THE DISEASES OF CATTLE. 219 



The alteratives and tonics may be prepared as follows : — 



Powdered Iodide of Potassium, 1^ scruples. 



" Goldenseal, 1 drachm. 



Dissolve the potassium in a pint of water, then add the, gold- 

 enseal. This may be given daily for a week or more. 



THE PERICARDIUM AND ITS DISEASES. 



The pericardium is a membranous bag that surrounds the 

 heart ; it is known to butchers as the heart-bag, and is attached 

 to the sternum, diaphragm, and to the roots of the large blood- 

 vessels at the base of the heart. It is composed of two layers 

 united by cellular tissue ; the external one is composed of 

 fibrous tissue, the internal one is a smooth serous membrane, 

 similar to that which lines the cavity of the chest. This serous 

 membrane is studded by numerous vessels called exhalents, 

 from these issue a vapor of fluid, the purpose of which is to 

 guard against friction. The insertions of the pericardium are 

 such that it confines the heart in its proper situation, and aids 

 in sustaining a reciprocal action between the heart and lungs. 

 It is often the seat of a disease known as Pericarditis, 



PEfllCARDITIS. 



This disease consists of inflammation of the pericardium, the 

 causes of which are supposed to be nearly the same as those 

 of pleurisy or inflammation of other serous membranes ; viz., 

 sudden impressions of cold on the external surface, violence, 

 etc. A special cause has also been assigned for this disease ; 

 viz., the penetration of the pericardium by foreign bodies, such 

 as nails, needles, wire, etc., coming from the interior of the 

 stomach, working their way through it into the former. 



Symptoms of pericarditis. — There is considerable increase 

 in the force of the heart's pulsation ; the jugular veins are en- 

 gorged — larger than usual — and an undulating movement is 

 observed in them. There will be acute inflammatory fever, 

 generally preceded by rigors, shivering, and coldness, the vis- 

 ible surfaces of the nostrils and eyes are highly reddened in the 

 early stages, and rumination has ceased with loss of appetite ; 



