vanced in decomposition before the lungs are found to participate in it. Camper instituted a number of experiments upon infants, at Amsterdam, by exposing their bodies to the action of water, as well as to that of air, and his results fully confirm the fact we have just stated. Ballard was called upon to examine a child, the muscles of whose face were reduced to "boulli"—were in a state of solution—and in which putrefaction had advanced so far as even to prevent discrimination of the sex, notwithstanding which the lungs immediately sunk. If we make incisions into these organs, when in a state of advanced putrefaction, we shall observe air bubbles of a considerable size, and running in lines along the fissures, between the component lobuli of the lungs; where such phenomena present themselves we may be assured, says Dr. Hunter, that the air is emphysematous, and not that which has been introduced by respiration; for, in this latter case, the air bubbles will be hardly visible to the naked eye. But there still remains another mode by which we may determine whether the gas diffused in the texture of the pulmonary organs be the effect of respiration, or decomposition. It consists in pressing portions of the lungs between the fingers, or twisting them in a folded cloth, with all the force we can command; when, should the gas have arisen from putrefaction, the portions thus treated will sink in water; a change which no force, however powerful, will effect in those cases where the gaseous distention has arisen from respiration.
From the view which we have taken of the hydrostatic test, and of the objections which have been urged against its validity, the practitioner will be enabled to appreciate its importance. Plouquet, de-
