The first effect of these xanthins is to act as acids, and clear the blood of uric acid, hence they are stimulants; later they come into the blood as uric acid and increase the depression.

Practically those, who cannot get through their daily work without calling out their reserves with alcohol or tobacco, the action of which I have considered in "Uric Acid," are weak or diseased, and are entering on the road to physiological bankruptcy. And who are the people that are thus constantly calling on their reserves? Not those that live on the diets in the above Tables, far from it, for those who go on these diets commonly give up alcohol and tobacco, if they used them before when on other diets.

It is the flesh eaters who want the stimulants, and the reason is simple, for on all flesh diets they are constantly taking those terrible poisons, uric acid and the xanthins, and these are first stimulants and afterwards depressants; they first unnecessarily call out the reserves and then plunge all into depression and feeble nutrition, by blocking the circulation; and while this is going on other stimulants, as alcohol and tobacco, or tea, have to be called in to keep things going (see also p. 40).

It follows that the only way to get clear of stimulants is to give them up altogether; if you keep on any of them you must be led to take more and more, and gradually to add others which are more powerful.

On the other hand, to live on one's income, to have one's reserves entire and untouched for that evil day of trial which is sure to come to all, to work calmly and steadily without fuss and without friction is alone sufficient to make life worth living; and so great is the difference between physiological solvency and physiological bankruptcy, that I do not exaggerate when I say that the knowledge of how to attain to the former has repaid me a thousand times over for all the time and trouble expended on experiments. Then, again, the physiologically solvent know to the full the joys of a strong and useful life, while the bankrupt knows these joys but once, in the memory of what he was before he began to call on his reserves, and as these reserves get smaller and smaller, the stimulants, even the more powerful ones, such as morphine and cocaine, which he eventually calls in, fail ever more and more to bring him even for a moment to the level of physiological health, which the solvent man enjoys continually.

But the difference must be felt and cannot really be described, and I know also that there are conditions of ignorance combined with prejudice, which are too deep for words, and on which mere words produce no more effect than water on the back of the proverbial duck, and that the people living under these conditions may for practical purposes be divided into those who do not know and those who do not want to know.

Now the case of the latter is at once hopeless; but for those who are simply ignorant, and have no objection to knowledge if they can obtain it, a demonstration, which is far more powerful than words, can always be obtained by putting in force the calculation of albumens for body weight and watching the result for themselves. It will not do to measure milk by the cupful, or to imagine that an ounce of cheese is no larger than a hazel nut; these foods must be measured and weighed at first, till the proper quantity comes to be accurately known at sight.

Then part, at least, of the bona fide doubts of the ignorant may be due to the fact that numbers and numbers of people, who call themselves "vegeor others who for one reason or another have abjured flesh as food, have had no real physiological knowledge, and have only too often quite failed to put an adequate quantity of albumens in place of those they left off: the result has been that their nutrition has often failed either to quite satisfy themselves, or to commend their methods to others.

Here, also, probably originates the doubt, one not infrequently hears expressed, as to whether patients can "stand" the diet. I can only say that the great majority of people I see have no difficulty in digesting most of the foods enumerated in the above Tables; and that if they take sufficient of these, and digest them, they need have no anxiety, either about nutrition or strength, and they are likely to find their powers of endurance much increased.

No doubt those whose bodies are full of urates, as the result of years of flesh diet and tea, are likely to get pale at first on the new diet, as it will bring a large quantity of uric acid into their blood on its way to be eliminated; but this is merely the evil of the old diet being brought out, and if they persevere they will in 12-18 months have a better colour than most meat-eaters, as the uric acid having been eliminated, their blood will recover and improve (See "Uric Acid," chapter xii.).

And I have found the colour and condition of the blood such a useful guide to the effects of treatment, that I have been led to produce a card of colours,1 for the approximate estimation of the blood decimal from the corresponding colour of the mucous membranes of the patient.

Thus a patient whose colour, as seen in tongue, gums, or eyelids, corresponds to that marked 4 on the card, may, at the end of three months on diet, be the same, or the colour may have fallen to 3, or improved to 5 (these being intermediates between 2 and 4, and 4 and 6).

If he is the same I am content, as the blood does not improve much at first on diet; if he has improved to 5 he has done more than usually well, but if he has fallen to 3 he has done badly, and the uric acid of the old diet has been rushing too much into his blood, and the rush requires to be moderated. I then investigate the matter and probably find that he has not been taking enough food, or has not been digesting what he takes, or that he has been over-tiring or over-working himself, or living in a hot, relaxing climate, any of which would increase the rush of the uric acid into the blood, and I then proceed to adjust the diet better, or to give a tonic to hold back the uric acid flood for a little.