a collection of ancient indian science & technology battery The Agastya Samhita, an ancient Indian text, gives directions on how to make a battery: "Place a well-cleaned copper plate in an earthenware vessel. Cover it first by copper sulfate and then moist sawdust. After that put a mercury-amalgamated-zinc sheet on top of an energy known by the twin name of Mitra-Varuna. Water will be split by this current into Pranavayu and Udanavayu. A chain of one hundred jars is said to give a very active and effective force." By the way, Mitra-Varuna is now called cathode-anode, and Pranavayu and Udanavayu are to us oxygen and hydrogen, respectively.