Instances, Hints, and Applications, Relating to a Main Point, Solicited in the Preface to this 4th Vol; Concerning the Use May be Made of Vaults, Deep Wells, and Cold Conservatories, to Find out the Cause, or to Promote the Generation of Salt, Minerals, Metals, Christal; Gems, Stones of Divers Kinds; And Helps to Conserue Long; Or to Hasten Putrefaction, Fertility of Any Land, &c. by the Same D. Beale, in Another Letter to the Publisher