VI. Affidavit of the Secretary of State on the Result of the Experiments
Philadelphia March 26. 1791.
Department of State
Congress having referred to me the Petition of Jacob Isaccks praying a reward for a secret he possesses of converting Salt-water into fresh, I procured a Cask of sea-water to be taken up without the Capes of Delaware at flood-tide, and brought to Philadelphia, and asked the favour of Mr. Rittenhouse, President of the American Philosophical Society, of Dr. Caspar Wistar, Professor of Chemistry and the Institutions of Medecine in the College of Philadelphia, and Dr. James Hutchinson, Professor of Chemistry and Materia Medica in the University of Pennsylvania, to assist at the experiments which were to be made on it for determining the merit of Mr. Isaacks secret. They were so kind as to attend accordingly. The result of the experiments was as follows.
On the 14th. of March from 24 pints of Sea-water, with Mr. Isaack’s mixture, 22 pints of potable distilled water were produced in four hours, with the consumption of 20. pounds of seasoned pine, a little wetted by lying out in a rain. This distillation was performed in one of the pots of a small Cabouse, with a tin cap luted on, and a strait tin tube instead of a worm, two feet of which passed obliquely through a Barrel of water.
On the 21st. of March from 32 pints of Sea-water with Mr. Isaack’s mixture, 31 pints of potable distilled water were produced in 7 hours 24 minutes, with 51 pounds of hiccory which had been cut about six months. This was done in a furnace at the College, illy calculated to economise heat, and a five Gallon still and worm of the common form. A drop of the solution of silver in the nitrous acid was dropped into a glass of this water and produced a very slight milkiness, as it did in water distilled at the same time from Sea-water without any mixture1 in a small retort, and also in the common pump water of Philadelphia: and in the last most of the three.
On the 22d. of March, from 32 pints of Sea-water without any mixture 31 pints of potable distilled water were produced in 7 hours 35 minutes, with 41 pounds of wood. This was done in the same furnace and Still, and under the same circumstances exactly as on the 21st. The saving of wood proceeded probably, not from Mr. Isaack’s mixture rendering the separation of the water from it’s salt more difficult, but from a more skilful management of the fire on the 22d. In the course of this operation the fire being once a little too much pushed, the violence of the ebullition threw about half a pint of salt-water over into the tube.
On the 24th. from 16 pints of Sea-water with Mr. Isaacks mixture 15 pints of potable distilled water was produced in 2 hours 55 minutes with 11 pounds of wood, 3 pounds of which were of dry hiccory and 8 pounds of seasoned and dry pine. This was done in a common iron pot of 3½ Gallons cased in brick and mortar, the flue passing spirally round the pot once, the same cap and pipe as on the 14th.
On the 25th. from 16 pints of Sea-water without any mixture 15 pints of potable distilled water were produced in 2 hours 56 minutes with 10½ pounds of wood, vizt. 3 pounds of dry hiccory and 7½ pounds of seasoned and dry pine in the same furnace and pot and all other circumstances the same as on the 24th.
It will be perceived that the experiment of the 22d. without a mixture was an exact repetition of that of the 21st. with the mixture, and that of the 25th. without a mixture an exact repetition of that of the 24th. with a mixture, and that the result is that2 in both ways equal quantities of distilled water were produced from equal quantities of sea-water, in about the same time, and that less fuel was used in the simple distillation without any mixture: consequently that as far as these experiments justify a conclusion, Mr. Isaack’s mixture does not facilitate the separation of sea-water from it’s salt.
Given under my hand at Philadelphia this 26th. day of March 1791.
PrC (DLC); in clerk’s hand except for signature and interlineations in TJ’s hand, as noted below. Tr (MHi); incomplete. Not recorded in SJL or SJPL.
This affidavit was probably executed at the request of Isaacks. If so, the original must have been enclosed in TJ’s letter to Isaacks of this date, recorded in SJL under 26 Mch. 1791 but not found. It is to be noted that TJ kept no record of this affidavit in his departmental files, evidently because the experiments were made not because Isaacks requested them but in order to enable TJ to report to the House of Representatives on the petition referred to him (see TJ’s report, 21 Nov. 1791).
1. Preceding three words interlined in TJ’s hand.
2. Preceding two words interlined in TJ’s hand.