Edward Daniel Clarke

“ It may therefore be considered as a discovery of some importance, that we possess, in this country, a species of limestone which, when used for purposes of extracting lime, and in the preparation of mortar, is capable of communicating to the cement all the properties of the pulvis Puteolanus. ”

“ The supernatant acid used in this experiment being decanted, and neutralized by the addition of an alkali, yielded no precipitate of iron to the tincture of galls; but the prussiate of potass threw down a blue precipitate upon which however no reliance can be placed; as it is well known that the prussiate of potass is not a satisfactory test of the presence of iron when this metal exists in an inconsiderable portion. ”

“ The remainder being reduced to powder in a porcelain mortar and exposed to diluted muriatic acid until all effervescence ceased, there remained an insoluble residue of the original dark colour of the limestone, which when carefully washed and dried, weighed 10 grains ”