E. H. Lewis in August 2006 notes that Benjamin Franklin may have been one of the earliest 'Cold Fusion' researchers all the way back in the 1700s.

For example, several hundred years ago, Benjamin Franklin as a part of his research which helped to establish the paradigm of electrical and heat fluids for physics, studied what he called, ironically, “cold fusion”
xviii phenomena. By this term he meant the anomalous effect of lightning strikes on metallic objects. These metallic objects, such as coins in a pocket or a sword in a scabbard, seemed to have melted, but he thought it was odd that there was no trace of burning or scorching of the
material around the objects, as would be expected if the metals became hot enough to melt. He called this phenomenon “cold fusion” because the objects fused though they were cold. The modern cold fusion phenomenon of atoms fusing or changing behavior is really a part of this same effect of atoms behaving anomalously under stressful conditions such as the presence of BL or electricity.

And further on in the same document ed notes

K. Shoulders published Figs. 6 and 7 as an example of this behavior of material(19). He wrote that two plasmoids passed all the way through a sample of aluminum oxide, and then hit a 6-micrometer-thick sample of aluminum that was coated with wax and passed through that also. The two plasmoids left the two small holes in the aluminum sample as shown in Fig. 6. Fig. 7 is a magnification of one of the entry pits into the aluminum target. He reported that the plasmoid passed all the way through the aluminum sample target also. The white deposit around the holes is aluminum oxide from the aluminum oxide sample. He reports that though the aluminum oxide atoms traveled from the aluminum oxide sample to spread themselves on the aluminum target sample, they were not hot. He wrote that the atoms of aluminum oxide had spread themselves out on the target to a thickness of a 1-atom layer, but a coating of wax on the sample was not melted at all. He wrote: “Aluminum oxide has a melting point of 2,050 degrees centigrade, and yet, it has not raised the temperature of the thin substrate material in any perceptible way. Even a thin coating of low temperature wax on the surface, to serve as a temperature indicator, remains undisturbed.(19)