234 «HEEP HUSBANDRY IN THE SOUTH. 



LETTER XV. 



ANATOMY OF TAii iHEEP (Continued)— DISEASES AND THElll TREATMKlVT. 



llie Thoracic Viscera.. .Thj Diaphragm... The Thorax... The Heart, Arteries, Cn|nllaries, and Vein*... 

 Tne Lungs... The Windpips. Larynx and Phurynx... The Thyroid and Parotid Glands. . .The Head »ni 

 ito structures... The Krain ..The Nerves... The Teeth. ..The Lower Extremities. ..Tlie Hitlex CanKl. .. 

 Febrile diseases — those of Europe which aie not common here. ..Ophllinlniia— popular remedies — proper 

 treatment. ..Pneumonia — tymptoms — Mr. 8poo(ier's prescription for. .. Bronchitis -(•ympioms — tre-»imenl 

 ...Catarrh— ordinarily not daniierous— preventives. ..Mah^nant Epizootic Catarrh— pie valence in the 

 N-irthei-n States — character of the disease has not been understood — prevalence in author's tiock— how 

 produced -symptoms — post-mortem appe-irances — character of the disease ascertained— Nosology^ 

 treatment, &'c. ..The Rot— its diagno-is— post-mortem appearances— description of the Fluke— causes of 

 the Hot— treatment. ..Diarrhea— cause— diagnosis— treatment. . . Dysentery— cause— dirterence between 

 It and diarrhea— treatment... Garget— seat ai>d origin of the disease— treatment. ..Nervous Diseases... 

 Apoplexy— unrecognized cases of it— several cases detailed— symptoms— treatment. ..Phrenitis- ..Tet- 

 anus. .Epilepsy... Rabies... Neither of them common in this country.. .Paralysis— symptoms — treat- 

 ment. .Colic — symptoms — attributed to intussusception— true cause— treatment. 



THE THORACIC VISCERA. 



Among these, for convenience, I will include the diaphragm. 



The Diaphragm. — The diaphragm or midriff is a muscle extending en- 

 tirely across the inner cavity of the body, separating the abdomen from 

 the thorax or chest. Its structure is unique, and beautifully adapted to the 

 functions it has to perform. Its outer margin is muscular, giving it the ne- 

 cessary power of contraction, while toward the middle it changes into a 

 transparent tendonous substance. Through this tendonous substance pasa 

 tlie (Esophagus, the aorta, and the vena cava. 



If the parts of the diaphragm which immediately surround these vessels 

 had been muscular, every contraction of the former in the act of respira- 

 tion, would have compressed the latter, and therefore interfered with the 

 passage of the food to the stomach, and the circulation of the blood. In a 

 slate of rest the diaphragm is convex toward the thorax. When contract- 

 ed and flattened, therefore, it enlarges the cavity of the thorax, and air 

 rushes into the lungs. Its alternate contractions and relaxations mainly 

 produce the act of respiration or breathing. 



The Thorax. — Without injuring th*^ diaphragm, divide the sternum and 

 brisket of the sheep longitudinally through the center, with a fine saw, and 

 on pulling the lower extremity of the ribs slightly apart, the thorax will be 

 disclosed in its natural arrangement. It consists of three cavities, formed by 

 the doublings of the pleura, a thin serous membrane, which lines the whole 

 interior of the chest. Two outer and larger cavities (the right one being 

 the largest), contain the lungs — a third and smaller one, lyinfr between the 

 posterior portions of the former, contains the heart. The cesophagus pass- 

 es through the upper portion of the thorax, over the lungs and heart, and 

 between them and the spine, to the lower portion of the neck. 



The Heart, Arteries, Capillaries, and Veins. — With the size and 

 general appearance of the heart, all are familiar. Enclosed in a mem 

 braneous sac — the fericardium — it hangs suspended by its superior attach- 

 ments to the roof of the thorax, its lower extremity nearly reaching to il3 

 floor, and pointing toward the left side. The heart has two cavities on 

 each side, termed auricles ?i\\A ventricles The chvle and venous blood are 



