Benjamin Franklin Papers

From Benjamin Franklin to Cadwallader Colden, 28 June 1750

To Cadwallader Colden

ALS: New-York Historical Society

Philada. June 28. 1750


I wrote a Line to you last Post, and sent you some Electrical Observations and Experiments. You formerly had those Papers of mine out of which something has been taken by Mr. Watson, and inserted in the Transactions:9 If you have forgot the Contents of those Papers, I am afraid some Things in that I last sent you will be hardly understood, as they depend on what went before. I send you herewith my Essay towards a new Hypothesis of the Cause and Effects of Lightning, &c. of which you may remember some Hints in my first Electrical Minutes.1 I sent this Essay above a 12 month since to Dr. Mitchel in London, and have since heard nothing of it, which makes me doubt of its getting to hand. In some late Experiments, I have not only frequently fired unwarm’d Spirits, by the Electrical Stroke, but have even melted small Quantities of Copper, Silver and Gold, and not only melted but vitrified them, so as to incorporate them with common Glass; and this without any sensible Heat; which strengthens my Supposition that the Melting of Metals by Lightning may be a cold Fusion.2 Of these Experiments I shall shortly write a particular Account. I wrote to Mr. Collinson, on Reading in the Transactions the Accounts from Italy and Germany, of giving Purges, transferring Odours, &c. with the Electrical Effluvia, that I was persuaded they were not true. He since informs me,3 that Abbé Nolet of Paris, who had try’d the Experiments without Success, was lately at the Pains to make a Journey to Turin, Bologna and Venice, to enquire into the Facts, and see the Experiments repeated, imagining they had there some Knacks of Operating that he was unacquainted with; but to his great Disappointment found little or no Satisfaction; the Gentlemen there having been too premature in Publishing their Imaginations and Expectations for real Experiments. Please to return me the Papers when you have perus’d them.

My good old Friend Mr. Logan, being about three Months since struck with a Palsey, continues Speechless, tho’ he knows People, and seems in some Degree to retain his Memory and Understanding. I fear he will not recover.4 Mr. Kalm is gone towards Canada again, and Mr. Evans is about to take a Journey to Lake Erie, which he intends next Week.5 Mr. Bertram continues well and hearty. I thank you for what you write concerning celestial Observations. We are going on with our Building for the Academy, and propose to have an Observatory on the Top; and as we shall have a mathematical Professor, I doubt not but we shall soon be able to send you some Observations accurately made. I am, with great Esteem and Respect, Sir, Your most obliged Humble Servant

B Franklin

P.S. If you think it would be agreable to Mr. Alexander,6 or any other Friend in N York, to peruse these Electrical Papers, you may return them to me thro’ his Hands.

Cr. Colden Esqr

[Note numbering follows the Franklin Papers source.]

9See above, p. 126.

1See above, p. 365.

3April 25, 1750, above, p. 476.

4James Logan died Oct. 31, 1751.

5Peter Kalm traveled through the Iroquois country to Lake Ontario in the summer of 1750, visiting Forts Oswego and Niagara, and viewing Niagara Falls, which he described in a famous letter to BF, Sept. 2, printed in Pa. Gaz., Sept. 20. Kalm, Travels, II, 694–6. Kalm’s letter was also printed as an appendix to John Bartram’s Observations … In his Travels from Pensilvania To Onondago, Oswego and the Lake Ontario, In Canada (London, 1751).

Lewis Evans changed his plans and did not leave Philadelphia. On the Proprietors’ proposal to have Evans and John Bartram make a journey to the western parts ostensibly for scientific purposes but in reality to check the boundaries of the province, see Lawrence H. Gipson, Lewis Evans (Phila., 1939), pp. 33–8.

6James Alexander, member of the New York Council, a man of mathematical interests. See above, p. 32 n, and 11, 407.

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