From Doctor Willan, London.

August 6th, 1798. 

A Gentleman about 25 years of age, tall and thin, has been engaged in a fatiguing, though sedentary occupation, but always conducted himself with sobriety and regularity. For more than a year past he had found his health and strength gradually declining ; he became pale, emaciated, and skeletal; his hands and feet were unusually dry and hot; he had sometimes a trifling cough, and was affected with a great shortness of breathing, on going up stairs, or any ascent. 

The case being deemed consumptive, he had been recommended to confine himself to a vegetable diet, and to spend as much time as possible in the country. This plan, however, was not attended with any tangible benefit: on the contrary, the wasting and general debility seemed to be daily increasing under it. 

I did not see this young Gentleman till the middle of May last. In addition to the symptoms above mentioned, he then complained of a clamminess in the mouth, a parched tongue, and an unquenchable thirst. His pulse was from 76 to 86, weak, and unequal. He was in general very costive. From these circumstances, I was induced to examine the state of the urinary secretion, before anything was administered to him medicinally.

The result of the first trial was as follows. He took in 24 hours 11 pints of fluid, consisting of milk, or milk and water, with two slices of toasted bread, and within the same time made 12 pints of urine, a portion of which was evaporated by Mr. Moore, of Apothecaries Hall; the result will be subjoined. The urine was of the highest straw colour, had a faint disagreeable smell, and was sweetish to the taste. His breath had, at this time, an unpleasant acidulous smell, nearly the same as that produced by the effluvia of decaying apples. He observed to me, that for several days past he had felt a pain in the head, and a stiffness, or drawing in of the eyes, with imperfect vision, the letters appearing double whenever he attempted to read or write. 

A total change of diet seemed the only means of preserving this worthy young man from almost immediate dissolution. He commenced the plan without hesitation, abstaining wholly from bread, or other vegetable substances, and from all fermented liquors. For breakfast he took milk, with yolk of egg; for dinner, occasionally fish, but, in general, beef or mutton which had been long kept, sometimes a little ham; for supper, a poached egg, or calve's foot jelly, prepared without wine or acid. 

On the eighth clay of this course, a second examination was made of the state of the urine, which amounted only to 2 pints in 24 hours, 3 pints of milk, or tnxlk and water, having been drank within the same time. The urine was more high coloured than before, but had not wholly lost its faint smell. A third trial of the same kind was made on the 10th of June. He drank 3 pints of fluid, and made exactly the same quantity of water. It must, however, be remarked, that the day was extremely chilly, and that he did not ride out, nor take any exercise through the whole of it. 

On the 12th of June, he informed me that his thirst was nearly removed, but that he felt a soreness of the stomach, and great oppression of it after eating, with sickness. These symptoms continued the three following days, which he spent in the country, and then ceased. From that time his stomach became reconciled to animal diet; his appetite and strength increased; he eat with a proper relish, and was not troubled with thirst. 

On the 18th of June he drank 3 pints of liquid, and discharged only 2.75 pints of urine, which had the usual smell and colour. He stated that he had begun to perspire at night, which had not been the case for some time before; alfo, that he felt his hands and feet more moist and comfortable. The complaint of his head and eyes was likewise removed.

June 20th his pulse was more firm; and he found himself recovering strength, so that he could walk a mile or two without fatigue. He eat heartily, slept well, and seldom drank between meals.

On the 12d June some family concerns obliged him to set off for Yorkshire. He went, however, with the resolution of adhering to the plan of diet which had already so much relieved him, without the use of any medicine, excepting a little castor oil, as an occasional laxative. On Saturday Iast, August 4th, in a letter, he informed me, that he bore the journey very well ; but that fome fatigue, and agitation of mind since, had much depressed, and enfeebled him. From this state, however, he recovered in two or three weeks; and he is now able to take considerable exercise either by walking or on horseback. He hopes to be in town soon, and thinks himself qualified to undertake business with as much activity as usual.