The Royal Society read the first part of Leeuwenhoek's long letter of the previous October 9

Date: 
February 1, 1677

Royal Society read the first part of Leeuwenhoek's long letter of the previous October 9 and asked that he "communicate his method of observing." According to Birch's History, vol 3, pp. 332

There was read part of a very long letter of Mr. Leewenhoeck to Mr. OLDENBURG, dated at Delft, 9th October, 1676, which had not been produced before, because it could not be sooner translated into English out of the Low Dutch language, in which it was written. The contents thereof were a great number of observations made by Mr. Leewenhoeck with his microscope, concerning certain little animals found by him in vast quantities in common water, snow-water, well-water, and such water, wherein several sorts of spices had stood infused, both whole and pounded.

It was ordered, that the sequel of these observations should be read at the next meeting; and that the author be desired to commonicate his method of observing.