Mr. Jackson gives a similar account of the plague at Morocco; and he adds, that daily observations convinced him that the epidemic was not caught by approach, unless that approach was accompanied by an inhaling of the breath, or by tending upon the infected person. With such a discrepance of opinion, we cannot be surprised at this anxiety to impugn the doctrine of those practitioners who maintain, that contagion is not to be dreaded, and that severe sanitary precautions are therefore vexatious and oppressive. If the progress of the disease, say the non-contagionists, depends upon personal contact with infected persons or goods, its ravages would never cease in those countries where no precautionary measures are taken to prevent communication between the infected and the healthy; that in Turkey for instance, where these precautions are not resorted to, there would be no cessation of the malady until it had swept away the whole of the population. To these arguments, plausible as they may appear in theory, it has been replied, that the plague to a certain extent has never ceased to exist in the Ottoman empire, but breaks out occasionally after temporary intermissions. As to the permanence of the diseases it is well known that like all other epidemic or endemic diseases, the plague may also be subject to atmospheric influence and be arrested in its progress without human aid. Sir James M'Grigor illustrates this fact in his "Sketches of the Expedition of the Indian Troops to Egypt." When the disease first broke out in the army, the cases sent from the regiments were from the commencement attended with typhoid symptoms; while those from the Bengal volunteer battalion, and the other corps encamped near the marshes of El Hamed, were of an intermittent and remittent type. The cases that occurred in the cold and rainy months of December and January, were of an inflammatory character, after which, as the weather became warmer, the disease at Cairo, Ghiza, Boula, and the isthmus of Suez assumed the form of a mild continual fever. The plague of London in 1665, was in like manner distinguished by a peculiar constitution of the atmosphere. It has also been doubted whether the plague be contagious in every instance of its appearance. Various persons have inoculated themselves with its virus with impunity, though several were ultimately victims of the bold experiment. In Egypt Dr. White inoculated himself ten times, but died of the disease after the eleventh trial.[16]