the same supposition may be computed, according to rules that are well known. M. Duvilard has found that the mean duration of human life is increased at least three years by the vaccine inoculation." p. 69. But as this review is now in danger of becoming longer than the book reviewed, we shall conclude, with recommending to our readers the perusal of the work itself; and with assuring them, that they will find in it much valuable and important matter, which has not fallen within the scope of this analysis. FINIS. REVIEW OF BARON DE ZACH, ATTRACTION DES MONTAGNES. * THE Baron de Zach is known in the scientific world as an astronomer, and as the author of several works on the practical parts of the mathematical sciences. He is a native of Germany; and his principal residence, if we mistake not, has been at the court of the Prince of Saxe-Gotha. He appears, from what is mentioned in these volumes, to have been employed in 1802 by the King of Prussia, in constructing a map of Thuringia, from an actual survey. Several years ago he visited England; and resided there for a considerable time. He lived much in the family of Lord Egremont ; and we owe to him the discovery of several unpublished MSS. of Harriot, one of the ablest and most inventive mathematicians of the age in which he lived. These the Baron found among the papers * Fromthe Edinburgh Review, Vol. XXVI. (1816.)-ED. |