In many nervous affections albumen may be found in the urine. It can be produced, as was shown long ago by Bernard, by a puncture in the floor of the fourth ventricle near to the point where a similar puncture gives rise to diabetes. Lesion of the cerebral peduncles, section, destruction, or irritation of the spinal cord, and irritation of the renal nerves are also causes of this symptom. It is by no means difficult to account for this phenomenon by the changes which take place in the {41} renal circulation under influence of the vaso-motor nerves which originate or pass through the peduncles, pons, and spinal cord, although it is highly probable that similar results might follow irritation transmitted from a distance. These facts are not without practical importance, for they give rise to very considerable chances of error in diagnosis; as, for instance, where a patient suffering from severe headache, with possibly gastric symptoms, is found to have albumen and casts in his urine, which is also copious and of low specific gravity. It might not be easy to decide that such a case was not one of interstitial nephritis with symptoms far from unusual, and yet it might perfectly well be a cerebral tumor. The diagnosis would demand a thorough search for other symptoms, such as double optic neuritis on the one hand, as indicating cerebral disease and cardiac hypertrophy, with high arterial tension on the other, as connected with nephritis. A careful consideration of the order of their occurrence is also desirable. After an epileptic attack albumen may appear in the urine for a short time, disappearing within a few hours. This occurrence might lead to an erroneous diagnosis of uræmic convulsions if the examination happened to be made shortly after a fit and not repeated at a later period. Transitory mania may perhaps be placed in the same category. Chronic mental disease, like general paralysis of the insane, is frequently accompanied by albuminuria, and even temporary mental disturbance in a sensitive person has been known to excite the symptom. In narcotic poisoning both by alcohol and by opium a similar state of things sometimes occurs. With alcohol, however, distinction is to be made between chronic cases, where a suspicion of parenchymatous nephritis may be fairly entertained, and acute alcoholism or delirium tremens, where the albumen appears and disappears within a few days. In a patient profoundly under the influence of opium the urine may contain not only albumen, but casts, and the diagnosis of uræmic coma is very likely to be made if nothing is known about the history--an error which might be of great consequence, as tending to discourage the efficient treatment necessary in opium-poisoning or causing the waste of time on inefficient measures.