On one of these exploring tours we entered a limestone quarry--long before geology was so popular as it is now. It is impossible to describe the delight and wonder with which I began to collect the shells found in the carboniferous limestone which crops out in High Blantyre and Cambuslang. A quarry-man, seeing a little boy so engaged, looked with that pitying eye which the benevolent assume when viewing the insane. Addressing him with, "How ever did these shells come into these rocks?" "When God made the rocks, he made the shells in them," was the damping reply. What a deal of trouble geologists might have saved themselves by adopting the Turk-like philosophy of this Scotchman! My reading while at work was carried on by placing the book on a portion of the spinning-jenny, so that I could catch sentence after sentence as I passed at my work; I thus kept up a pretty constant study undisturbed by the roar of the machinery. To this part of my education I owe my present power of completely abstracting the mind from surrounding noises, so as to read and write with perfect comfort amid the play of children or near the dancing and songs of savages. The toil of cotton-spinning, to which I was promoted in my nineteenth year, was excessively severe on a slim, loose-jointed lad, but it was well paid for; and it enabled me to support myself while attending medical and Greek classes in Glasgow in winter, as also the divinity lectures of Dr. Wardlaw, by working with my hands in summer. I never received a farthing of aid from any one, and should have accomplished my project of going to China as a medical missionary, in the course of time, by my own efforts, had not some friends advised my joining the London Missionary Society on account of its perfectly unsectarian character. It "sends neither Episcopacy, nor Presbyterianism, nor Independency, but the Gospel of Christ to the heathen." This exactly agreed with my ideas of what a missionary society ought to do; but it was not without a pang that I offered myself, for it was not quite agreeable to one accustomed to work his own way to become in a measure dependent on others; and I would not have been much put about though my offer had been rejected. Looking back now on that life of toil, I can not but feel thankful that it formed such a material part of my early education; and, were it possible, I should like to begin life over again in the same lowly style, and to pass through the same hardy training.