Robert Hooke read Letter 23 of 1678-01-14

January 27, 1678

Birch, History, vol. III, p. 374, 17 January 1677/8 (O.S.) in London:

Mr. Hooke produced a letter from Mr. Leewenhoeck, mentioned by him at the last meeting to have been received, part of which being translated out of Dutch into English was now read by Mr. Hooke, containing Mr. Leewenhoeck's thanks to the Society for their so kind acceptance of his last communications, and his compliance with their invitation sent him by Mr. Hooke to communicate such other discoveries as he should make, viz., a further account of divers observations made by him with his microscope since his last letter of 2d January, 1676, N.S. which he had sent to the lord viscount Brouncker, concerning the receipt of which he was very solicitous to be informed. He informed the Society of his farther observations on milk phlegme &c: and that those pipes formerly mentioned by them were found in his own as well as in eels blood: that the globules of the blood contained six lesser wthin them: that both the one and the other were extensible into a great length & would afterwards return into a globular form: that the greater were all of equall size, but the globules of milk were all of different magnitude, some smaller, some greater. He mentioned also an experiment of Dr. de Graff of injecting milk into the veins of a dog, and explained the whitenes of milk by a sort of milky substance made by a gum dissolved in spirit of wine & precipitated with water, which would be filled with small globular atomes & look white.

Dr. Grew remarked, that himself had assigned the same cause of the whitenesse of vegetable milks in his discourse of the anatomy of trunks.

Mr. LEEWENHOECK's letter added, that the globules of phlegm were the same wth those of the blood but tougher & greener, &c.

Part of this letter not being yet translated was referred to the next meeting.