পাতা:পদার্থবিদ্যাসার.djvu/৮৫

74 ditional strength to the fingers, by enabling them to keep firmer hoid of any thing. And farther, you may also consider. that works of art, such as writing, drawing, painting, and instrumental music, are performed by these live small members of the human body. And to crown and persecs the human fabrie, the whole body is covered with it fine skii), as a curiously wrought upper garment without a seam ; through which are an infinite number of invisible spiraeles, or apertures, which we call pores. Pup, Of whai particular use are these pores ? Tut. Through these, the superfluous moisture of the body evaporates, which we usually term perspiration ; the regularity of whici is so uecessary for the health of the body, that when perspiration is stopped, it is rows the body into a fever, which is of: ten fatal. LXercise and cleanliness aie the best promoters of this necessary perspiration. Bup. !!• • w is it known thai perspiratioi, is continually going on in the Hunan body ? T'u'. This is evident from a variety of phenomena: the fact is easily ascertained by experiment. Pup. l should for: glad to try it for myse{i. Tut. Hold a piece of polished metal that is quite clean and dry, close to any part of the bare body, in warm weather, and it will quickly determine the fact. If you put your naked arın into a wide-mouthed chemical glass vessel, that is very dry, you will soon see the internal surface of the glass dimmed with the exhalation from the arm ; and if it be kept there some time, streaks of moisture will be seen trickling down. its sides.