GLASGOW COLLEGE INTRODUCTORY LECTURE. 833 
the lesson that his duties demand—that he shall not only be 
Avell versed in the treatment of serious disorders, and the 
performance of formidable operations, but that he should 
know well the common-sense science of every-day life. I • 
cannot too strongly impress upon you, gentlemen, the neces¬ 
sity of understanding the principles of ventilation, disinfec¬ 
tion, the chemical examination of drugs, of air, of water, and 
of urine. Much evil might be obviated by attention to the 
quality of the air and water with which we provide our 
patients. A few simple tests are in many cases sufficient to 
inform you of the purity of both the air and the water. But 
as these points will be fully discussed in my lectures, I will 
not at this time advert further to them. The present state 
of science affords a brilliant contrast to its gloomy condition 
in bygone years, when but a scanty number of its great 
facts were known and its principles understood. The science 
of to-day has unfolded to us things never dreamt of a century 
ago; and things which, had they been known then, would 
have been ridiculed into oblivion by the followers of scien¬ 
tific research. Many of the sciences are ardently pursued and 
considered as proper objects of study, not only on account of 
the intellectual pleasure they afford, not only because they 
enlarge our views of nature, and enable us to think more 
correctly with respect to the beings and objects surrounding 
us, hut because they lead us to facts and discoveries of the 
utmost practical value and importance. 
As no man can know science thoroughly, it is necessary to 
divide it into departments, and constitute several sciences, in 
order that he may grasp, in a satisfactory manner, all the 
facts and principles contained in them. Chemical science is 
of vast usefulness. This science attends the mineralogist and 
the geologist into the bosom of the earth and on the summits 
of the mountains, to develop the nature, the composition, the 
changes, and often the origin, as well as the future fall, of 
the different beds of the globe and fossils of which they are 
formed. To the botanist and agriculturist it opens a treasure 
of discoveries and prospects adapted to explain the secret of 
vegetation. To the physiologist it holds out the only pros¬ 
pect which he has of ever discovering the sources of animal 
life. To the meteorologist it has thrown a new light on all 
the great changes which take place in the atmosphere. 
Chemistry has now become the science most adapted to the 
sublime speculations of philosophy, and the most useful in all 
the operations of the arts. Exact in its processes, sure in its 
results, varied in its operations, abounding with resources 
from its instruments, its apparatus and its manipulations; 
