Newton's notation for differentiation, or dot notation, uses a dot placed over a function name to denote the time derivative of that function. Newton referred to this as a fluxion. (See Article 567 of Florian Cajori's book on A History of Mathematical Notations.)
and so on.
Dot notation is not very useful for higher-order derivatives, but in mechanics and other engineering fields, the use of higher than second-order derivatives is limited.
- Newton's original papers and notebooks showing the development of his work, Cambridge University Digital Library
- Cajori, Article 567
Florian Cajori, A History of Mathematical Notations, Dover Publications, Inc. New York. ISBN 0-486-67766-4