“In the year 1657 I discovered very small living creatures in rain water.”

There was discover’d by me a fifth sort, which had near the thickness of the former, but they were almost twice as long. The first time bacteria were observed.

The 4th sort of creatures… which moved through the 3 former sorts, were incredibly small, and so small in my eye that I judged, that if 100 of them lay [stretched out] one by another, they would not equal the length of a grain of course Sand; and according to this estimate.

I make the proportion of one of these small Water-creatures to a Cheese-mite, to be like that of a Bee to a Horse:

Among other things, I saw in the body of one of these animalcules a bright and round corpuscle, placed near the head, and in which a very wonderful swift motion was to be seen, consisting of an alternate extension and contraction.

[M]y work, which I’ve done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men.

In it, that sometimes more than a thousand were moving about in an amount of material the size of a grain of sand…

Whenever I found something remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people be informed thereof.

Man has always to be busy with his thoughts if anything is to be accomplished.

In the year 1657 I discovered very small living creatures in rain water.

And I judge that some of these little creatures were above a thousand times smaller than the smallest ones I have ever yet seen, upon the rind of cheese, in wheaten flour, mould, and the like.

I’ve spent more time than many will believe [making microscopic observations], but I’ve done them with joy, and I’ve taken no notice those who have said why take so much trouble and what good is it?

The 31th of May, I perceived in the same water more of those Animals, as also some that were somewhat bigger.

And therewithal, whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof.

This particle I concluded to be the heart.

For, the circumference of one of these little Animals in water, is not so big as the thickness of a hair in a Cheese-mite.

And I imagine, that [ten hundred thousand] of these little Creatures do not equal an ordinary grain of Sand in bigness: And comparing them with a Cheese-mite (which may be seen to move with the naked eye)

We can discover this meaning in life in three different ways: 1. by doing a deed; 2. by experiencing a value; and 3. by suffering.

What one man can invent, another can discover.

I believe myself to possess a most singular combination of qualities exactly fitted to make me pre-eminently a discoverer of the hidden realities of nature.

Imagination is the Discovering Faculty, pre-eminently. It is that which penetrates into the unseen worlds around us, the worlds of Science.

Only when we are brave enough to explore the darkness will we discover the infinite power of our light.

I am one of those who think like Nobel, that humanity will draw more good than evil from new discoveries.

We must not forget that when radium was discovered no one knew that it would prove useful in hospitals.

Travelling opens up our minds & helps us discover ourselves.