Read it through once

'In 1828 Professor Bianchi demonstrated how the fearful reappearance of the plague at Modena was caused by excavations in ground where, _three hundred years previously_, the victims of the pestilence had been buried. Mr. Cooper, in explaining the causes of some epidemics, remarks that the opening of the plague burial-grounds at Eyam resulted in an immediate outbreak of disease.'--_North American Review, No. 3, Vol. 135._