72 DISEASES OF THE TRACHEA AND BRONCHI. 



press it, the pressure of expiration is greater than the inspiratory pres- 

 sure. But, if we keep in view the action of forced expiration, and the 

 condition of the J'ing in intense and extensive bronchitis, the matter 

 assumes a different aspect In forced expiration we press the dia- 

 phragm upward by energetic contraction of the abdominal muscles, and 

 thus exert a considerable pressure upon the lungs. This pressure acts 

 as well upon the air-vesicles as upon the contracted bronchial tubes. 

 The former cannot be cleared by the pressure, as this very pressure 

 closes their outlets. Even when removed from the body, we are unable 

 to diminish the volume of such a lung by squeezing it. I have been led 

 to this simple explanation, by frequent observation that, in this class of 

 patients every expiration is forcibly effected by meai\s of the muscles of 

 the abdomen, the sibilant rhonchus alone being audible at the time. 

 If we lay the ear upon the thorax, we hear notliing but that disseminated 

 sibilant rhonchus. Air enters in too small quantity, and, above all, too 

 tJowly to give rise to the whispering friction-sound which we call 

 vesicular murmur. Where it exists it is overborne by the whistling 

 sounds. Afterward we hear the wide-spread fine rattle, of minute bub- 

 bles (subcrepitant rales). 



C. ^Bronchial Catarrh of the New-born. New-born children very 

 often contract catarrh of the respiratory passages, principally from inef- 

 ficient protection against chilling during washing and bathing, etc. 

 The symptoms of it have hardly any resemblance to those of the 

 disease described above, although the malady is exactly the same. 

 The complaint is almost always mistaken by unphysiological phy- 

 sicians, and regarded as an " organic affection of the heart, in conse- 

 quence of which the child is fortunate in dying so soon." In such 

 cases children have sneezed a few times, have perhaps coughed a little, 

 otherwise appear well, and often inclined to sleep. The parents rejoice 

 over their quiet, contented babe; they do not notice that it only 

 breathes superficially. The physician is not called in, or, if he comes, 

 he finds no occasion to take account of the breathing; but a great 

 change comes over the child, usually with suddenness. The face be- 

 comes pale, or, together with the whole body, changes to an ashy hue ; 

 the nose grows peaked, the eyes dull, the arms and legs hang down 

 inertly. The temperature of the surface is lowered, and unequal ; an 

 acute cyanosis is diagnosticated, an unhappy conception, wherein ex- 

 treme vascular engorgement is confounded with the condition which 

 imparts the bluish hue to the lips of the dying, and which is really 

 owing to the beginning of that contraction of the arteries and discharge 

 of their contents into the capillaries and veins which we always find 

 post mortem. 



The explanation of the&e symptoms is easy. As long as 



