(1) IN a paper by A. Scholtz entitled “Sechs Punkte eines Kegelschnittes” (Archiv d. Math. u. Phys., lxii. pp. 317–324, year 1878) there appears a statement which, after correction of two misprints, runs thus:—

where ξln=ylzn − ynzl. A year or so later there was published a paper by Hunyady with the title “Beitrag zur Theorie des Flächen zweiten Grades” (Crelle's Journ., lxxxix. pp. 47–69), in which it is asserted, again without proof, that

The object of the present note is to formulate and prove a general theorem of which these are cases, and to draw certain deductions therefrom.