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Show IG8 EXPRESSION OF SUFFERING: CnAP. VI. ren1oval of the young one. 1-Ien~e I was extretn~ly anxious to ascertain, as an extension of the relation between the contraction of the orbicular muscles and the shedding of tears in man, whether elephants when screaming or trumpeting loudly contract these muscles. At Mr. Bartlett's desire the keeper ordered the old and the young elephant to trumpet; and we 1:epeatedly saw in both animals that, just as the trumpeting began, the orbicular muscles, especially the lower ones, were distinctly contracted. On a subsequent occasion the keeper made the old elephant trun1pet much more loudly, and invariably both the upper and lower ·orbicular muscles were strongly contracted, and now in an equal degree. It is a singular fact that the African elepha~t, whic~, however, is so different from the Indian spemes that It iA placed by some naturalists in a distinct sub-genu~, when 1nade on two occasions to trumpet loudly, exluhibited no trace of the contraction of the orbicular muscles. From the several foregoing cases with respect to 1\fan, there can, I think, be no doubt that the contraction of the muscles round the eyes, during violent expiration or when the expanded chest is forcibly compressed, is, in some manner, intimately connected with the secretion of tears. This holds good under widely different emotions, and independently of any emotion. It is not, of course, meant that tears cannot be secreted without the contraction of these muscles; for it is noto~ rious that they are often freely shed with the eyelids not closed, and with the brows unwrinkled. 'rhe con~ traction must be both involuntary and prolonged, as during a choking fit, or energetic, as during a sneeze. The mere involuntary winking of the eyelids, though often repeated, does not bring tears into the eyes. Nor does the voluntary and prolonged contraction of CnAP. VI. WEEPING. 169 the several surrounding muscles suffice. As the lacrymal glands of childr n are easily .. rcit d, I p rsuaded my own and several other childr n of dif~ r nt ages to contract these muscles repeatedly with th C)ir utmost force, and to continue doing so as long as th y possibly could; but this produced hardly any effect. There was sometimes a little moisture in the eyes but not more than apparently could be acconnted fo;. by the squeezing out of the already secreted tears within the glands. The nature of the relation between the involuntary and energetic c.ontraction of the muscles round the eyes, an.d the secretion of tears, cannot be positively asc rta~ ned, but a probable view may be suggested. Tho primary function of the secretion of tears too·eth r . h ' 5 w1t some mucus, is to lubricate the surface of tho eye; and. a secondary one, as some believe, is to k op the nostrils damp, so that the inhaled air may be moist,21 and likewise to favour the power of smelJino-. But another, and at least equally important function of tears, is to wash out particles of dust or other 111inute objects which may get into the eyes. That this is of great importance is clear from the cases in which the cornea has been rendered opaque throuo·h inflamn1a~ion, caused by particles of dust not bei~g removed, 1n consequence of the eye and eyelid bccomino· . b n 11nmova le. 22 The . ecretion of tears fron1 the irritation of an! for ign body in the eye is a reflex action;that 1s, the body irritates a peripheral nerve whid1 s nds an impres ion to certain sensory nerve-cells; th s transmit an influence to other coils, and these again 21 n ,rgeon, as quoted in tho 'Journal of Anatomy nnu Pltysiology,' Nov. 1H71, p. 235. 22 . , , for in tance, a case given by Sir Charles Bol1 'Philosophieul Trausactious,' 1823, p. 177. ' |