Visited by Hennig Brand, the Hamburg merchant who discovered phosphorus
From Collected Letters, vol 2, p. 441.
Brand, who was first a soldier and afterwards a merchant at Hamburg, became engrossed in alchemistic studies. By means of the dry destillation of urine he discovered phosphorus (probably in 1669). At the instigation of Leibniz he was afterwards called to Hamburg, where he prepared phosphorus at a fixed salary. His name is also written Brants.
Brand delivered Oldenburg''s Letter L-057 to Leeuwenhoek.
Letter L-058 of 5 October 1677 to the Royal Society:
On the 11th of September Dr. Brants delivered to me your welcome letter of July 28th ultimo and also Nr. 136 of the Transactions containing my slight observations on the brain, flesh, spinal marrow, moxa and cotton, for which I express my heartfelt thanks. I showed some of my observations to that gentleman and afterwards also to some German gentlemen directed to me by the before-mentioned Mr. Brants. You say in your letter that you wish I would closely examine the skin of Moors, also called negroes
