RESPIRATION. 
307 
the town in which I reside), that in those stables, and on those 
farms where the influenza had previously run its course amongst 
horses, I have not as yet had a single case of the epizootic with 
the other stock. On the other hand, on those very identical farms 
that are now under the disease, and have had the cattle epizootic, 
not one single horse has been affected with it. 
RESPIRATION, 
ITS MECHANISM AND CHARACTERS ABSTRACTEDLY CONSIDERED. 
By Mr. R. Pritchard, V. .S'., Wolverhampton. 
[Continued from page 205.] 
The impediments to free respiration in a healthy horse are af- 
fairs of the greatest importance, to the trainer of the race horse 
more especially ; with the rider to hounds they are next in amount 
of consideration; and of considerable moment to every man that 
rides or drives fast. They consist of whatever obstructs or hinders 
the facile easy movement of the respiratory mechanism. First 
in magnitude is an accumulation of the adipose substance, and 
more particularly within the chest, beneath the serous tunic upon 
its internal walls, and about the base of the heart. Here this ma- 
terial seriously impedes respiration by diminishing the capacity 
or space of the pulmonary chambers and the expansion of the 
lungs. There is in the healthy condition of the heart ample room 
within the pericardium for all its motions ; and, as the first act of 
the organ is to contract, the chamber is always efficient in space 
for the returning dilatation of its walls ; therefore a deposit of fat 
about the base of the heart does not impede its movements by 
lessening the extent of the cavity of the sac, but by diminish- 
ing the rythm, more especially of the right auricle and ventricle. 
This being, as I before stated, the respiratory portion of the 
organ, an accumulation of fat interfering with the vibration of 
these cavities must impede the mechanism of respiration. A load 
of adipose substance, situated externally of the chest, is not 
only a burden upon the muscular fibres, but a dead weight upon 
the ribs to be moved by the inspiratory muscles. Whatever 
may be the apparent enlargement of the substance of the mus- 
cles in the fatted horse, not one fibre of the motor tissue is in- 
creased by such growth ; it is wholly of inactive material. The 
accumulation of fat within the cavity of the abdomen, between 
the peritoneum and the fascia of the muscles — beneath the sur- 
