<正> 1. In 1867 Sylvester published a paper in Philos. Mag. with perhaps the funniesttitle ever written in the mathematical literature. The various questions treated hereall led him to the problem to determine for which n-values one can construct a determinantof order n consisting exclusively from±1 and which is orthogonal in the sense that thecomposition of any two different rows is 0. If n is odd, then obviously no such determinantcan exist; Sylvester showed very easily that for n=2~k(k=1,2,…) there are such determinants. If n≥3, then it is easy to show that such a determinator can exist only inthe case n≡0 mod 4. For if it exists such a determinant with the elements a_(μν) then we have