of Edinburgh, Session 87 
themselves. The author therefore believed that it would be much 
more to the interest of science to pursue his researches inde- 
pendently of all previous inquiry, divesting himself of all foregone 
conclusions, and making the facts which he has collected speak for 
themselves. By following this plan he derives two advantages : 
firstly, that of avoiding a tedious recapitulation of the facts and 
deductions to be found in other works ; and, secondly, that of 
drawing an unbiassed opinion upon the subject, which may the 
more confidently, on that account, be employed in comparison with 
results obtained in other localities. 
The difiiculties attending inquiries into the infiuence of weather 
upon mortality are manifold and intricate. All other causes, to 
which might, altogether or in part, be due the facts observed, must 
be abstracted and carefully weighed before the true balance of 
meteorological influence can be justly ascertained ; and when this 
is done, there still remains a deduction to be made for error arising 
from the unequal distribution of meteorological phenomena even 
over an area so limited as that of a single city. Whether de- 
pendence can be placed upon the accuracy of the returns of the 
causes of death made to the Kegistrar- General is another question 
of serious importance in such investigations. These and many 
other obstacles arise to bar logical exactness ; but where the aim is 
simply to obtain an approximate knowledge of the subject, the 
author believes his data are abundantly accurate. 
The meteorological data are taken from the collected returns 
from all the stations of the Meteorological Society of Scotland, as 
reduced by the Astronomer-royal. The stations have a mean lati- 
tude of 56° 30' N., mean longitude of 3° T W., and a mean ele- 
vation of 222 feet nearly. 
The mortality tables are constructed from the returns made by 
the Eegistrar- General for Scotland respecting the eight larger 
towns. The period over which the investigations extend is six 
years — namely, from 1857 to 1862 inclusive. The meteorological 
data did not admit of extension over a longer period. The author 
regrets that he is unable to include ozone and electricity in his in- 
vestigations. With respect to electricity, he has no data applicable 
to the places and period under examination ; and with reference to 
ozone, he submits, that until the chemistry of that subtile agency 
