The medical attendants are not free from the hurtful operation of this doctrine. If believers in infectious air, they are under a feeling of apprehension which, perhaps with some, may not be strongly felt, on account of the frequency of impunity from exposure; but with many it is strongly felt, and influences their attendance on the sick, their communication with them, and their own comfort and feeling of security. Many instances are known—they are of very frequent occurrence—where the physician, from apprehension, has failed to pay so many visits as were necessary, or to remain with his patient sufficiently long to ascertain his situation, and watch well the progress of the case. Cases are known where patients have been looked at by their advisers, stationed at the door, where it was impossible to ascertain the expression of the countenance, the condition of the tongue, the state of the skin, not to say any thing of that of the pulse. We are acquainted with instances in which medical men have so acted under the apprehension of taking infection, and where, too, they have not felt they were doing any thing reprehensible, as was sufficiently evident from the fact, that they themselves were the informants. These facts prove that injury has been done to the patient from insufficient care; and cases are not wanting, where medical men themselves have taken disease, where the circumstances of the case warranted the belief that fear was the chief, if not the only cause. Many very cunningly-devised plans have been recommended for the adoption of the physicians visiting patients labouring under infectious diseases, such as standing in a current of air passing between windows, or doors and windows,—keeping a handkerchief applied to the mouth and nose, washing the mouth with water, &c. These are sometimes adopted, yet there is room to think that, where a man of merely ordinary fortitude supposes that he inspires an atmosphere holding in solution a very virulent, nay deadly poison, that he will be anxious to make his visit as short as possible, even though the preventives above mentioned be religiously adopted. Several of the cases of death among medical men, which have been unhesitatingly attributed to infectious air, the Author is convinced, from his knowledge of particular circumstances, and from the known tendency of fear, have arisen from depression, in consequence of that passion. The prejudicial operation of the doctrine of infectious air has been proved in reference to the patient himself, _1st_, From his apprehension for the safety of others ministering to him; _2d_, From the neglect and desertion of friends and others; _3d_, From the insufficient medical treatment which his case frequently obtains.