“…Although we started to organize QSARs with a view to making comparative studies some time ago, , it is only with the development of highly effective interactive computing and Internet for the exchange of data that a serious attempt can be made to organize what has been learned about QSAR since Hammett's initiation of the use of σ constants in 1935. The only attempt to list all Hammett equations was made in 1953 by Jaffe who organized some 400 examples.…”