Item 117 - Letter from Augustus De Morgan

6 pp

7 Camden St. & Town - De Morgan admits all Whewell urges against his 'loose expression - which probably conveyed the idea that I meant a cusp must be a defunct loop - what I ought to have said is, show me a cusp - and I show you its curve as an individual of one family in which a loop dies at the cusp. But then I can show it you as an individual of an infinite number of other families - some of which have that cusp permanently'. You may be able to explain the deviation of a cusp in one family but the difficulty may remain in another. The same thing is applicable with a conjugate point. De Morgan has been 'trying to ascertain that 'from and after' and also 'after' in old English includes the day from which reckoning is made - in opposition to lawyers and others'.