The contention of archæologists is that cotton culture in Peru may go back to a date as early as 200 A.D. The only criterion for such an assumption rests on the theoretical rate of accumulation of guano deposits, in which mummies, wrapped in cotton, have been found,--calculated at two and one half feet per century. This conclusion is absurd, not only for the stress it lays on the capricious habits of sea-birds, but also for the reason that it fails to take into account the irregularity of the guano deposits, as shown in the Peruvian Government Survey of 1854. No conclusion whatever as to the age of even a single mummy-case can be drawn, owing to certain facts concerning Indian burial customs, recorded by Cieza de Leon in 1553, Ondegardo in 1571, and Cobo, nearly a century later. These travellers state that the Peruvian natives were accustomed to open graves, change the clothes of the dead from time to time, and re-bury them (page 67 ff.). The proof that they told the truth is contained in the report by Baessler, of the X-ray examinations of Peruvian mummy-packs in the Royal Museum at Berlin. One such pack contains "the bones of _four separate individuals_, but of none there were enough to construct even distantly one complete skeleton. Besides, there were some _animal bones_ present" (page 71). This disinterment of bodies, and of course the same confusion of the remains, revealed by the X-ray, was practised by the Indians as late as 1621. Nothing then remains to militate against the linguistic testimony so strongly in support of the conclusion that South American cotton culture is of African origin. Professor Wiener's tentative conclusion that tobacco smoking was of African origin, outlined in his first volume of this series, has been strongly reinforced by a study of the Old-World origin of capnotherapy. "Smoking for medicinal purposes," he says on page 180, "is very old, and goes back at least to Greek medicine. A large number of viscous substances, especially henbane and bitumen, were employed in fumigation, and taken through the mouth, sometimes through the nose, for certain diseases, especially catarrh, toothache and pulmonary troubles. This fumigation took place through a funnel which very much resembles a modern pipe, but by its knot-like end at the bottom of the bowl shows its derivation from the distilling cap of the alchemist's retort." The _bitumen_ corresponds to the _tubbaq_ or _tobbaq_ of the Arab doctors, a name applied to several medicinal plants containing a pungent and viscous juice. One of these plants was known in Spain as _tobbaqah_.