DISEASES OF THE RESPIRATORY SYSTEM. 91 



has well set in, earlier a sibilus is present. In pneumonia 

 crepitus, dulness, and, later, various forms of rale and 

 sibilus are present, either generally diffused or circum- 

 scribed. In pleurisy there is first friction-sound, later an 

 absence of sound from the lower part of the chest accor- 

 ding to the amount of serous fluid effused. The loss of 

 sound alters with change in position of the patient, and 

 the superior limit of dulness is sharply defined and alters 

 from time to time in accordance with variations in the 

 amount of effusion. Such, roughly, are the indications 

 afforded by auscultation. It is unnecessary to enter fur- 

 ther into detail here, because the information as to the 

 exact extent of disease will depend entirely on the ex- 

 perience of the observer, and practically we find the dif- 

 ferent intrathoracic phenomena so intermingled that each 

 case is a problem in itself and must be solved from its 

 own indications. Cough is present in all cases, but that 

 of bronchitis is moist and wheezy, that of pleurisy parox- 

 ysmal, painful, and cut short, and that of pneumonia 

 occasional and small. In pleurisy there is pain on pres- 

 sure of the sides, also twitching of the muscles of the 

 walls of the chest. In both bronchitis and pneumonia 

 the temperature of the expired air is increased, but espe- 

 cially so in the latter. The pulse is . frequent, hard, and 

 small in pleurisy, oppressed and fast in pneumonia, fre- 

 quent but generally soft in bronchitis. In bronchitis and 

 pneumonitis there is frothy (rusty or whitish) expectoration, 

 but not in pleurisy. The dog with inflammation of the lungs 

 and pleura sits up with his fore legs apart (vide Pig. 1, 

 p. 9), often in the latter stages of the disease he stands 

 until he falls down to die. It has been remarked that in 

 pneumonitis the extremities become extremely cold, and the 

 nose, instead of dry and hot, is cold and very moist. In the 

 latter stages of chest disorder the patient becomes a pitiful 

 object, much emaciated, struggling for breath, obstinately 

 sitting or standing, tongue purple and hanging from the 

 mouth and rery foul, breath most offensive, teeth covered 

 with sordesj a haggard and distressful look. When 

 hydrothorax has set in the. animal lies down most unwil- 



