It occurred to the author, while examining the fossils of various strata, that possibly the animal matter of the animals originally included in the rock might have played some part in its consolidation, and thus, after their destruction as living animals, they might have continued to serve a useful purpose.

After many unsuccessful experiments, made with common lime, and raw animal or vegetable matter, she had recourse to sulphate of lime, and found that plaster of Paris, when mixed with water, and with not more than part of the weight of the whole mass of mixed animal and vegetable matter, it did not set instantly, but continued for some hours quite plastic, developed, in setting, more heat than usual, and finally acquired a remarkable degree of hardness, and the power of resisting both water and fire to a very great degree. A specimen, was exhibited, made in this way.