A catalyst is a substance which alters the velocity of a chemical reaction without appearing in the final products.

The chemists work with inaccurate and poor measuring services, but they employ very good materials. The physicists, on the other hand, use excellent methods and accurate instruments, but they apply these to very inferior materials. The physical chemists combine both these characteristics in that they apply imprecise methods to impure materials.

Non-aqueous solutions don't conduct.

The only difference between elements and compounds consists in the supposed impossibility of proving the so-called elements to be compounds.

Happiness is equal to work minus resistance.

A catalyst is a substance which alters the velocity of a chemical reaction without appearing in the final products.

I must consider the organizer as more important than the discoverer.