The absence of the respiratory sound may arise from an impermeable state of the cells, or the bronchial ramifications, and have for its cause the presence of tubercles, or other matter of obstruction; or it may proceed from some secretion or effusion, the produce of disease. But the student, when he does not discover any sound of respiration, must be careful to avoid drawing false conclusions from his yet imperfect tact in the art; it so commonly happens, that calm respiration does not afford any distinct perceptions to the unpractised ear. It appears to me worthy of consideration, whether or not, in some states of hydrothorax, the evacuation of the fluid by puncture may be a desirable expedient? The increased accuracy of diagnosis attainable by means of the stethoscope, would here be very important towards deciding the fit period for the performance of the operation. In the narration of my cases, I have not made mention of percussion. Suffice it to observe, that I have seldom used it except in chronic diseases of the chest, as the indications by the stethoscope, in addition to the general symptoms, have afforded me all the information which I have required. I shall here bring my Observations to a conclusion, having endeavoured to present in a concise and intelligible form, a part of the results of my own experience in the use of the stethoscope; and to consider briefly the merit of some points of practice; inquiring at the same time into the nature of several medicines, which claim our particular attention, both from their novelty and their importance. The value of any practical opinion must be decided by the suffrages of the many; but, whoever collects and records his facts with care and fidelity, renders some contribution to the advancement of the medical art. FINIS. MALLETT, PRINTER, WARDOUR STREET. FOOTNOTES: [1] I am inclined to think, that during the inflammatory diathesis, a larger proportion of fibrin than natural is actually formed in the assimilating process; and it is further probable that it is not distributed as usual to the several fibrous textures of the body. In my Essay on the Blood, I have suggested this last hypothesis. [2] See Forbes’s Translation, p. 19. [3] In 1822, M. J. A. Legumeau de Kergarader published a Memoir “Sur l’Auscultation,” &c. in reference to gestation; and in 1824, M. J. Lisfranc, a Memoir, to show the powers of the stethoscope in enabling the surgeon to detect with greater nicety the fractures of bones. I have read these essays, which must be allowed the praise of ingenuity; and I conceive that cases may occur of each description, in which the aid of the stethoscope would be found not unimportant.