Few, if any, analyses of British aragonites have been published; that which I now submit was executed upon a specimen forwarded to me by Professor Heddle, who has supplied me with the following notes of its occurrence.

It was obtained by him at Sobul Hill, in Unst, Shetland.

The west side of the hill of Sobul is pitted for the extent of nearly a mile with quarry holes, opened in a search for chromite.