could generate the malady, there are certainly still numerous spots in continental Europe, and even in our own land, where, unfortunately, all these elements of disease are in our own day in full and active operation, without any such specific result following; the alleged causes are present without the alleged effects. In order to attain anything like satisfactory results of the supposed physical causes of leprosy in Great Britain in former times, the whole question would require to be thoroughly investigated in connection with two others, viz., the allied physical circumstances,—_firstly_, of the inhabitants of those countries in which the disease in the same way formerly raged; and, _secondly_, of those districts of the world in which it is still prevalent. It is only by following such a line of inquiry that we could hope, if at all, to separate mere matters of opinion from matters of fact, and at last to obtain, by a kind of reasoning by exclusion, the exact physical condition or conditions of a people that are capable of originating or of spreading this particular species of disease. The difficulty of the problem may be easily appreciated by glancing for a moment at the diversified _geographical localities_ and circumstances under which the tubercular leprosy is known at the present day to appear. In modern times it has been found existing, to a more or less limited extent, in places the most distant and the most dissimilar in regard to temperature, climate, situation, soil, etc., as in Sumatra,[295] under the equator, and in parts of Iceland almost within the verge of the Arctic Circle;[296] in the temperate regions of both hemispheres, as (in the southern) at Hamel en Aarde[297] in the Cape district, and (in the northern) at Madeira[298] and Morocco;[299] in the dry and arid plains of Arabia,[300] and in the wet and malarious districts of Batavia[301] and Surinam;[302] along the shores of Guiana,[303] and Sierra Leone,[304] and in the interior of Africa,[305] Hindostan,[306] Asia Minor,[307] and Asiatic Russia;[308] on the sea-coast, as at Carthagena,[309] and thousands of feet above the level of the ocean, as on the table-land of Mexico;[310] on some of the islands in the Indian,[311] Chinese,[312] Caribbean,[313] and Mediterranean[314] seas, and on the continents of Asia, Africa, and America. CONTAGION AS A CAUSE OF LEPROSY. Most modern pathologists seem inclined to call in question the contagious nature of tubercular leprosy, as it at present exists in different parts of the globe.