The object of the following paper is to lay before the Royal Society the results of a repetition of several of Dr Samuel Brown's processes for the conversion of carbon into silicon. The greater number of these processes were published in the Society's Transactions for 1840–41; and certain additional ones have since appeared in a separate form. The latter were much simpler, and more readily performed, than those made public at an earlier period; and to one of these we first directed our attention.