The time during which the divers can remain submerged is variously stated, and no doubt it differs greatly according to the constitution of the individual. Some observers declare that, in their experience, it never exceeded fifty seconds; but Captain Percival, in his work on Ceylon, gives two minutes as the usual time of remaining under water.[10] Serious effects are produced by this employment, and the divers may frequently be seen with blood issuing from their mouth and nostrils. Yet this does not hinder them from going down in their turn. They will make from forty to fifty plunges in one day, and bring up on each occasion about one hundred oysters. Their day closes before noon; for, as soon as the sea-breeze sets in, the signal is given for the return of the boats to the shore. Their owners, and a large assemblage of persons of all classes, are eagerly looking out for the arrival of the flotilla, and are soon busily employed in examining and stowing away the cargoes. Each owner has a shallow pit fenced round and secured for his own use, in which his store of oysters is deposited, and left open to the air. This pit, or _couttó_, as it is called, is in the midst of a group of huts belonging to the same owner, so that it is under guard of his party. Here the oysters are allowed to putrefy under a burning sun, and a stench arises from them which would seem enough to depopulate the shore of its thousands of inhabitants. Yet such is not the case. The health of the people does not appear to be materially affected, and the oysters are allowed to remain till dry, when they can be easily opened and the pearls extracted. To open them when fresh would require much greater force, and would be likely to injure the pearls. When the putrefaction is sufficiently advanced, the oysters are taken from the _couttó_, and placed in troughs made of the trunks of trees. Sea-water is thrown over them: they are easily opened, and render their pearls to the washing and shaking of a number of men who stand all on one side of the trough, while inspectors at each end closely watch their proceedings, and other inspectors examine the shells which are thrown away, lest they should contain some of the precious substance. The workmen engaged in washing pearls dare not lift their hands to their mouths under penalty of a flogging, yet a man will sometimes contrive to swallow a pearl of high price. After all the pearls are washed out, the largest are carefully picked out from the sand at the bottom of the troughs and washed repeatedly in clean water: the next in size are spread out on white napkins to dry in the sun. The remainder are left to the care of women, who pick them up and dry them. Pearls are assorted by means of three sieves placed one above another, the meshes in which are smaller as the pearls descend. Thus the pearls which will not pass through the uppermost sieve are of the first class, and so on with the others. Another