In the diagnosis of the diseases of childhOod we are therefore very dependent upon the history of the case, and the amount of febrile disturbance; but it must be remembered that the quick circulation of childhood is much more readily excited than that of the adult, and the comparison must not be made between the pulse of infancy and that of age, in ooming to the conclusion that a child is suffering from inflammation of the lungs. That this is constantly done there can be no doubt, from the frequency with which mothers report that children have had such attacks, and that they have been told so by their medical attendant. In flammation of the chest, whether as pleurisy or pneumonia, is not by any means a frequent ailment of childhood—pleurisy is espe cially rare in the first years of life, and when pneumonia is pre sent its symptoms are invariably urgent. If anything be needed in the way of auscultation to confirm the diagnosis (and it is always wise to practise it), we find perhaps some difference in tone on percussion between the two sides of the chest, or it may be, absolute dulness • the breathing probably differs on the two sides, and we may be able to say that one is harsher than the other—more commonly, however, it is only less distinct on the affected side, and then, in place of crepitation, we find moist sounds; or, at all events, very coarse crepitation—never the fine sound heard in the adult. Along with this there may be very considerable bronchial irritation of the other lung, so that all the signs of disease may be suspected to be due to bronchitis, and in fact the cases are quite exceptional in which unaided ausculta tion could determine the nature of the affection.
Bronchitis occurs either as acute or chronic. In the former, the sonorous sounds are very rarely heard; there is adeal of fever, but it is not so severe as that of pneumonia, the not so pungent, and the signs of imperfect aeration of the blood are not present ; the breathing is louder or weaker, according to the amount of secretion present, and this often differs on the two sides. The principal indication derived from auscultation is the very general distribution of the morbid sounds; the absence of any difference in percussion would confirm the impression that the disease was simply bronchitis, but dulness on one side behind must not be taken as a proof that pneumonia is present; not only may an appearance of dulness be produced by more congestion, but the existence of tubercular glands at the root of one lung, which may have tended to excite the bronchitis, may also be the cause of absolute dulness.
Chronic bronchitis, which so often simulates, or is simulated by phthisis in the adult, is often quite undistinguishable from tuber cular disease in infancy. Here dissemination of tubercle is the rule ; its aggregation in masses, except in the bronchial glands, the exception. It is from the aspect of the child and the history of the case alone that we can judge, aided probably in some mea sure by the general symptoms, and occasionally by the character of the sputa. When we learn that the patient has had an attack of measles, or has suffered much during dentition—that the con stitution has not rallied, but cough has gradually supervened ; when there is a pallid, transparent skin, with long eyelashes and brilliant eyes, and the child is peevish and irritable, or languid and unexcitable, or remarkablf quick and intelligent—suspicions of tubercle are naturally excited ; and if, in addition to this we find emaciation, debility, heat of skin, followed by perspiration and diarrhoea, the probabilities are greatly increased. If, on the con Wiry, we learn that the first attack was feverish, or that after hooping.-cough, some years before, there has been great liability to ooughs and colds ; if the face be dusky, or the lips discolored, and, except from dread of an impending oough, the child's tem per be not materially altered ; if, m addition to this, we learn that the cough ends in copious expectoration, even though that should be tinged with blood—the diagnosis and the prognosis are con siderably more favorable ; haemoptysis in childhood is by no means a sign of phthisis. The stethoscope can scarcely afford any assistance in discriminating these affections; and it must be added that, when judicious treatment is employed in cases which have all the aspect of tubercle, the children so completely recover from the attack of bronchial irritation accompanying it, and are so often lost sight of subsequently, that no person of any experience will venture to give a decided opinion, except in very clearly marked examples of each disease. It is to be remembered that when the bronchial affection has passed, the signs of remaining consolidation at the apex are never found in childhood ; if any localization of tubercle prevail at this period of life, it is only in the glands at the root of the lungs.