The calculus of probabilities, when confined within just limits, concerns the mathematician, the experimenter, and the statesman. From the time when Pascal and Fermat established its first principles, it has rendered most important daily services. This it is which, after suggesting the best form for statistical tables of population and mortality, teaches us to deduce from those numbers, so often misinterpreted, the most precise and useful conclusions. This it is which alone regulates with equity insurance premiums, pension funds, annuities, discounts, etc. This it is that has gradually suppressed lotteries, and other shameful snares cunningly laid for avarice and ignorance. Laplace has treated these questions with his accustomed superiority: the 'Analytical Theory of Probabilities' is worthy of the author of the 'Mécanique Céleste.' A philosopher whose name is associated with immortal discoveries said to his too conservative audience, "Bear in mind, gentlemen, that in questions of science the authority of a thousand is not worth the humble reasoning of a single individual." Two centuries have passed over these words of Galileo without lessening their value or impugning their truth. For this reason, it has been thought better rather to glance briefly at the work of Laplace than to repeat the eulogies of his admirers. JOHN ARBUTHNOT (1667-1735) Arbuthnot's place in literature depends as much on his association with the wits of his day as on his own satirical and humorous productions. Many of these have been published in the collections of Swift, Gay, Pope, and others, and cannot be identified. The task of verifying them is rendered more difficult by the fact that his son repudiated a collection claiming to be his 'Miscellaneous Works,' published in 1750. [Illustration: JOHN ARBUTHNOT] John Arbuthnot was born in the manse near Arbuthnot Castle, Kincardineshire, Scotland, April 29th, 1667. He was the son of a Scotch Episcopal clergyman, who was soon to be dispossessed of his parish by the Presbyterians in the Revolution of 1688. His children, who shared his Jacobite sentiments, were forced to leave Scotland; and John, after finishing his university course at Aberdeen, and taking his medical degree at St. Andrews, went to London and taught mathematics. He soon attracted attention by a keen and satirical 'Examination of Dr. Woodward's Account of the Deluge,' published in 1697. By a fortunate chance he was called to attend the Prince Consort (Prince George of Denmark), and in 1705 was made Physician Extraordinary to Queen Anne. If we may believe Swift, the agreeable Scotchman at once became her favorite attendant. His position at court was strengthened by his friendships with the great Tory statesmen.