We have known many persons much affected with the fear of taking infection, and allowing this to prey upon their spirits, who were among the first attacked with pestilence; and if any weight is to be given to our knowledge of the probable causes of disease, there is great reason for concluding that those persons were the victims of their very fears, more than of any other causes of a prejudicial character. It is often impossible, with complete justice, to say decidedly that any one influence has been the exclusive cause of disease, when there is room to think there are, or may be many ready to operate; but, in many instances, the relation has been so immediate, and so striking between the known presence of depressing apprehension, and the supervention of sickness, that there is no room left to doubt the propriety of placing them in the relation of cause and effect. It must be familiar to many, quite a common occurrence, and one of which we heard constantly during the ravages of Cholera a few years ago, that persons took that disease from mere fright, and of the attack having been very much encouraged by its operation among the attendants, and more especially of those believing in the existence of the infectious nature of the disease. These facts, it is thought, will prove that the doctrine of Atmospheric Contagion is calculated to excite much apprehension among the attendants and visitors of one sick of pestilence, and to shew in what manner that very apprehension is disposed to produce disease. The attendant or visitor persuaded of the atmospherically contagious character of the disease, must possess considerable fortitude to venture at all into the presence of the patient, and even when once there, he must possess more than common hardihood, who does not feel more or less depressed with apprehension for that potent, and not the less imposing agent, because invisible, which, like a drawn sword, hangs over him, and threatens his existence. By the belief in the doctrine of Atmospheric Contagion, the attendant not only becomes, in general, exposed to one of the most common and efficient causes of disease, viz. fear, but his offices are performed more as a duty than as a gratification, which it is to a well disposed mind, where no extraordinary danger is encountered, and he is thus forced to make a sacrifice of his feelings, and the valued assurance of security to a rigid sense of duty; but however much such conduct may agree with morals, it is detrimental to health.