deposits of urates, nor the transient condition of uricæmia which causes them.

But a last question remains to be solved in order to give a satisfactory explanation of the production of stiffness. Why is it that the nitrogenous wasteproducts which form the deposit of urates, are not formed, the work being equal, in the man in training, just as in the man who performs an exercise for the first time?

There can be but one answer to this question, namely, that in the man who does not exercise his muscles, there exist materials capable of giving rise to these products of incomplete combustion, whereas in the man in training the muscular work has used up these materials, and caused them to disappear. The daily practice of the violent exercise has gradually brought about the disappearance of the reserve materials which were accumulated in the muscles. Work has burned up and dissipated the materials hoarded by inaction.

The reserve materials are only destined to stay a short time in the system; they are provisions of fuel for combustion, and not intended to enter into the intimate woof of the body, and to become an integral part of it. Hence these materials are more easily affected by the process of dissimilation. They resist less the combustions of work; they burn more readily, and are discharged from the organs before undergoing the last stages of oxidation, and remain in the condition of products of incomplete combustion. These waste products, to follow the expression of Bouchard,* are true organic cinders.

The further we examine the facts, the more is this opinion confirmed.

Amateur gymnasts know well, that, in resuming an exercise which has not been practised for a long time, it is impossible to avoid stiffness; but all those who have had occasion to go through this little trial, know that there are two ways of paying tribute. One is, every day

* Bouchara, loc. cit.

to do a small amount of work gradually increased, and thus after a sufficient time to resume the usual quantity of exercise. They feel only slight discomfort after the exercise, and their urine shows only a slight cloud. They come in time to the most violent gymnastic exercises without ever passing through the condition of complete stiffness. This is because they have only produced every day a minimal quantity of the waste products of combustion. These waste products were insufficient to cause any serious disturbance in the system, and not abundant enough to make the urine very turbid. Others prefer to free themselves more quickly and do on the first day all the work they can, exercising their muscles without any stint. There results on the following day severe stiffness and urine loaded with urates. But on the third day, usually, they have recovered all their fitness for exercise, and are quite free from consecutive fatigue. From this time also their urine is free from deposit, and keeps perfectly clear after exercise.

These two different methods lead in the end to the same result; the using up of the reserve materials.

If we seek to establish as clearly as possible the conclusions to be drawn from the facts we have observed, and recorded here, to contribute to the study of consecutive fatigue, we shall be led to formulate two opinions, of which one is an established fact, and the other a very probable hypothesis.

I. We can state as an established fact, the increase in the products of incomplete combustion which form the deposits of urates in all cases in which muscular work is followed by the general disturbances of stiffness, whether febrile or not.

2. We propose as a probable hypothesis which establishes a relation of cause and effect between these phenomena closely united by a constant coexistence; production of nitrogenous waste-products which form deposits of urates, and appearance of the general disturbances of consecutive fatigue. This hypothesis seems to us founded on sufficient deduction to allow us to attribute the stiff

ness of fatigue to a kind of auto-intoxication of the system by the products of dissimilation.

There will thus be a certain analogy between the process of stiffness and that of breathlessness. These two forms of fatigue will be due to the accumulation in the blood of certain products of dissimilation.

The respiratory distress which we call breathlessness is due to the saturation of the blood with a product of dissimilation which is eliminated by the lungs. The general discomfort which we call consecutive fatigue or stiffness of fatigue, must be attributed to the presence in the economy of certain products of dissimilation which are eliminated by the kidney.

We know the product which causes breathlessness; it is carbonic acid.

It is much more difficult, in the present state of our knowledge, to point out the product or products which are the true cause of stiffness. But we can affirm that these products are found among the substances which go to form deposits of urates, and that, among these, uric acid and the urates play an important part in the phenomena of general consecutive fatigue.

CHAPTER VII.

OVERWORK.

Overwork is Exaggerated Fatigue-Different forms of Overwork— Acute Overwork; Death from Breathlessness-Sub-acute Overwork-The Stag hunted to Death-Forced Game; Rapid Cadaveric Rigidity; Prompt Putrefaction-Mechanism of Death by sub-acute Overwork-Auto-Intoxication by products of Dissimilation-Extractives-Lactic Acid-Discoveries of Gautier; Poisons of Living Organisms; Leucomaïnes-Rarity of sub-acute Overwork in Man-The Soldier of MarathonObservations on rapid Cadaveric Rigidity in Men dying in a condition of Overwork — Curious positions of the bodies; Horror-Stricken Expressions in Persons who have been Assassinated-Effects of Overwork on the Flesh of AnimalsDangers of Eating Overworked Flesh-Culinary Qualities given to Flesh in certain cases by Overwork-Suffering a cause of Overwork-Cruelty of a Butcher - Chronic Overwork the form most frequently observed in Man.

I.

OVERWORK is nothing but fatigue pushed to an extremity.

We have seen that excessive work has as its consequence the formation in the system of certain products of dissimilation, and that the general disorders of fatigue are caused by a kind of intoxication of the body by these waste-products, the injurious influence of which is felt until they are eliminated from the body by the excretory organs. In the condition of overwork the organism is no longer able to strive against the too abundant waste-products, which the eliminating organs are incapable of removing. There is a disproportion between the eliminating power of the organism and the great quantity of the products of combustion with which it is encumbered.

Between fatigue and overwork there is simply a difference of dose in the substances which poison the organism; the substances are the same and have the same origin; they are always the waste-products of combustion produced by work.

A man who stops out of breath after running for five minutes is simply a man whose system is under the influence of transient intoxication with carbonic acid resulting from exercise. A horse urged into a very rapid gallop, and forced to run till it drops, dies overworked. The accidents which kill it are due to the carbonic acid gas with which its system is saturated; in the case of the man, the poisonous gas has been eliminated in time; in the case of the horse it has accumulated in quantity sufficient to cause death.

Carbonic acid is, of all the products of combustion, that which is formed most rapidly and in largest quantity during work. It is the most dangerous to the organism; it is the one which causes the man and animal the most pressing dangers. When the organism has the under hand in the contest for its elimination, the fight is always very short, and rapidly fatal. This is what we observe in a horse excited to gallop with insufficient time to breathe, we make it exceed its paces, that is to say, we demand from it a speed out of proportion to the power of its lungs. The animal which exceeds its paces, makes more carbonic acid than its lungs can eliminate.

In

a short time there accumulates in the blood a sufficient quantity to produce the first symptoms of poisoning. If we allowed it to stop, only for a minute, it could, in this short rest, discharge the excess of gas which distresses it, and continue its course without danger. But if we do not give it a moment's breathing space, it retains this excess of carbonic acid, of which the quantity increases every moment, the nerve centres are supplied with blood incapable of maintaining life, the heart-muscle is impregnated with a substance which paralyses it, the circulation stops and the animal dies. Death from breathlessness may be considered as the type of acute over