The important point is not the bigness of Avogadros number but the big — Chemistry

"Be a physical chemist, an analytical chemist, an organic chemist, if you will; but above all, be a chemist"

"The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and vapour, soot and flame, poisons and poverty; yet among all these evils I seem to live so sweetly that may I die if I were to change places with the Persian king."

"Like a chemist, Napoleon considered all Europe to be material for his experiments. But in due course, this material reacted against him."

"Never before has mankind had to face the possibility of extinction in all-out fusion bomb war, nor has it had occasion for hope of unexampled prosperity in the taming of that same fusion bomb. Either fate could result from a single branch of scientific advance. We are gaining the knowledge; science is giving us that. Now we need wisdom as well."

"If we could determine the nature of substances burning at Mannheim, why should we not do the same with regard to the sun? ---But people would say we must have gone mad to dream of such a thing."

"Its name [alchemy] will no doubt prevent its being acceptable to many; but why should wise people hate without cause that which some other wantonly misuse? Why hate blue because some clumsy painter uses it? Which would Caesar order to be crucified, the thief or the thing he had stolen? No science can be deservedly held in contempt by one who knows noting about it. Because you are ignorant of alchemy, you are ignorant of the mysteries of nature."