of population in Europe and America, 149 
I am aware that the evidence of — - received by many 
minds with a certain measure of doubt; shall endeavor so 
to add proof to proof, and to draw these frome such authoritative 
sources, that no doubt can fairly remain ase my remarks 
— the following self-evident laws. 
lst. That, while a result or event in individual instances is ever 
tense and uncertain, this result or event when calculated from 
or upon masses of instances becomes proportionately certain and 
invariable. 
2d. That, to apply this principle to the case we are now con- 
sidering, the absolute number of living births in a given popula- 
respect ae advanci - 
3. Tha en _ olute number of still births at the full period of 
Pie nema ing from natural causes in a given time ina 
given population should be always nearly the same; increasing 
only in proportion to the actual 1 increase of the population, and 
decreasing with the progress of medical science. 
4th. That the absolute i 8 of premature births, occurring 
from natural causes in a given time in a given population 
should be always nearly the same; increasing only in Mie 
to the actual increase of the population, and decreasing with t 
progress of medical science. 
5th. That the relative number of still births from natural causes, 
at the full period of pregnancy and premature, as compared with 
the hving births in a given population in a given time should be 
Ways nearly the same; not being affected by an increase of 
eae and constantly lpetieed by the progress of medical 
ie. That the relative number of still births from natural causes, 
at the full period of pregnancy and premature, as compared with 
& general mortality in a given a et in a given time, 
should remain pixies early the same, not being affected by an 
increase of population me but slightly by the progress of medi- 
cal science 
7th. That the relative number of still births from natural causes 
Premature and at the full period of preevancy, should remain 
aways fergie’ the same compared with each other; neither bs 
em 
It has a y become aueiae that the 2d of these ese proposi- 
tions aise ie reo: with existing facts ; that the absolube num- 
ber of Livi births in Europe and in this country does not re- 
