Mensuration. 199 



cessively to the lower end of the eighth rib on the two sides, and the 

 difference marked, and lastly, from the lower end of the third rib 

 to the lower end of the eighth, These measurements should be 

 made at one stage of the respiratory act, say when the chest is 

 fully dilated, and similar measurements when the chest is collapsed, 

 to ascertain any difference in the expansion of the two sides of 

 the chest. In the smaller animals, any difference in the expansion 

 of the two sides may be observed by inspection only, the practi- 

 tioner standing directly behind the animal and watching the 

 movements of the two sides from this standpoint. 



A permanent dilatation of one side may be seen in cases of 

 water in the chest confined to one side, and particularly if of some 

 standing. Complete hepatisation of one lung gives a similar result. 

 The intercostal spaces are observed to be wider than usual in such 

 cases, and the movements of the opposite side of the chest are 

 much more extensive than of the affected one. 



A collapse with limited movement of one side is an accompani- 

 ment of chronic disease of the lung, with wasting of its substance 

 as in cases of tubercular deposit. 



