added to his numerous contributions to anesthesia the use of the ether spray. In 1864 a committee of the Royal Medical and Chirurgical Society recommended the mixture of alcohol, chloroform, and ether first used by Harley. In the years following 1863 the use of nitrous oxide, which had been allowed to lapse after the death of Horace Wells in 1848, was greatly stimulated through the advocacy of Colton both in America and Europe; and in 1868 Edmund Andrews proved that the anesthetic effects of nitrous oxide do not depend on partial asphyxiation. He thus cleared up a misconception of long standing. His mixture of oxygen and nitrous oxide gave very satisfactory results.

REFERENCES

Bigelow, Henry J.: Surgical Anesthesia. Addresses and Other Papers. 1900.

Gordon, Laing: Sir James Simpson (Masters of Medicine). 1898. 233 pp.

Gwathmey, J. T. (in collaboration with Charles Baskerville): Anesthesia. 1914. 943 PP.

Kelly, H. A.: "Hypnotism," Maryland Medical Journal, vol. LIII, 1910, pp. 81-97.

Paget, Sir James: "Escape from Pain; the History of a Discovery," The Nineteenth Century, vol. 6, 1879, pp. 1119–32. Rice, Nathan P.: Trials of a Public Benefactor. 1859. 460 pp. Young, Hugh H.: Long, the Discoverer of Anesthesia, Johns Hopkins Hospital Bulletin, vol. VIII, 1897, pp. 174-84.

CHAPTER XV

THE THEORY OF ORGANIC EVOLUTION

WHEN Charles Darwin, in October, 1836, returned to England from his voyage round the world, which had occupied nearly five years, he had arrived at no theory concerning the origin of species. In 1837, however, he made the following note: "In July opened first note-book on Transmutation of Species. Had been greatly struck from about the month of previous March on character of South American fossils, and species on Galapagos Archipelago. These facts (especially latter) origin of all my views." In the months intervening between October, 1836, and July, 1837, he had been thrown into close contact with the great geologist Sir Charles Lyell, the champion of the uniformitarian doctrine.

This doctrine, that the changes that have taken place in the earth's crust in the past were owing to agencies still in operation, had been splendidly stated by the Scotch geologist James Hutton in 1785. Hutton's views, however, had been ignored by some scientists, and decried by others because of their alleged anti-religious tendency. The hostility to Hutton's teaching in 1822 was thus expressed by one of the leading English geologists, who was will

ing to concede some recognition to the facts gathered by the Scotch geologist in reference to granite and other rocks: "The wildness of his theoretical views, however, went far to counterbalance the utility of the additional facts which he collected from observation. He who could perceive in geology nothing but the ordinary operation of actual causes, carried on in the same manner through infinite ages, without the trace of a beginning or the prospect of an end, must have surveyed them through the medium of a preconceived hypothesis alone." Professor Sedgwick, under whom Darwin had studied geology at Cambridge, in a similar vein eloquently denounced the unscriptural tenets of Hutton and Hutton's disciples. Both Sedgwick and Henslow, the botanist, Darwin's chief masters at Cambridge, were clergymen, and Darwin, till the time of his appointment as naturalist to the Beagle expedition, planned to take orders ultimately in the Established Church of England.

Sir Charles Lyell (1797-1875) had been an early convert to the uniformitarian view, but fully conscious of the strength of the opposition, and naturally kindly and sympathetic as regards the opinions of his intellectual inferiors, his public utterances were of the most tactful sort. A careful study of Gibbon had convinced him that the frontal attack is not the most effective method of combating re

ligious prejudice, and had helped him to develop further a pleasing style of composition, which an early acquaintance with the classics and the constant example of a father of scholarly tastes had already made second nature. At the age of twenty he observed on the coast of East Anglia the action of the sea in the formation of new land as well as in the wearing down of the cliffs; and in the following years he found abundant evidence in his native Forfarshire, in the action of rain and rivers and the formation of limestone, that all observable changes in the earth's crust were not owing to the Noachian deluge.

By 1825 Lyell was a convinced uniformitarian, and was considering how he could express his convictions without rousing unnecessary opposition and without giving offence to his older contemporaries. In 1827 he had completed the first sketch of his Principles of Geology, and two years later, in preparing the book for the press, he made a preliminary statement, in a letter to a friend, of his doctrine "that no causes whatever have from the earliest time to which we can look back to the present, ever acted, but those that are now acting, and that they never acted with different degrees of energy from that which they now exert." The first volume appeared in 1830 with the subtitle "An Attempt to Explain the Former Changes of the

Earth's Surface by Reference to Causes now in Operation." Lyell was not oblivious to the logical outcome of applying the uniformitarian doctrine to the study of the organic world, and when Sedgwick and others charged him with holding that the creation of new species is going on at the present day he readily admitted it. He thought it impossible that any one should read his work without perceiving that the notion of uniformity in the existing causes of change implies that "they must for ever produce an endless variety of effects, both in the animate and inanimate world."

When Darwin was leaving England in 1831 the extremely orthodox Henslow advised him to take Lyell's first volume with him, but to pay no attention to it, except in regard to facts, for it was altogether wild as far as theory goes. Needless to say it made a very deep impression on the mind of the young naturalist. Lyell's second volume appeared in 1832, and a copy of it was sent to Darwin at Montevideo. This second volume was full of facts concerning variations, hybridism, and the struggle for existence; and it no doubt had a great effect on Darwin's subsequent observations and on his maturer generalizations. In fact, in dedicating the second edition of "A Naturalist's Voyage" to Lyell the author with characteristic generosity writes: "This edition is dedicated with grateful pleasure as