pastor Petrus Gribius wrote to James Jurin of the Royal Society about Leeuwenhoek's methods

Date: 
October 4, 1723

"What is true in natural philosophy can be most fruitfully investigated by the experimental method, supported by the evidence of the senses."

Dobell's Little Animals (pp. 97) has a translation of the whole letter from the Latin:

In our present scientific age, the blessed Antony van Leeuwenhoek considered that what is true in natural philosophy can be most fruitfully investigated by the experimental method, supported by the evidence of the senses; for which reason, by diligence and tireless labour he made with his own hand certain most excellent lenses, with the aid of which he discovered many secrets of Nature, now famous throughout the whole philosophical World: of which sacred apparatus he bequeathed no contemptible a share, inclosed by himself in this little cabinet, to the Royal Society, with no other object than to afford those ingenious and most erudite men a token of his veneration, and as a mark of his gratitude for having been enrolled among their learned Company.

His Daughter (a spinster of excellent repute, who has preferred a single life to matrimony, in order that she might ever continue to attend her father) earnestly begs this one favour: that you disdain not to send back word that this little present hath not gone astray, but is come safe into your hands; which I likewise fully trust was the lot of my own letter written to you, in no joyful spirit, five weeks ago.

I pray God, most illustrious Sir, that He suffer you long to continue shining as a great and singular light and star of the first magnitude to Philosophy.

Document: 

ms. Royal Society, no. 1215; G.2.4