With increased muscular work the expenditure is much larger, as is evident from the above. Lavoisier was the first to recognize this important law. Zuntz2 has distinguished himself in this field by many important investigations. This celebrated savant has determined the following values for the calories expended in the occupations of ordinary life:

"Walking on a level road requires between 0.5 - 0.6 calories per kilogram and per 1,000 metres, according to the degree of skill in walking' of the individual. A man weighing 80 kgm., and travelling 75 meters per minute, would therefore use for every 1,000 metres walked about 80 X 0.55 = 44 calories, or 3.3 calories every minute, this being about two and one-half times as much as during absolute rest. If there is a ten-per-cent grade in the road the total amount per 1,000 metres is 44 + 60 = 104 calories, or 104 * 75 / 1.000 = 7.8 calories per minute, 468 calorics per hour; this is about the limit of what a strong man is able to perform for any length of time.

1 Speck: "Experimentelle Untersuchungen fiber den Einfluss der Nahrung auf Sauerstoffvcrbrauch und Kohlensaureausscheidung." Archiv fur Experimentelle Pathologie und Pharmacie, ii., p. 412, 1874.

2 Zuntz: "Bemerkungen zur therapeutischen Verwertung der Muskelthatigkeit." Zeitschrift for diatetische und physikalische Therapie, Bd. v., p. 101.

"On accelerating the gait the consumption increases about 0.0024 calories per 1,000 metres for every metre of increased rapidity between 00-100 metres per minute, above 100 metres in increased ratio.

"In wheeling, according to Leo Zuntz, the hourly increase of consumption over that of absolute rest for a man weighing 70 kgm. is as follows:

If, for instance, an adult should traverse four English miles (6,136 metres), he would consume 6,436 * 44 / 1.000 = 283 calories.

With increased work, under the same diet, a person in a state of physiological equilibrium must lose in weight; the increased consumption of calories is supplied from the body tissue. On the other hand, under the same conditions {i.e., ingestion of the same amount of food), but with marked diminution of the usual amount of work (rest in bed), an increase of bodily weight must follow.

1 Every mechanical impediment, every tenderness in muscles, tendons, or joints, like disturbances of coordination (beginning tabes), increases considerably the calorie consumption in walking.

Expressed in other words, this means that the body normally does not lose any of the food introduced (after deduction of the usual not utilized residue, which almost always represents a constant percentage), and converts all ingested material into energy (heat or power) or into tissues. In the same manner, every effort of the organism Cheat, energy) must be compensated for by calorifacient material, no matter whether it be furnished by the food or by the body itself (in case of abstinence from food).

After these digressions in the realm of physiology let us return to our subject:

II. An increase of bodily weight is often desirable in conditions of emaciation and leanness.

Leanness is met with, although rarely, in persons who are perfectly healthy. These are usually individuals of a vivacious temperament doing a great deal of work and eating only moderately. Such persons are apt to remain lean, and may reach an advanced old age without gaining or losing.

It is quite different with those frequently occurring cases of emaciation, The latter accompanies chronic diseases of various nature, and usually progresses steadily. These patients lead a miserable life, and are usually unable to resist any intercurrent disease, and, though they may live some years, hardly ever reach old age. In the majority of instances they fade away much earlier.

In emaciation, as is evident, it is imperative to counteract it - this, in fact, constituting the main object of treatment. But also the leanness of the healthy, if it is of a high degree, ought to be combated. For these persons are at a great disadvantage as compared with normal people. They have no reserve fat on which they can fall back in time of need. This may be fraught with fatal consequence in supervening acute febrile diseases.

Can leanness and emaciation be successfully combated? This question must be answered in the affirmative. In nearly ninety to ninety-five per cent of all the cases of leanness and emaciation (cancer, of course, excepted), in which I have made an extended trial to raise the bodily weight, 1 have been successful.