into the bottoms of a small basin with an ordinary playa in it shewed that the material below the surface consisted of layers of soda-salts separated by strata of dust and mud. And in summer-when every drop of moisture from these playa deserts evaporates-there appears a white saline efflorescence, which sometimes covers miles of country with an incrustation frequently five or six inches in thickness, and as dazzling as snow. In addition to the soda-works just mentioned, there are salt-works in several spots in the basin whose output is regulated entirely by the demand. At one

of these there is a field of salt varying in depth from a few inches to three feet, and the whole process of manufacture consists in shovelling the salt into barrows, and piling it in situations more convenient for removal.

As will no doubt be anticipated, the population is sparse in this region, water is scarce, and agriculture difficult; the

few settlements that there are lie mainly along or near the Central Pacific Railway, which traverses one of the longest reaches of the ancient lake bed from N.E. to S.W. From the descriptions, however, and pictures-both excellent in their way-contained in the very interesting monograph of which this paper is a very inadequate summary, it is clear that, to the well-to-do traveller in search of something new, Lake Lahontan offers great attractions. I forgot to state that Mr. R. considers that the present state of things in the Lahontan basin cannot be more than three hundred years old.

345

IS THOUGHT POSSIBLE WITHOUT WORDS? A DISCUSSION ON MAX MÜLLER AND DARWIN.*

BY JOHN NEWTON, M.R.C.S.

I ESTEEM myself fortunate in being able to bring before you a subject of the deepest interest to all, and to the discussion of which everyone will be able to contribute something from his own experience. Professor Max Müller, one of the most distinguished scholars and brilliant writers of our time, has lately given to the world a large and profoundly interesting volume called, The Science of Thought, on the title-page of which is prominently displayed the text of his discourse, that discovery which is to revolutionise the science of thought, and reduce all to a mere study of the science of language. It is comprised in these few words :-" No Reason without Language; No Language without Reason."

At the outset, he proceeds to define his terms: "I mean by thought the act of thinking, and by thinking I mean no more than combining. I think means to me the same as the Latin cogito (namely, co-agito, I bring together), only, with the proviso, that bringing together, or combining, implies separating; for we cannot combine two or many things without, at the same time, separating them from all the rest. Hobbes expressed the same truth, long ago, when he said that all our thinking consisted in addition and subtraction." By language we mean what the Greeks called logos, word and meaning in one" (p. 29); that is, human speech, words, and nothing else. Thus, he says, that "we cannot think without words," nor "make even the first step in

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*The Science of Thought, by F. Max Müller. 1 vol. 8vo, pp. xxiv and 664. London, 1887.