360 
POPULAR SCIENCE REVIEW. 
rubbing a piece of amber, which, 2,000 years before, had 
attracted the attention of those philosophers among the ancients 
who did not despise the small things in nature.” 
The discoveries and experiments of Stephen Gray awakened 
fresh enquiry into the long-neglected phenomenon of the amber 
tear; but, although simultaneously we find Watson in England, 
Du Lac in Switzerland, and Franklin in America, transmitting 
the “ electric fire ” to great distances, it does not seem to have 
occurred even to the reflective mind of the latter that an intel- 
ligent and obedient thunderbolt was forged and already in their 
hands. The first published appropriation to the purposes of 
telegraphy of Gray’s experimental proof that electricity can 
travel along wires, is to be found in the “ Scots’ Magazine ” for 
1753. One “ C. M.,” writing from Eenfrew, there details a 
scheme for the construction of a land telegraph ; but, although 
this was sufficiently startling to turn attention to the realisation 
of the idea it put forth, all efforts to effect a successful con- 
summation were unavailing, owing to the insurmountable diffi- 
culty of preventing the frictional electricity they had no choice 
but to employ, from escaping out of the wires they used. But 
Nature, with a kindly accordance to our wishes which we some- 
times see in her, had provided a less refractory and more docile 
kind of electricity, which was all around us, lurking like a shy 
fairy among the atoms of all metallic and non-metallic bodies, 
whatever their guise, in the great kingdoms of solid and fluid 
matter. And, with a praiseworthy liberality, she seems to have 
decreed that some familiar products of industry should yield us 
the best supply. In the minerals zinc, iron, copper, and 
carbon, water and the common acids, we have a source of 
electricity which far-seeing Stephen Lrray could scarcely have 
dreamt of, and which we might -still have been ignorantly 
stumbling about in the dark, but for the fact that there 
occurred to a man of philosophic spirit one of those chance 
discoveries which seem to be inseparably connected with the 
progress of electrical science. As early as 1767, we are told, 
Sulzer had discovered that pungent sandwich of the tongue and 
two dissimilar metals, as zinc and copper, which now “ every 
school-boy knows but in this case Nature had been somewhat 
careless in the casting of her pearl, and twenty-three years 
passed away ere she astonished the eyes and fired the enquiring 
mind of Galvani with one of her coy revelations. Madame 
Galvani, having caught a slight cold, was recommended to try 
frog-broth ; and while, like a good housewife, she was inspect- 
ing the skinned victims, which, by the way, occupied the some- 
what unattractive position of a place on an operating table in 
the professor’s laboratory, she observed startling convulsions in 
the dead frogs’ limbs (every time an assistant, who was present, 
