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Oft reaching the internal angle of the palpebrae, the tears accumulate its 

 the lacus lachrymalis, a small space formed between the edges of the pal- 

 pebrae, kept separated from each other by the caruncula lachrymalis. 

 This last substance, long considered by the ancients as the secretory organ 

 of the tears, is merely a collection of mucous cryptae covered over by a 

 loose fold of the conjunctiva. These follicles, alike in nature to the mei- 

 bomian glands, secret like them, an unctuous substance which smears the 

 rnoveable edges of the pa'lpebrse, near the internal commissure. The 

 edges of the eye-lids, in this situation, require a thicker coating, as the 

 tears accumulated in that spot have no where a greater tendency to flow 

 on the cheek. 



Near the union of the inner sixth of the free edge of the palpebras 

 with the remaining five-sixths, at the outer part, where their internal, 

 straight, or horizontal portion unites with the curved part, there are situ- 

 ated two small tubercles, at the top of each of which there is a minute 

 orifice. These are the puncta lachrymalia, and they are called superior 

 and inferior, according to the palpebrse to which they belong. In the 

 dead body, the puncta do not appear to be tubercular, the small bulgings 

 produced, doubtless, by a state of orgasm and of vital erection, collapse at 

 the approach of death. These small apertures, directed inward and back- 

 wards, are incessantly immersed in the accumulated tears, absorb them and 

 convey them into the lachrymal sac, by means of the lachrymal ducts of 

 which they are the external orifices. The absorption of the tears, and 

 their flow into a membranous reservoir lodged in the groove formed by the 

 os unguis, do not depend on the capillary attraction of the lachrymal 

 ducts 5 each of them, endowed with a peculiar vital action, takes up, by a 

 real process of suction, the tears accumulated in the lacus lachrymalis, 

 and determines their flow into the sac. The weight of the fluid, the 

 effort of the columns which succeed each other, co-operate with the action 

 of the parietes of the duct. The flow of the tears is further facilitated by 

 the compression and slight concussions attending the contractions of the 

 palpebral fibres of the orbicularis, behind which the lachrymal ducts are 

 situated. This vitality of the puncta lachrymalia and of the ducts is rea- 

 dily discovered, when we attempt to introduce into them Anel's syringe or 

 Mejean's stylet, to remove slight obstructions of the lachrymal passages, 

 In a child now under my care, fora mucous obstruction of the nasal duct, 

 I can see the puncta lachrymalia contract, when the extremity of the 

 syphon does not, at once, enter the canal. One is then obliged to wait, 

 before it can be introduced, for a cessation of the spasmodic contraction, 

 sac, which lasts but a few moments. The tears which which flow into 

 the lachrymal by the common orifice of the united puncta lachrymalia, 

 never accumulate within it, except in case of morbid obstruction; they, 

 in that case, at once enter into the nasal duct, which is a continuation of 

 it, and fall into the nasal fossae, below the anterior part of the inferior 

 turbinated bones of these cavities. There, they unite with the mucous 

 of the nose, increase its quantity, render it more fluid, and change its 

 composition. The use of the tears is to protect the eye-ball against the 

 irritating impression of the immediate contact of the atmosphere. They, 

 at the same time, favour the sliding of the palpebrae, lessen the friction 

 in those parts and in the eye-ball, and thus promote their motion. 



CXVIII. Of the globe of the eye. The eye-ball, as was already ob- 

 served, may be considered as a dioptrical instrument placed before the 

 retina ; whose office it is to refract the luminous rays, and to collect them 



