50 MICROSCOPIC OBJECTS. 



a subject of deep interest to the reflective mind. What 

 subject can be more interesting than the study of the 

 means by which the pianist executes a rapid piece of 

 music ? or the precision with which the anatomist dissects 

 the most dehcate tissue, and the artist pourtrays every 

 expression of the human face ? The action of a muscle 

 is well understood ; the motions it produces being 

 occasioned by its contraction, and the muscle swelliug at 

 the same time that it shortens ; but in what manner the 

 individual fibres act, remained for the Microscopist to 

 ascertain. The theory at present in fashion is, that the 

 ultimate form of aU organic bodies is a cellule. This 

 form, however, in the present case involves some diffi- 

 culties. In 1840 Mr. Pritchard was led to consider this 

 subject ; and it occurred to him that the best method of 

 discovering the true form of the ultimate fibre of muscle, 

 would be to select a fibre from the most highly developed 

 muscle. This he accordingly did, and prepared several 

 slides of fibre.'' From a careful microscopic examination of 

 these, he was satisfied that the fibre was spiral and inclosed 

 in a membranous sheath. Some time afterwards one of 

 these preparations fell into the hands of Dr. Leeson of St. 

 Thomas's Hospital, who also felt persuaded of their spiral 

 nature; but after making himself preparations from 

 several muscles, which would not support this view, he 

 considered some error might have arisen in the naming 

 of the slide he had from Mr. Pritchard. Dr. Leeson 

 determined to follow up the investigation, appUed to Mr. 

 P. for the name of the muscle, and was informed accord- 



