his singular delusion may have been partly due to errors of observation, the instruments and methods of former times having been notably crude and unreliable. This fact, taken in connection with the wild theories upon which the natural sciences of the middle ages were based, is a sufficient explanation of some of the extraordinary statements made by Kircher, Schott, Digby, and others.

By palingenesy these writers meant a certain chemical process by means of which a plant or an animal might be revived from its ashes. In other words a sort of material resurrection. Most of the accounts given by the old authors go no further than to assert that by proper methods the ashes of plants, when treated with water, produce small forests of ferns and pines. Thus, an English chemist, named Coxe, asserts that having extracted and dissolved the essential salts of fern, and then filtered the liquor, he observed, after leaving it at rest for five or six weeks, a vegetation of small ferns adhering to the bottom of the vessel. The same chemist, having mixed northern potash with an equal quantity of sal ammoniac, saw, some time after, a small forest of pines and other trees, with which he was not acquainted, rising from the bottom of the vessel.

And Kircher tells us in his "Ars Magnetica" that he had a long-necked phial, hermetically sealed, containing the ashes of a plant which he could revive at pleasure by means of heat; and that he showed this wonderful phenomenon to Christina, Queen of Sweden, who was highly delighted with it. Unfortunately he left this valuable curiosity one cold day in his window and it was entirely destroyed by the frost. Father Schott also asserts that he saw this chemical wonder which, according to his account, was a rose revived from its ashes. And he adds that a certain prince having requested Kircher to make him one of the same kind, he chose rather to give up his own than to repeat the operation.

Even the celebrated Boyle, though not very favorable to palingenesy, relates that having dissolved in water some verdigris, which, as is well known, is produced by combining copper with the acid of vinegar, and having caused this water to congeal, by means of artificial cold, he observed, at the surface of the ice, small figures which had an exact resemblance to vines.

In this connection it is well to bear in mind that in Boyle's time almost all vinegar was really what its name implies—sour wine (vin aigre)—and verdigris or copper acetate was generally prepared by exposing copper plates to the action of refuse grapes which had been allowed to ferment and become sour. Therefore to him it might not have seemed so very improbable that the green crystals which appeared on the surface of the ice were, in reality, minute resuscitated grape-vines.

The explanation of these facts given by Father Kircher is worthy of the science of the times. He tells us that the seminal virtue of each mixture is contained in its salts and these salts, unalterable by their nature, when put in motion by heat, rise in the vessel through the liquor in which they are diffused. Being then at liberty to arrange themselves at pleasure, they place themselves in that order in which they would be placed by the effect of vegetation, or the same as they occupied before the body to which they belonged had been decomposed by the fire; in short, they form a plant, or the phantom of a plant, which has a perfect resemblance to the one destroyed.

That the operators have here mistaken for true vegetable growth the fern-like crystals of the salts which exist in the ashes of all plants is very obvious. Their knowledge of plant structure was exceedingly limited and their microscopes were so imperfect that imagination had free scope. As seen under our modern microscopes, there are few prettier sights than the crystallization of such salts as sal ammoniac, potassic nitrate, barium chloride, etc. The crystals are actually seen to grow and it would not require a very great stretch of the imagination to convince one that the growth is due to a living organism. Indeed, this view has actually been taken in an article which recently appeared in a prominent magazine. The writer of that article sees no difference between the mere aggregation of inorganic particles brought together by voltaic action and the building up of vital structures under the influence of organic forces. This is simply materialism run mad.

Perhaps the finest illustration of such crystallization is to be found in the deposition of silver from a solution of the nitrate as seen under the microscope. A drop of the solution is placed on a glass slide and while the observer watches it through a low power, a piece of copper wire or, preferably, a minute quantity of the amalgam of tin and mercury, such as is used for "silvering" cheap looking glasses, is brought into contact with it. Chemical decomposition at once sets in and then the silver thus deposited forms one element of a very minute voltaic couple and fresh crystals of silver are deposited upon the silver already thrown down. When the illumination of this object under the microscope is properly managed, the appearance, which resembles that shown in Fig. 18, is exceedingly brilliant, and beautiful beyond description.

That imagination played strange pranks in the observations of the older microscopists is shown by some of the engravings found in their books. I have now before me a thick, dumpy quarto in which the so-called seminal animalcules are depicted as little men and women, and I have no doubt that, to the eye of this early observer, they had that appearance. But the microscopists of to-day know better.

Sir Kenelm Digby, whose name is associated with the Sympathetic Powder, tells us that he took the ashes of burnt crabs, dissolved them in water and, after subjecting the whole to a tedious process, small crabs were produced in the liquor. These were nourished with blood from the ox, and, after a time, left to themselves in some stream where they throve and grew large.

Now, although Evelyn, in his diary, declares that "Sir Kenelm was an errant mountebank," it is quite possible that he was honest in his account of his experiments and that he was merely led astray by the imperfection of his instruments of observation. It is more than likely that the creatures which Digby saw were entomostraca introduced in the form of ova which, unless a good microscope be used, are quite invisible. These would develop rapidly and might easily be mistaken for some species of crab, though, when examined with proper instruments, all resemblance vanishes. When let loose in a running stream it would evidently be impossible to trace their identity and follow their growth.

But while some of these stories may have originated in errors of observation this will hardly explain some of the statements made by those who have advocated this strange doctrine. Father Schott, in his "Physica Curiosa," gives an account of the resurrection of a sparrow and actually gives an engraving in which the bird is shown in a bottle revived!

Although the subject, of itself, is not worthy of a moment's consideration, it deserves attention as an illustration of the extraordinary vagaries into which the human mind is liable to fall.