soil poisons. Bubo-plague also is a soil poison; and it is claimed as specially related to the products of _cadaveric_ decomposition, diffused at large in such a soil as soil-poisons are ordinarily engendered in. It is possible to subject that theory of the plague to the test of facts still further. Thus bubo-plague dogged the steps of Mohammedan conquest from the first century after the Hegira, now in Syria when Damascus was the capital, now in Irak when Bagdad was the centre of Mohammedan rule, now in Egypt when the seat of empire shifted to Grand Cairo; and, over a great part of the period, simultaneously in all the regions of Islam. That long series of plague-epidemics has been recorded in Arabic annals, and has lately been published in an abstract accessible to all, with a summary of conclusions[306]. What are the conclusions of the learned commentator on the Arabic annals, as to the general causes of the thousand years of Mohammedan plague?--“War, with the wasting of whole nations, in disregard of all established rights, with plundering of towns and concentration of great masses of men ill provided for and unregulated, who developed the seeds of communicable and malignant diseases. Add to these things the negligent or wholly neglected burial of those who had fallen in battle, the straits and privations of the wounded, and the effects of a hot climate, especially in flooded and swampy tracts of country.... The kind of burial, in very shallow and often badly covered graves, which used to be practised in most Eastern towns, and in part is still practised, may also have had disastrous consequences not unfrequently.” The Theory tested by Modern Instances.