into the gardens of Florence, when the gardeners were working the pumps: it was that which inspired those gardeners, when, not being able to raise the water above the height of 32 feet, to ask him the cause, and by that question piqued the vanity of the philosopher, put in action by so casual a question, that obliged him to make this natural effect the subject of his thoughts, till, at last, by discovering the weight of the air, he found the solution of the problem. In the moment when the peaceful soul of Newton was employed by no business, and agitated by no passion, it was also chance that, drawing him under an apple tree, loosened some of the fruit from the branches, and gave that philosopher the first idea of his system on gravitation: it was really this incident that afterwards made him turn his thoughts to inquire whether the moon does not gravitate towards the earth with the same force as that with which bodies fall on its surface? It is then to chance that great geniuses are frequently obliged for their most happy thoughts. How many great minds are confounded among the people of moderate capacities for want of a certain tranquillity of soul, the question of a gardener, or the fall of an apple!" Of the "exclusive qualities of the Mind and Soul," Helvetius observes:-- "My view in the preceding chapters was to affix clear ideas to the several qualities of the mind, I propose in this to examine if there are talents that must necessarily exclude each other? This question, it is said, is determined by facts; no person is, at the same time, superior to all others in many different kinds of knowledge. Newton is not reckoned among the poets, nor Milton among the geometricians: the verses of Leibnitz are bad. There is not a man who, in a single art, as poetry, or painting, has succeeded in all the branches of it. Corneille and Racine have done nothing in comedy comparable to Molière: Michael Angelo has not drawn the pictures of Albani, nor Albani painted those of Julius Romano. The genius of the greatest men appears then to be confined within very narrow limits. This is, doubtless, true: but I ask, what is the cause? Is it time, or is it wit, which men want to render themselves illustrious in the different arts and sciences? The progress of the human mind, it is said, ought to be the same in all the arts and sciences: the operations of the mind are reduced to the knowledge of the resemblances and differences that subsist between various objects. It is then by observation that we obtain, in all the different kinds of study, the new and general ideas on which our superiority depends. Every great physician, every great chemist, may then become a great geometrician, a great astronomer, a great politician, and the first, in short, in all the sciences This fact being stated, it will doubtless be concluded, that it is the short duration of human life that forces superior minds to limit themselves to one kind of study. It must, however, be