664 



MICROSCOPE. 



to state it is now an ascertained fact, that a large 

 proportion of the siliceous formations of this ter- 

 restial globe, are actually composed of the testa- 

 ceous coverings of Infusoria. 



In completion of our design in the present article, 

 we now proceed to describe and remark upon the 

 accompanying engravings illustrative of micro- 

 scopic discovery. We would just observe, in this 

 place, that we have purposely taken an extended 

 range in the selection of objects, to show the in- 

 quirer into nature's mysteries, that an examination 

 of details, throughout the whole compass of animate 

 and inanimate matter, presents much to interest 

 and instruct ; we have likewise employed extreme 

 powers for their developement, it being our wish 

 at one and the same time to exhibit what the 

 microscope can do in all its efficiency, and what the 

 observer can do with an instrument of very limited 

 powers. 



A very interesting and remarkable class of micro- 

 scopic objects is presented in the hairs of different 

 animals, which exhibit a most wonderful variety 

 and delicacy of formation. Hooke, Leuwenboeck, 

 and others, endeavoured to discover their peculiari- 

 ties, and to a certain extent they succeeded ; but 

 the instruments used by these early micrographers, 

 wanted the defining power necessary for the per- 

 fect development. We have introduced seven 

 varieties into our illustrative engravings, and from 

 these we believe a good general idea may be formed 

 concerning this description of objects. 



Plate 90, fig. 1 . The hair of the Dermestes This 

 insect belongs to the order Coleoptera, (see Entomo- 

 logy), and is remarkable for the beautifully formed 

 hair which covers it in the larva state. There is a 

 variety in the structure ; some of the hairs resem- 

 bling an oat bread, and others exhibiting the charac- 

 ter shown in our specimen. A more delicate and 

 beautiful object than the spear-shaped hair can 

 scarcely be submitted to the microscope. The 

 lowest power by which it can be seen, is 100 linear, 

 but to develope its details satisfactorily, a power of 

 200 linear is requisite, which is the one we have 

 used. This object is considered an excellent test 

 of the defining power of a good microscope. 



Fig. 2. The hair of a Mouse The characteris- 

 tics of this object, when viewed by transmitted 

 light, are dark transverse stripes, some of which are 

 broken, whilst others extend quite across the hair. 

 On closer observation these appearances are dis- 

 covered to arise from a kind of spiral spring 

 occupying the tube of the hair, and a number of 

 imperforations on the surface. 



Fig. 3. The hair of a Bat From the resem- 

 blance between the mouse and bat, it will excite a 

 little surprise to observe the very decisive difference 

 of structure in the hair of these two animals. That 

 of the latter sometimes presents the appearance of 

 a screw, or of a number of small conical cups in- 

 serted into each other ; other specimens seem to be 

 formed of two distinct hairs twisted together; and 

 some exhibit, in connection with these peculiarities, 

 striped markings resembling those on the hair of 

 the mouse. 



Fig. 4. The hair of a Bee. This is a very 

 beautiful object, but requires a good defining power 

 to show the structure satisfactorily. The hair it- 

 self resembles a jointed bamboo cane; and from each 

 joint small delicate spikes shoot out. The hair 

 terminates in a number of these spikes, one of 

 which is uniformly longer than the rest. 



Fig. 5. The hair of a Dormouse. This object 



very much resembles the hair of a mouse. The 

 points of difference seem to consist in the regularity 

 of the stripes on that of the dormouse, and its 

 greater delicacy. 



Fig. 6. The hair of a Mole This is a very 



singular structure. The interior exhibits the re- 

 markable spiral observed in the hair of the mouse 

 and dormouse, and the exterior presents a forma- 

 tion somewhat similar to that of the bat's hair. 



Fig. 7. The hair of a Caterpillar We notice a 



strong resemblance between this object and the hair 

 of a bee. The tube of the hair is not jointed, how- 

 ever, in the caterpillar ; and the lateral spines curve 

 the contrary way. This and the preceding figures 

 are all shown under a doublet linear power of 200. 



Fig. 8. A filament of Feather Down This ex- 

 hibits an exceedingly minute formation that was 

 observed under a doublet linear power of 300. The 

 exquisite finish of the joints was very remarkable. 



Fig. 9. The Down of a Flower, The down of 

 flowers may in some cases be termed a parasitical 

 plant that is nourished by the florescence to which 

 it clings till it is able to provide for itself; in other 

 cases.it is an appendage to the seeds of the plants with 

 which it is connected, and furnishes them with means 

 of conveyance to places far distant from the parent 

 flower. To this wonderful provision of nature for 

 the propagation of vegetable life, we are to attri- 

 bute the verdure and floral loveliness of those wild 

 sequestered spots, where the cultivating hand of 

 man has never been employed, and where the 

 human foot has rarely trod. The summer gale 

 wafts these vegetable fibres over the earth ; they 

 alight in their course, cling, take root, and ulti- 

 mately spring up an hundred fold. The formation 

 of the down of flowers, presents a wonderful 

 variety. It sometimes appears plain and smooth, 

 at others, rough and thorny, with little hooks or 

 barbs, by which the fibre clings to the spot where 

 it has fallen, and is enabled to strike root into the 

 earth. There is no class of microscopic objects 

 more interesting and instructive than this; and the 

 details of the various species may, in most cases, be 

 developed satisfactorily by an instrument of very 

 moderate power. The object shown in the engrav- 

 ing is' a fibre of thistle down, as it appears under 

 an amplifying linear power of eighty.* 



When speaking of the test-objects, we noticed 

 a remark by Leeuwenhoeck, regarding the scales 

 of butterflies, "that if an hundred, or more, of 

 them were to be seen lying together, each would 

 appear of a different shape." Now, though this 

 observation is strictly true, inasmuch as there is 

 the same variety exhibited in the formation of 

 these atoms as in that of the human countenance, 

 still this is not the grand point of admiration ; the 

 most wonderful fact connected with them is, that 

 amidst all the variety of individuals, we no more 

 mistake the different species of these scales, than 

 we do the various species of the human race, in 

 consequence of the great variety of features observ- 

 able in each. Let Materialists, and O \venites, and 

 all who would dethrone Deity, and deify nature, 

 inform us regarding those subtile laws which deter- 

 mine with such wonderful exactness the formation 

 of these atoms. If brute matter possesses an in- 

 herent plastic energy to mould existences like 

 these, let us no longer exalt mind and reason, but 

 refer them to a subordinate place. If, however, 



# We have expressed the magnifying power in linear mea- 

 sure, with refereni > to this and the preceding objects ; the 

 reason for doing > will be ohv'mus. 



