Meph. Nachher vor alien andern Sachen Müsst ihe euch an die Funktionen-Theorie machen. Da seht, dass ihr tiefsinnig fasst, Was sich zu integrieren nicht passt. An Theoremen wird’s euch nicht fehlen, Müsst nur die Verschwindungspunkte zählen, Umkehren, abbilden, auf der Eb’ne ’rumfahren Und mit den Theta-Produkten nicht sparen. --LASSWITZ, KURD. _Der Faust-Tragödie (-n)ter Tiel; Zeitschrift für den math.-natur. Unterricht, Bd. 14 (1883), p. 316._ Fuchs. Your words fill me with an awful dread, Seems like a circle were squared in my head. Meph. Next in order you certainly ought On function-theory bestow your thought, And penetrate with contemplation What resists your attempts at integration. You’ll find no dearth of theorems there-- To vanishing-points give proper care-- Enumerate, reciprocate, Nor forget to delineate, Traverse the plane from end to end, And theta-functions freely spend. =1935.= The student should avoid _founding results_ upon divergent series, as the question of their legitimacy is disputed upon grounds to which no answer commanding anything like general assent has yet been given. But they may be used as means of discovery, provided that their results be verified by other means before they are considered as established.--DE MORGAN, A. _Trigonometry and Double Algebra (London, 1849), p. 55._ =1936.= There is nothing now which ever gives me any thought or care in algebra except divergent series, which I cannot follow the French in rejecting.--DE MORGAN, A. _Graves’ Life of W. R. Hamilton (New York, 1882-1889), Vol. 3, p. 249._ =1937.= It is a strange vicissitude of our science that these [divergent] series which early in the century were supposed to be banished once and for all from rigorous mathematics should at its close be knocking at the door for readmission.--PIERPONT, J. _Congress of Arts and Sciences (Boston and New York, 1905), Vol. 1, p. 476._