"I am too good a scientist to believe that anything so complex as human life was meant to be wasted in a scheme where not so much as an atom is lost. Bah, your liver is asleep! Too much work--too much work! The black dog has pounced upon your shoulders!" "I never had an attack of the blues or anything similar in my life, Barstow," Donaldson denied quietly. "You 'll propose smelling salts next." "Then what the devil does ail you?" "Nothing ails me. Can't a man have a few theories without the aid of liver complaint?" "Not that kind. They don't go with a sound constitution. When a man begins to talk of finding no use for life, he 's either a coward or sick. And--I know you 're not a coward, Peter." The man on the couch turned uneasily. "Nor sick either. You are as stubborn and narrow as an old woman, Barstow," he complained. "Living is n't a matter of courage, physical or moral. It suits you--it doesn't happen to suit me, but that doesn't mean that you are well and moral while I 'm sick and a coward. My difficulty is simple--clear; I haven't the material means to get out of life what I want. I 'll admit that I might get it by working longer, but I should have to work so many years in my own way that there would n't in the end be enough of me left to enjoy the reward. Now, if I don't like that proposition, who the devil is to criticize me for not accepting it?" "It's quitting not to stay." "It would be if we elected to come. We don't. Moreover, my case is simplified by circumstances--no one is dependent upon me either directly or indirectly. I have no relatives--few friends. These, like you, would call me names for a minute after I 'd gone and then forget." "You 're talking beautiful nonsense," observed Barstow. "Schopenhauer says--" "Damn your barbaric pessimists and all their hungry tribe!" Donaldson smiled a trifle condescendingly. "What's the use of talking to you when you 'll not admit a sound deduction? And yet, if I said you don't know what results when you put together two known chemicals, you 'd--" There was a look in Barstow's face that checked Donaldson,--a look of worried recollection. "I 'd say nothing," he asserted earnestly, "because I _don't_ always know." For a moment his fingers fluttered over the medley of bottles upon the shelves before him. They paused over a small vial containing a brilliant scarlet liquid. He picked it out and held it to the light. "See this?" he asked. Donaldson nodded indifferently.