The effect of this upon his scientific labors I have indicated earlier. It hampered them at every step. He could work but a few hours in the morning and after that the constant effort and lesson was in the endeavor to forget; ‘It is so weariful, killing the whole afternoon, after 12 o’clock, doing nothing whatever.’[258] A piece of investigation, which required perhaps the most nice and constant watchfulness, had to be abandoned in the middle, because recurring and increasing symptoms absolutely demanded that complete rest should be taken. It was necessary not only to stop working, but to stop thinking, and for a brain eager and absorbed as Darwin’s was, this was enormously difficult. With social life the limitation was equally vexatious. It is true that there are certain compensations about such a state of things. A successful and prominent man who has his health is expected to meet all sorts of social demands and strains which consume his time to little purpose, and if he is not extremely careful of himself and does not sometimes push insistence even to the point of rudeness, he finds his work interfered with almost as much as by ill-health, or it may be even more. There are many times when delicate health is a convenient and useful excuse, and Darwin recognized this very fully: ‘Even ill-health, though it has annihilated several years of my life, has saved me from the distractions of society and amusement.’[259] But the compensation was not always appreciated. When indigestion preserved you from boredom, you might be grateful; but when it cut you off from seeing your best friends, when it deprived you of that exchange of scientific ideas which is the keenest and most fruitful stimulus for achievement, then you could not but repine a little. The excitement, the enthusiasm of eager talk, made you forget yourself and your symptoms for the time. But there was the inevitable afterwards, and gradually you learned that restraint was necessary. ‘Even talking of an evening for less than two hours has twice recently brought on such violent vomiting and trembling that I dread coming up to London.’[260] Simple comments like this, often repeated, show how intense and how crippling the weakness was. What is notable about this matter of Darwin’s ill-health is that it bred no bitterness. There is an occasional sigh of regret, a touch of humorous complaint over the deprivations and the inability to accomplish all that was desired: ‘Adios, my dear Hooker; do be wise and good, and be careful of your stomach, within which, as I know full well, lie intellect, conscience, temper, and the affections.’[261] But there is not one trace of that sour pessimism, that crabbed outcry against the dispositions of Providence and of the universe which chronic invalidism is so apt to produce.