at the will of the worker to the various light, magnifying, and chemical and electric processes which it seemed to be the function of the machine to keep in action.
I did not feel sure at first whether the substances in the vessels were being simply examined, or whether they were being treated with a view to effect some change in them. But I soon saw that the latter was the more likely purpose. For I perceived on further observation that they were subjected to a very severe and exact scrutiny before they were placed in the vessels. At one end of the row of machines was a very long table along which, near the middle, a trough ran from end to end. A man stood at the table who seemed to be examining something in the trough with a microscope, or at least with some sort of magnifying apparatus. Then he laid aside the magnifying apparatus, and poured from a little bottle either some fluid or powder, I could not tell which, on the objects which he was examining; then he would apply the magnifier again, and so on. Last of all, from this trough he would take up something or other with a little shovel or trowel, and place it in certain tiny waggons or boxes on wheels which communicated, apparently by automatic means such as I have before described, with the different machines, emptying their contents into the