204; Notices respecting New Books. 



siderably less than what I had obtained with the bar of 

 wrought iron, I repeated the experiment with the latter in the 

 same register that I had employed for the former, and ob- 

 tained the measures of 0° 35' and 2° ^-t' — nearly agreeing 

 with the previous determination : so that there can be no doubt 

 that cast iron expands less than wrought iron, though the 

 rate of increase for the higher temperature appears to be the 

 same in both. 



[To be continued.] 



XLIV. Notices respecting New Books. 



Life Tables founded upon the Discovery of a Numerical Lato regu- 

 lating the Existence of every Human Being, S^c. By T. R. Ed- 

 monds, B.A., late of Trinity College, Cambridge. 



IN this work, of which we have been favoured with a copy, the 

 author announces the discovery of a new law of mortality, which 

 he has applied to the construction of a considerable number of an- 

 nuity and other tables. The announcement in the title-page, that 

 the tables are founded upon the discovery, instead of the law, is one 

 of those inaccuracies of expression which occurin other parts of the 

 book, and which bespeak carelessness at least on the part of the 

 author, in the construction of his sentences. 



The new law is thus announced. — During the succession of years 

 and moments of life, the continuous change in the force of mortality 

 is subject to a very simple law, being that of geometric proportion. 

 But instead of one uniform progression, there are three distinct or- 

 ders, corresponding respectively to infancy, manhood, and old age. 

 The common ratios of the three geometric series are, we are to\d,Jixed 

 and immutable for all human life in all ages of the world. They are 

 also said to be now first discovered : but it is not stated by what pro- 

 cess, nor is it at all important to inquire; for they appear to be wholly 

 empirical, and the tables founded upon them are of no practical 

 value whatever. 



Indeed this is the opinion of the author himself. For in page xii. he 

 says, with great truth, that "in allclasses of a population the mortality 

 is continually varying." Hence the new fixed and immutable law 

 cannot be applicable, except at some particular moment, to any of 

 such classes. The author afterwards very justly remarks, that " to 

 generalize from a single fact is absurd ; and it is an absurdity of this 

 kind into which those people fall who would apply observations made 

 on one kind of life to all kinds of life." A remark which implies an 

 equal absurdity in applying his own general law, which isjixedfoor 

 all human life, to any one class or condition of mankind, — or in 

 other words, to any one practical purpose. 



But although we concur with the author in the uselessness of his 

 own tables, we dissent from most of his opinions relative to the com- 

 parative value of others. 



