TEARS

The fluid which lubricates the come a of the eye, when secreted in exce , forms tears; they are limpid, saline, perfectly miscible with water, and have a slight alkaline reagency, owing to the presence of free soda: their principal saline contents are common salt and a trace of phosphate of soda, and they contain traces of albumen; but the whole solid matter scarcely amounts to 1 per cent. When the lachrymal duct by which the tears are conveyed into the nostrils is obliterated, and they flow over the angle of the eye, they become concentrated by evaporation, and leave an irritating muco-saline crust. The exact nature, however, of the animal matter contained in the tears has not been determined. [s. 1240]