THE 
/? 
VETERINARIAN. 
JANUARY, 1833. No. ei. 
MR. YOUATT’S VETERINARY LECTURES, 
DELIVERED AT THE UNIVERSITY OF LONDON. 
LECTURE XXIV. 
The Structure of the Lungs—The Pulmonary Capillary Circa- 
latiori — The Change effected in the Blood—Catarrh in the Horse, 
Ox, and Dog—Chronic Cough, 
OF the intimate structure of the lungs I have little to say to 
you, and that little far from satisfactory. They are the seat of 
the pulmonary circulation. They convey through their com- 
^ paratively little bulk the blood, and all the fluids beside scarcely 
become blood, or soon separated from it, which traverse the whole 
of the frame. Then it is evident that they must contain innumer¬ 
able bloodvessels, or, rather, that they must, in addition to the 
ramifications of the air-tubes, consist of a mass or congeries of 
bloodvessels, or the balance or equilibrium of the circulation could 
not be preserved. They do so: the only account which I can 
give you of the structure of the lungs is, that they consist of 
countless ramifications of air-tubes and bloodvessels connected 
together by intervening cellular substance. 
In order to examine them, however, as minutely as I can, I 
take the lungs of an ox ; an animal in w^hich they are considerably 
developed, and in which, from his quiet, regular way of living, 
they are generally not much disorganized. If you compare these 
specimens, taken from the horse, the dog, and the ox, you wdll 
immediately perceive how much more perfectly their structure is 
exhibited in the last, and for the reason that I have stated. 
The Divisions of the Lungs. —The lungs form two distinct 
bodies, the right somewhat larger than the left; and they are di¬ 
vided from each other by that duplicature of the pleurae w’hich 
has been already described—the mediastinum. Each lung has 
the same structure, properties, and uses. Each of them is sub¬ 
divided ; the right lung consists of five lobes, the left of two. These 
divisions are different in our different patients, but for what 
physiological reason I am unable to tell. In the horse the right 
VOL. VI. A 
2 _\ 0 , 
