degree in which the mucous membrane contains the dimorphous cellgrowth. Of those alternatives respecting the gastric juice suggested by various experiments,—namely, (1) the secretion of pepsine by the dimorphous cell-growth, and acid by the columnar; or (2) the perfecting of the secretion (itself perhaps owing these two constituents to its two kinds of cell respectively) in the open ends only of these tubes,-the latter is, on the whole, preferable. The protection of the stomach from its own secretion is effected mainly by the salivary and other secretions which enter it from the oesophagus and duodenum. The living stomach decomposes a neutral or alkaline blood, so as to set free an acid; but though transfused blood undergoes this decomposition, a saline solution not only fails to evoke it, but injures or destroys the gastric powers. There is no evidence of any exhaustion of the pepsinous constituents of the gastric mucous membrane at any period of digestion. As regards other variations of power, age seems to exercise but a moderate influence on the gastric mucous membrane; species, again, has a subordinate effect; genus is much more influential. For units of mucous membrane, fishes seem to have the most powerful gastric digestion. The influences of temperature, analogous in all animals, vary exceedingly as regards the absolute heats which respectively favour, accelerate, and destroy the powers of the stomach; so that the same heat which is practically necessary for the function of this organ in a warm-blooded mammal, annihilates the efficacy of the pepsine of many fishes. The action of the gastric juice is a transfer to albumen, &c., of a molecular change going on in the gastric juice-pepsine and peptone being essentially analogous to each other in properties. The formation of peptone is a hydration of albumen, as shown by various collateral circumstances of the process.

Addenda.-1. The pancreatic juice, or pancreatic infusion, which converts albumen into a substance akin to peptone, and in proportions not very unlike those which would be obtainable by using certain parts of the mucous membrane of the stomach of some animals, and which does this by a process so far sui generis as that it is no way shared by the salivary organs most analogous to itself in structure and function, is yet distinguishable from the gastric juice in regard to the process and the product of this change. The change is, indeed, an incident of putrefaction only, and therefore not a function of the healthy living organ. 2. The intestinal juice, or the secretion of the intestinal tubes, is neither capable of converting albumen, &c., into peptone, nor of converting starch into sugar. The offices of these tubes are therefore, probably, chiefly of absorption and of excretion.-Proceedings of the Royal Society.

PUBLICATIONS RECEIVED.

Quarterly Journal of the Chemical Society for October 1861.-From the Society.

Manual of the Sub-kingdom Coelenterata. By Professor JOSEPH R. GREENE. From the Author.

Journal of the Asiatic Society of Bengal, No. II., for 1861.-From the Secretaries.

Practical Treatise on the Use of the Ophthalmoscope. By J. W. HULKE, F.R.C.S-From the Publisher.

Proceedings of the Literary and Philosophical Society of Manchester, Nos. III. to VI., Session 1861-62.-From the Society.

Proceedings of the Academy of Natural Sciences of Philadelphia, 1861. Pp. 65 to 144.- From the Society.

Scripture and Science not at Variance. By Archdeacon PRATT.-From the Publisher.

Dublin Quarterly Journal of Science, No. IV., October 1861.-From the Editor.

From the Publisher.

Metallurgy. By JOHN PERCY, M.D. Annales de l'Agriculture des Colonies (Algerie) et des Regions Tropicales. Par N. PAUL MADINIER. Nos. VII. and VIII., for 1861.—

From the Author.

Astronomical Observations in the Arctic Seas. By Dr E. K. KANE.— From the Smithsonian Institution.

Meteorological Observations made near Washington, Arkansas. By NATHAN D. SMITH, M.D.-From the Smithsonian Institution.

Meteorological Observations made in Providence, R.I. By Professor ALEXIS CASWELL.-From the Smithsonian Institution.

Tidal Observations in the Arctic Seas. By Dr E. K. KANE.—From the Smithsonian Institution.

Report on the Chemical Analysis of the White Sulphur Water of the Artesian Well of Lafayette, Ind. By Dr CHARLES M. WETHERELL From the Author.

General Outline of the Organisation of the Animal Kingdom, and Manual of Comparative Anatomy. By THOMAS RYMER JONES, F.R.S. Third Edition.-From the Publisher.

Researches upon the Venom of the Rattlesnake, with an Investigation of the Anatomy and Physiology of the Organs concerned. By S. WEIR MITCHELL, M.D., Lecturer on Physiology in the Philadelphia Medical Association.-From the Author.

Second Report of a Geological Reconnoissance of the Southern and Middle Counties of Arkansas, made during the years 1859 and 1860.— From D. D. Owen, Principal Geologist.

THE

EDINBURGH NEW

PHILOSOPHICAL JOURNAL.

