fully into the history of the test, than we deem necessary, believing as we do, that it can never afford evidence sufficiently decisive for practical application. Daniel has proposed a modification of Plouquet's test, but which is more objectionable even than that which he professes to improve. The same physiologist considers that an inference may be drawn from the increased circumference of the thorax, and the vaulted appearance it assumes after respiration. The objections urged by Dr. Hutchinson to these latter indications appear to us to be unanswerable; the circumference of the thorax, says he, varies so much in infants of the same age and sex, both absolutely and in proportion to other parts of their body, that it cannot be possible to obtain any decisive evidence from it. The vaulted appearance of the chest is almost equally fallacious in the generality of cases, or else it is devoid of utility; because the figure of the thoracic parietes is not much changed until respiration has been fully established, and then we have other and more certain means of detecting its existence. Besides which, it appears from the experiments of Schmitt, that the thoracic parietes were distended outwards by artificial insufflation after death, as much as they are by actual respiration as it occurs in the new-born infant. With these remarks we shall dismiss the subject of Docimasia Pulmonaris, and proceed to inquire whether the structure of the heart is capable of affording any useful indications. There can be no doubt but that, some time after birth, we shall find on inspecting the heart, evident marks of the altered course of the circulation. The foramen ovale will be closed, and in extending our examination, we shall find that the ductus arteriosus and canalis venosus, have collapsed and assumed the appearance of imperforated
