Microscopical observations from Leeuwenhoeck, concerning blood, milk, bones, the brain, spitle, and cuticula, &c. communicated by the said observer to the Publisher in a letter, dated June 1. 1674
Abstract
Sir, Yours of 24th of April last was very welcome to me; Whence I understood with great contentment, that my Microscopical Communications had not been unacceptable to you and your Philosophical Friends; which hath encouraged me to prosecute such observations, concerning which I shall at present impart to you what follows

