MICROSCOPE. 



661 



imagined it possible to distinguish myriads of living 

 creatures in a single drop of water ? or that the 

 purple tide of life, and even the globules of the 

 blood, should be seen distinctly rolling through 

 veins and arteries smaller than the finest hair ? 

 That millions of millions of animalcules should be 

 discovered in the semen masculinum of all crea- 

 tures? That not only the exterior form, but even 

 the internal structure of the bowels, and the mo- 

 tion of the fluids in a gnat or louse should be 

 rendered objects of sight? Or that numberless 

 species of creatures should be made visible, though 

 so minute, that a million of them are less than a 

 grain of sand? These," he continues, "are noble 

 discoveries, whereon a new philosophy has been 

 raised, that enlarges the capacity of the human 

 soul, and furnishes a more just and sublime idea 

 than mankind had before of the grandeur and 

 magnificence of nature, and the infinite power, 

 wisdom, and goodness of nature's Almighty parent." 



The observations of Leeuwenhoeck were di- 

 rected to every conceivable object in the animal 

 and vegetable kingdoms, and so indefatigable was 

 he in his researches, that had he possessed instru- 

 ments of sufficient power and delicacy, succeeding 

 inquirers into the mysteries of nature, would pro- 

 bably have found themselves anticipated at every 

 step. He left scarcely any thing unexamined that 

 his microscopes would reach ; and though improved 

 constructions have unveiled wonders never revealed 

 to him, they have rarely discovered errors in his 

 observations, so far as they extend. The researches 

 of his predecessor Dr Hooke, for the reason before 

 given, were not so happily conducted ; he greatly 

 marred the usefulness of his discoveries by the as- 

 sumption of unwarrantable hypotheses, and parti- 

 cularly by the pertinacity with which he clung to 

 the doctrine of equivocal generation, though facts 

 were daily disproving the monstrous supposition. 

 In despite of these blemishes, however, he did good 

 service to microscopic discovery ; and some allow- 

 ance ought surely to be made for the aberrations 

 of a mind naturally inclined to speculation, when 

 wonders new and strange were continually rising 

 up before it to excite its energies, and, in not a few 

 cases, to confound them. 



The recent achievements of the microscope may 

 be described as accurate examinations in detail of 

 those objects which had been imperfectly observed 

 by the early micrographers, owing to the compar- 

 ative inefficiency of their instruments; new disco- 

 veries in the animalcular kingdom; and experi- 

 mental inquiries concerning objects progressively 

 suggested by constantly increasing information in 

 the various departments of natural science. There 

 are two classes of objects to which great attention 

 has recently been directed, and concerning which 

 many wonderful and interesting discoveries have 

 been made : these are, infusorial animalcules and 

 the microscopic tests. The information obtained 

 respecting the latter class, may by some be esteemed 

 more curious than useful ; we believe, however, 

 that few persons, on due reflection, will consider it 

 beneath the dignity of science, to investigate the 

 minutest atom, since it could be produced only by 

 the same creative energy that evoked the universe 

 into being. The elaborate examinations that have 

 been made regarding infusorial animalcules, it will 

 be admitted on all hands, have brought vast acces- 

 sions to our knowledge of animated nature. Of 

 these atomic germs of vitality, little had been pre- 

 viously discovered beyond the fact of their exis- 



tence ; and indeed many species, on account of their 

 extreme minuteness, and the vast amplifying power 

 requisite for their development, had not till very 

 recently been observed at all. It is not however 

 to their mere existence, that the microscopist 

 now calls attention, but to all the details of their 

 external form and internal structure, to their 

 habits, modes of action, natural instincts, and to 

 all the economy of their being. The mind is over- 

 whelmed and confounded, whilst we read (as Mr 

 Pritchard, in his Natural History of Animalcules, 

 has enabled us to do) of the organization and vital 

 properties of a living atom, so inconceivably 

 minute, that five hundred millions of them in a 

 mass would present little more than a sensible 

 point to the unassisted eye. Such an announce- 

 ment will be met by much scepticism, and scep- 

 ticism in this instance is indeed pardonable ; for 

 with the object before him, the observer can 

 scarcely yield his belief, whilst mathematical truth 

 and actual observation are attesting the fact. 



Test Objects Many of the improvements re- 

 cently introduced into microscopic elements, are 

 the results of elaborate inquiries, regarding that 

 delicate class of objects named the tests; for the 

 inefficiency of the ordinary constructions is never 

 more apparent than when brought to bear upon 

 them. Dr Goring has the merit of being the first 

 observer of these objects, or at least the first to 

 examine into all their details. His attention ap- 

 pears to have been drawn to them by the remarks 

 of Leeuwenhoeck, on an observation of the wing 

 of a silk-worm moth : " If we examine the wings 

 of this creature by the microscope, we shall find 

 them covered with an incredible number of feathers, 

 of such various forms, that if an hundred or more 

 of them were to be seen lying together, each would 

 appear of a different shape." The micrographer 

 adds some allusions to "the ribs or streaks in each 

 feather," which the limner he employed had diffi- 

 culty in discerning under the power of his micro- 

 scope. It appeared to Dr Goring, from these re- 

 marks, that there must be something about these 

 feathers (or rather, scales') that fitted them for ex- 

 cellent tests of the defining and penetrating power 

 of microscopes. He accordingly commenced an 

 examination into all the varieties of plumage on 

 the wings of papilio ; and succeeded, at one and 

 the same time, in developing their wonderful struc- 

 ture, and in determining some of the most impor- 

 tant desiderata in the elements of the micro- 

 scope. The scales of butterflies and moths are the 

 principal tests of penetrating power ; they form 

 that impalpable dust which clings to the finger 

 when we touch the wings of those insects. A 

 variety of objects testing the defining power have 

 also been brought under examination ; of these 

 the hair of the dermestis, bat, mouse, &c. are very 

 remarkable. We defer more extended mention of 

 these objects, till we come to describe the illustra- 

 tive engravings. 



Infusorial Animalcules The term infusorial is 

 applied to the various species of animalcules, dis- 

 coverable in vegetable and animal infusions. They 

 exist naturally in all stagnant waters, wherein ve- 

 getable matter is decomposing ; and they can be 

 produced artificially by making an infusion of vege- 

 table substances, and suffering it to stand till it 

 has fermented, and become in some degree putrid. 

 The most rational and philosophical way of ac- 

 counting for the presence of animalcules in in- 

 fusions, is to adopt the hypothesis, that the atmos- 



