Eurvhorjhlps. 2 7 7 
mations now in ufe, I have invariably found the latter to be 
erroneous; nay, in fome cafes, the values were aim oft twice 
as great as they ought to have been, 1 his is particularly true 
when one of the lives is very young, and both or either o e 
other lives are very old. In reverfions of this kind I believe 
that this is generally the cafe, and that it feldom happens that 
the ages of the three lives are nearly equal. The approxima- 
tions therefore can hardly ever be ufed with fafety, and it will 
certainly be mod prudent not to have recourfe to them when 
the corred values can be obtained. Should the difficulties 
attending the folution of the remaining problems which in- 
volve three lives be furmounted (and the talk may not perhaps 
be impoffible), the hypothefis of an equal decrement of life, as 
far as it relates to any ufeful purpofe in the doftrine of annui- 
ties, may then be totally abandoned. Or lhould it even e 
found ineradicable to deduce folutions of thofe problems 
which are fiddly and accurately true ; yet, I am fatisfied from 
m y own experience that fuch near approximations may be pro- 
cured as to render this hypothefis equally unneceffary. 
