t “3 1 
born live to be married. Agreeably to this, it ap- 
pears alfo from the account I have referred to, that 
' explanation of a child juft born in Madeira is 
about 39 years, or near double the expectation of a 
child juft born in London. For the number of inha- 
bitants was found, by a furvey made in the beginning 
of the year 1767, to be 64,614. The annual me- 
dium of burials had been, for eight years, 1293 5 
births 2201. The number of inhabitants, divided 
by the annual medium of burials, gives 49.89, or the 
expeSiation nearly of a child juft born, fuppofing the 
births had been 1293, and conftantly equal to the 
burials, the number of inhabitants remaining the 
fame. And the fame number, divided by the annual 
I have {hewn how the allowance is to be made for 2d and 3d 
marriages 5 but it is not fo confiderable as to be of any particular 
confequence 5 and, befidesj it isj in part, compenfated by the na- 
tural children which are included in the births, and which raife 
the proportion of the births to the weddings higher than it ought 
to be, and therefore bring it nearer to the true proportion of the 
number born annually, to thofe who marry annually, after de- 
ducing thofe who marry a 2d or 3d time. 
In drawing conclufions from the proportion of births 
and burials in different fituations, fome writers on the increalc 
of mankind have not given due attention to the difference in 
thefe proportions arifing from the different circum fiances of in- 
creafe or decreafe among a people. One inflance of this I have 
now mentioned ; and one further inflance of it is neceflary t» 
be mentioned. Tire proportion of annual births to weddings 
has been confidercd as giving the true number of children derived 
from each marriage, taking all marriages one with another. 
But this is true only when, for many yearSj the births and bu- 
rials have kept nearly equal. Where there is an excefs of the 
births occafioning an increafe, the proportion of annual h\n\\s to 
weddings mufl be lefs than the proportion of children derived 
from each marriage ; and the contrary mufl take place where 
there is a decreafe, 
VoL. LIX. 
a 
medium 
