In consequence of your request, I have made several experiments with a view of ascertaining the best method of proceeding in Mr. Isaacks’ business. It was our wish that the same precise degree of heat might be applied in both distillations, and therefore we agreed to place the Retorts in a water Bath, and the Receivers in Water and Ice. But I have found it very difficult to make the water in a Retort boil when it is in a water-bath, and altho I saturated the water of the bath with Salt, in order to make its boiling point higher, still the water in the retort boiled so slowly, as [to] require many hours to distill a small quantity. On this account, Dr. Hutchinson and myself have agreed that we will perform the distillation with two Retorts placed in the same Sand Bath at one time, and altho we Cannot be Certain that the degree of heat applied to each will be exactly the same, yet we expect to be sufficiently accurate. I regret the delay which has unavoidably taken place, but we will now perform the distillation at any time you will be pleased to appoint, and if it shall be thought necessary for Mr Isaacks’ satisfaction, that the Distillation be made in a common still, we will do it a second time with one that is in the College, and will answer very well.—With sentiments of the most profound & sincere respect I am your humble serv,