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Show 9o PARTICULAR CONSIDER.A TIC.NS ON THE was ad.d~d in the era of the new red sandstone, wl.en the earth had become suited for such a creature, so may these creatures have been added when media, suitable for their existence arose, and that such phenomena may take place any day, the only cause for their taking place seldom being the rarity of the rise of new physical conditions on a globe which seems to have already undergone the principal part of irs destined mutations? Between such isolated facts and the greater changes which attended various geological eras, it is not easy to see any difference, besides simply that of the scale on which the respective phenomena took place, as the throwing off of one copy from an engraved plate is exactly the same process as that by which a thousand are thrown off. Nothing is more easy to conceive than that to Ct·eative ?rovidence the numbers of such phenomena, the time when, and the circumstances under ·which they take place, 11\ are indifferent matters. The Eternal One has arranged for everything beforehand, and trusted all to the operation of the laws of his appointment, himself being ever present in all things. We can even conceive that man, In his 1nany doings upon the surface of the earth, may occasionally, without his being aware of it, or otherwise, act as an instrument in preparing the association of conditions under which the creative laws work; and perhaps some instances of his having acted as such an instrument have actually occurred in our own time. I allude, of course, to the experiments conducted a few years ago, by Mr. Crosse, which seemed to result in the production of the heretofore unknO\vn species of insect in considerable numbers. Various causes have prevented these experiments and their results from receiving candid treatment, but they may perhap~ be yet found to have opened up a new and most interesting chapter of nature's mysteries. Mr. Crm;se was pursuing some experiments in crystallization, causing a powerful voltaic battery to operate upon a saturated solutwn of silicate of potash, 'l'.rhcn the insects unexpectedly made their appearance. IIe afterwards tried nitrate of copper, which is a deadly poison, and from that fluid also did live insects emerge Discouraged by the reception of his experiments.. Mr Crosse soon discontinued them; but they -yvere some years after pursued by Mr. Week~s, of Sandwich, .with p:ecisclv the same results. This gentleman, besides try1ng ORIGIN OF THE A.NIMATEJl TRIBES • 97 ttle fint of the above substances, employed ferro-cyanet of potash, on acc?u~t of its containing a ~:nger p1·oportion of carbon, the pnnc1pal element of organic bodies· and from this substance the insects wer~ produced in 'increased numbers. A few weeks sufficed for this experiment, with the powerful battery of Mr. Crosse, but the first attempts of Mr. Weekes required about eleven months, a ground of presumption in itself that the electricity was chiefly concerned in the phenomenon. The changes undergone by the fluid operated upon, were in both cases remarkable, and nearly alike. In ~vrr. Weekes' apparatus, the silicate of potash became first turbid, then of a milky appearance; round the negative wire of the battery, dipped into the fluid, there gathered a quantity of gelatinous matter, a part of the process of consjderable importance, considering that gelatin is one of the proximate principles, or first compounds of which animal bodies are fol'med. From this matter, Mr. Weekes observed one of the insects in the VPry act of emerging, immediately after which, it ascended to the surface of the fluid and sought concealment in an obscure corner of the apparatus. The insects p.roduced by both experimentalists seem to have been the same, a species of acarus, minute and semi-transparent, and furnished with long bristles, which can only be seen by the Aid of the microscope. It is worthy of remark, that some of these insects, soon after their existence had commenced, were found to be likely to extend their species. They were sometimes observed to go back to the fluid to feed, and occasionally they devoured each other.* The reception of novelties in science must ever be regulated very much by the amount of kindred or relative phenomena which the public mind already possesses and acknowledges, to which the new can be assimilated. A novelty, howen~r true, if there be no received truths with which it can be shown in harmonious relation, has little chance of a favorable hearing. In fact, as has often been observed, there is a measure of incredulity from our ignorance as well as from our knowledge, and if the most distinguished philosopher three hundred years ago, h~d ventured to develop any striking new fact which only could harmonize with the as yet unknown Copernican solar system, we cannot doubt th2 t it would have been univer~ sally scoffed at in the scientific world, such as it then • See a pamphlet circulated by Mr. Weekes, in 1842. |