And his busy fingers were continuously feeling the great circular bronze matrix, and a moment afterwards its sulphur-cast.

The petrified bodies should, if possible, be kept united with portions of the rock or matrix in which they are found; and where they are numerous, in sand, clay, or any moist or friable matrix, it is in general better to retain a large portion of the whole mass, to be examined afterwards, than to attempt their separation at the time of collecting. 8.

Examined chemically, it proves to be composed almost wholly of carbonate of lime; and if you make a section of it, in the same way as that of the piece of chalk was made, and view it with the microscope, it presents innumerable Globigerinoe embedded in a granular matrix.

No son of Paian he, but a fatherless, full-grown birth from the incessant matrix of Modern Time, so motherly of monstrous litters of "Gorgon and Hydra and Chimaeras dire"; you will understand what I mean when you consider the quite recent date of, say, the introduction of anaesthetics or antiseptics, the discovery of the knee-jerk, bacteriology, or even of such a doctrine as the circulation of the blood.