HIS IMPERIAL MAJESTY, MOHAMMED ALI, SHAH OF PERSIA Wearing the Kajar crown ] The anatomist Diemerbroeck relates[113] the case of a pearl diver who, under his own observation, remained half an hour at a time under water while pursuing his work; and this was seriously adopted without comment by John Mason Goode in his “Study of Medicine.”[114] Ibn Batuta, “the Doctor of Tangier,” wrote about 1336 that “some remain down an hour, others two hours, others less.”[115] A still earlier writer, Jouchanan ibn Masouiah,[116] in his book on stones, states that “the diver, when he dives, places upon his nose a _masfâsa_ lest water should enter into him, and breathes through the fissure, and remains under water for half an hour.” According to Sebaldus Rau[117] this _masfâsa_ was an article resembling a hood or cap, which the diver placed over his nose. It was made of some impervious material and had a projection so long that it reached to the surface of the water. The same writer believes that this object was alluded to by Aristotle (“De part. animal.,” _Lib._ II, c. 16), where he likens the trunk of the elephant to the instrument used by certain divers for aiding their respiration, so that they could remain longer in the water and draw in air from above the surface.[118] And here we cease pursuit of further records, lest our faith in recorded testimony be too severely tested.[119] A superficial inspection of the above evidence, from the one or two hours noted by Ibn Batuta about the year 1336, to the half an hour of Diemerbroeck in 1672, the quarter of an hour of Vernatti in 1669, the seven and one half minutes of Chardin in 1711, the six minutes of Percival in 1803, to the 110 seconds of the present time, seems to indicate very clearly a gradual but somewhat remarkable decrease in the ability of the Asiatic divers, and that the pearl fishermen of the present day are very different creatures from their ancestors. And especially is this so when it is considered that the above records are not isolated reports selected for the particular purpose of showing a decrease in the length of diving; on the contrary they are authoritative and representative publications of their respective periods. We do not recall having seen in any report issued previous to 1675, an intimation that the limit of time was less than ten minutes.