Again, my hypothesis explains the fact that inspiration, save under extraordinary circumstances, is never continuous for more than a relatively short period. A banker, a barber or a manufacturer of patent medicines does his work day after day without any noticeable rise or fall of efficiency; save when he is drunk, jailed or ill in bed the curve of his achievement is flattened out until it becomes almost a straight line. But the curve of an artist, even of the greatest of artists, is frightfully zig-zagged. There are moments when it sinks below the bottom of the chart, and immediately following there may be moments when it threatens to run off the top. Some of the noblest passages written by Shakespeare are in his worst plays, cheek by jowl with padding and banality; some of the worst music of Wagner is in his finest music dramas. There is, indeed, no such thing as a flawless masterpiece. Long labored, it may be gradually enriched with purple passages--the high inspirations of widely separated times crowded together--, but even so it will remain spotty, for those purple passages will be clumsily joined, and their joints will remain as apparent as so many false teeth. Only the most elementary knowledge of psychology is needed to show the cause of the zig-zagging that I have mentioned. It lies in the elemental fact that the chemical constitution of the blood changes every hour, almost every minute. What it is at the beginning of digestion is not what it is at the end of digestion, and in both cases it is enormously affected by the nature of the substances digested. No man, within twenty-four hours after eating a meal in a Pennsylvania Railroad dining-car, could conceivably write anything worth reading. A tough beefsteak, I daresay, has ditched many a promising sonnet, and bad beer, as every one knows, has spoiled hundreds of sonatas. Thus inspiration rises and falls, and even when it rises twice to the same height it usually shows some qualitative difference--there is the inspiration, say, of Spring vegetables and there is the inspiration of Autumn fruits. In a long work the products of greatly differing inspirations, of greatly differing streams of blood, are hideously intermingled, and the result is the inevitable spottiness that I have mentioned. No one but a maniac argues that "Die Meistersinger" is _all_ good. One detects in it days when Wagner felt, as the saying goes, like a fighting cock, but one also detects days when he arose in the morning full of acidosis and despair--days when he turned heavily from the Pierian spring to castor oil.