1868. | Its Recent Progress and Present Condition. 4] 
does for the sight. We know not who first applied his ear to the 
walls of the chest, to endeavour to learn, from the sounds thence 
emitted, the variations in the action and conditions of the organs 
therein contained; but he who first thought of interposing 
between the ear and the naked body a tube of some unyielding 
material, and thus made mediate auscultation an universally appli- 
cable mode of research, deserved to be ranked among the greatest 
benefactors to mankind. And an equal rank should be given to 
the inventor of percussion as a mode of examination, the man who 
first showed that by close attention to the varied quality of the sounds 
produced by a smart blow on the walls of the chest, most precious 
knowledge might be obtained of the condition of the contained viscera. 
The sense of touch also has not been without its cultivators. 
The tactus eruditus has long been one of the most highly valued 
accomplishments of the surgeon, but improved methods of palpa- 
tion have made it almost equally useful to the physician; and 
most valuable additions have recently been made to the information 
which the touch gives as to the pulse. The knowledge gained by 
gentle pressure with the tips of the fingers on a superficial artery, 
of the frequency, force, and other qualities of the action of the organs 
of the circulation, is necessarily uncertain, because it is subjective 
knowledge, and because therefore the accuracy of the observations 
must depend on the carefulness and experience of the observer, and 
the delicacy of his sense of touch. A beautifully imagined instru- 
ment now registers for us the pulsations, and describes on paper 
the height, form, and other qualities of each arterial wave. We 
must also regard as helps to the sense of touch the improved 
modes of applying the thermometer to the surface and the cavities 
of the body. Most precious knowledge is thus acquired as to the 
progress of febrile and inflammatory diseases, and our powers both 
of prognosis and of diagnosis have been immensely increased. 
To all these modes of rendering medicine more and more one of 
the exact sciences, must be added the improved modes of research 
furnished by chemistry. Our knowledge of the composition of 
organic bodies, and of the chemical changes constituting assimilation 
and degeneration, and of the processes of growth, secretion, and 
excretion, has only within the last quarter of a century acquired 
anything like the character of certainty. The physiological 
chemist has not only entered so far into the arcana of Nature as to 
be able to ascertain, to a great extent, how she does her work, but 
has even succeeded in imitating her operations. Not content with 
analysis, he has with considerable success attempted synthesis also. 
“ Already he has been able to produce a large number of organic 
compounds from carbonic acid, water, and ammonia, and even from 
the pure elements themselves. In fact, of the three great classes of 
alimentary substances, the production of the oleaginous is quite 