On the Climate of Palestine in Modern compared to Ancient Times. By JAMES D. FORBES, D.C.L., LL.D., V.P.R.S.E., Principal of the United College of St Salvator and St Leonard, St Andrews.*

Since thermometric observations extend back for only about two hundred years, and even these are very limited, and often of questionable precision, we are compelled to rely, in any comparison between ancient and modern climates, upon authentic records of phenomena depending upon heat and cold, which are also capable of being definitely described.

Such are instances of the freezing during winter of considerable rivers and other bodies of water, the periods of harvest of different crops, and generally the limitation of the growth of certain species of plants by conditions of climate.

The first of these tests, though not unworthy of notice, is not only somewhat vague, but depends upon the recurrence of seasons of extraordinary and not ordinary severity, which we know to be amongst the most uncertain and capricious of meteorological data.

The significance of the two last tests-the date of harvest, and the growth of certain critical plants in certain localities— was ably pointed out by the eminent Danish botanist Schouw of Copenhagen. These tests form the chief arguments of his able paper on supposed changes of climate. I am only acquainted with the first portion of this paper, as published in the

* Read before the Royal Society of Edinburgh, 6th January 1862. NEW SERIES.-VOL. XV. NO. II.-APRIL 1862.

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66

Edinburgh Journal of Science" for 1828.* Whether the original has ever been published in full in the Danish Transactions or elsewhere, I am unable to state.

The most striking part of this interesting fragment refers to the climate of Ancient compared to that of Modern Palestine, for the discussion of which we possess data at once more extensive and applicable to a more remote epoch than can be jointly furnished by the records of any other country. Having recently had occasion to redirect my attention to Schouw's argument, and having had leisure to verify it by a reference to the researches of the last thirty years, I have thought it well to record the conclusions to which I have come, on subject of some popular as well as scientific interest.

Passing over for the present the argument in favour of the conclusion that the climate of Palestine has not sensibly changed since the days of Moses, derived from the fact that the wheat harvest and vintage still occur at the periods of the year fixed with sufficient definiteness in the Old Testament, we will take up Schouw's striking and ingenious argument derived from the simultaneous cultivation in Judea of the vine and the date-bearing palm.

The argument is briefly as follows:-The date-palm (Phoenix dactylifera) was in ancient times abundant in many parts of Palestine, where its fruit ripened. This we learn from both sacred and profane authors, and also from Roman coins. On the other hand the vine (Vitis vinifera) was notoriously an abundant product of the same country, where it attained extraordinary perfection, and was in habitual and extensive use for the manufacture of wine. Now, the botanical inquiries of Schouw led him to conclude, that the date tree requires for perfect fertility a mean temperature of the year not under 21° Centigrade, or 69° 8 of Fahrenheit. The mean temperature therefore of those parts of Palestine where the date was historically abundant, could not anciently have fallen below 70° (in round numbers). But the vine does not endure a tropical climate. According to Von Buch, quoted by Schouw, it ceases to flourish productively in the Canary Isles,

* Vol. viii. p. 311.

Algiers, and Egypt, wherever the mean temperature of the year approaches 22° Centigrade, or 71°6 Fahrenheit. The co-existence of these two plants in a fruitful condition shuts us up to the conclusion, according to this author, that the mean temperature must have anciently been intermediate between 70° and 72°. In the absence of direct observations of the temperature of Jerusalem, he infers, from the ascertained modern temperature of Cairo and other places, that Jerusalem has probably 70° of mean temperature. "If, therefore," he adds, "there has been any difference at all between the mean temperature of Jerusalem in ancient and modern times, it can hardly amount to one degree (Centigrade), a difference similar to that between Copenhagen and Berlin."*

It might have been expected that Arago, when availing himself much more recently of the arguments of Schouw on this subject, would have thrown the farther light upon them which the improvement of meteorology and botanical geography, as well as the local researches of modern travellers, might have afforded. He has, however, contented himself with translating, almost literally, the memoir of the Danish botanist.†

On reconsidering carefully the evidence for the permanence of the climate of Palestine, as given by Schouw, it appeared to me that it was open to doubt on the following grounds:—(1.) That no consideration is given to the well-known facts, that Jerusalem is placed at a great elevation (2200 feet) above the level of the Mediterranean, and that Palestine is altogether a mountainous country, and therefore includes a considerable variety of climates respectively suited to different classes of plants. The importance of this consideration is such as to invalidate the otherwise ingenious reasoning of the Danish botanist. (2.) That Schouw confined his attention to mean

* Edinburgh Journal of Science, viii. 316. In confirmation of his argument Schouw adds, "The frequent cultivation of wheat in Palestine proves that its temperature cannot have been above 24° or 25° (Cent.) The growth of the balsam tree, near Jericho, proves that it has not been below 21° or 22°; and among all other determinable plants and animals of Ancient Palestine, the author could not find a single one which was contrary to the assumed mean temperature of 21°."

↑ Arago,“ Œuvres," viii. p. 215. Compare "Annuaire, &c., pour 1834," p. 204.