The next year, 1824, Lyell made a geological tour with M. Constant Prévost, a noted French geologist, from London to Bristol and Land's End, and with Dr. Buckland, in Scotland, where they dined with the far-famed Francis Jeffrey, editor of the "Edinburgh Review." Lyell's eyes still troubled him so that he could scarcely write letters home; but he was laying up a store of knowledge from which the world was to profit in a few years.
In 1825, his eyes having improved, he resumed his law study, and was admitted to the bar. But he could not give up geological work, and published several papers,—one on a dike of serpentine, another on shell marl and fossil fruit, and others on plastic clay in Hampshire and the fresh-water strata of Hants. He had been made a Fellow of the Royal Society at twenty-nine, and was one of the writers in the "Quarterly Review."
The law work went on, but it was easy to see where his heart was. He wrote a friend that he had been "devouring" Lamarck: "That the earth is quite as old as he supposes has long been my creed, and I will try before six months are over to convert the readers of the 'Quarterly' to that heterodox opinion.... Buckland has got a letter from India about modern hyænas, whose manners, habitations, diet, etc., are everything he could wish, and as much as could be expected had they attended regularly three courses of his lectures."
At thirty-one Lyell had made up his mind "that there is most real independence in that class of society who, possessing moderate means, are engaged in literary and scientific hobbies;" he had given up the law, and planned the book that was to make him famous—"Principles of Geology." He travelled now extensively in Italy and France, studying volcanoes, glaciers, and fossils. At Auvergne, he began work with his dear friend Murchison at six o'clock in the morning, "and neither heat nor fatigue has stopped us an hour," he writes to his parents. "I have really gained strength so much, that I believe that I and my eyes were never in such a condition before; and I am sure that six hours in bed, which is all we allow, and exercise all day long for the body, and geology for the mind, ... is the best thing that can be invented in this world for my health and happiness."
Eighteen hours of labor daily, and yet he was happy! He had found his life-work now. To a sister he writes about the beetles at Aix. He cannot be laughed out of this study as when a boy. He has been to Parma, to see Professor Guidotti's "finest collection of fossil-shells in Italy, ... spending three days, from six o'clock in the morning till night, exchanging our respective commodities."
To his sisters he writes all his discoveries in rocks and fossils, with the enthusiasm of a boy. "I rode to the upper Val d'Arno,—a famous day for me,—an old lacustrine deposit, corresponding delightfully with our Angus lakes in all but age and species of animals; same genera of shells. They have just extracted the fortieth skeleton of hippopotamus; have got about twenty elephants, one or two mastodons, a rhinoceros and stags, and oxen out of number.... At Rome I found the geology of the city itself exceedingly interesting. The celebrated seven hills, of which you have read, and which in fact are nine, are caused by the Tiber and some tributaries, which have cut open valleys almost entirely through volcanic ejected matter, covered by travertine containing lacustrine shells."
He made the ascent of Etna, and sketched the crater. "Inside the crater, near the lip, were huge masses of ice, between which and the scoriæ and lava of the crater issued hot sulphurous vapors, which I breathed in copiously; and for six hours after I could not, even after eating and drinking, get the horrid taste out of my mouth, for my lungs had got full of it. The wind was so high, that the guide held my hat while I drew; but though the head was cold, my feet got so hot in the cinders, that I was often alarmed that my boots would be burnt."
In 1830, the first volume of "Principles of Geology, being an Attempt to Explain the Former Changes of the Earth's Surface by Reference to Causes now in Operation," was published. "It will not pretend," he wrote to Murchison, "to give even an abstract of all that is known in geology, but it will endeavor to establish the principles of reasoning in the science; and all my geology will come in as illustration of my views of those principles, and as evidence strengthening the system necessarily arising out of the admission of such principles, which, as you know, are neither more nor less than that no causes whatever have from the earliest time to which we can look back, to the present, ever acted, but those now acting.... I must go to Germany.... Their language must be learnt; the places to which their memoirs relate, visited; and then you may see, as I may, to what extent we may indulge dreams of eminence, at least as original observers." He, too, like all the other great ones, indulged in "dreams of eminence." Did ever man or woman achieve anything worthy without these dreams?
He had worked earnestly upon the "Principles," which showed wonderful research, study, and thought. He said, "The facts which are given in a few sentences require weeks of reading to obtain.... By the aid of a good amanuensis, my eyes hold out well."
The sale of the book was large and satisfactory. It was, of course, opposed, from its advanced views as to the age of the world, but Lyell wisely made no reply. He said, "I have sworn to myself that I will not go to the expense of giving time to combat in controversy. It is an interminable work." A great lesson, learned early.