110 



HARDWICKE'S SCIENCE-GOSSIP. 



likewise, almost universally, and had done so for 

 ages, however absurd it appears to us. For which 

 Reasons it has not been judged convenient to 

 reprint the Mlcrographia, but to give rather some 

 short and plain Descriptions of its Pictures without 

 meddling at all with its Opinions or Hypotheses" 



The following list of what were considered 

 microscopic objects two hundred years ago will 

 not be wholly devoid of interest to the modern 

 "microscopist." 



1. The point of a small needle x 200 diameters. ] 



2. A printed dot or Tittle do. do. 



3. Edge of a Razor x 20 diameters. 



4. Sparks struck from Flint and Steel. 



Iu the description of these, the following obser- 

 vation occurs. "The melting of the Particles of 

 Steel instantaneously upon the Collision is very 

 wonderful, and comes nearly to the effects of 

 Lightning. Indeed, there seems to be in Iron or 

 Steel a sulphureous combustible matter very easily 

 put in Action ; for either hammering, filing or 

 rubbing it with violence, will presently make it so 

 hot as to be able to burn one's Finger." 



5. Structure of several sorts of Hairs. 



" Our author says, that as far as he could find, 

 Human Hairs are all solid cylindrical bodies not 

 pervious like a Cane or Bulrush, but without any 

 Pith or Distinction of Rind, and imagines those 

 who assert them to be hollow, have not inspected 

 them with sufficient Care. Dr. Power on the contrary 

 makes no doubt that every one of our hairs is 

 hollow, which though our glasses cannot demonstrate 

 by reason of their Transparency, is palpably evinced 

 by that Disease in Poland, called the Plica, where 

 Blood drops from the ends of the Hairs of the Head, 

 and likewise issues out whenever they are cut, 

 which he thinks infallibly proves the tubulous 

 Cavity of them. But to this Dr. Hook [answers 

 that the Microscope gives no Encouragement to 

 believe our Hairs hollow, and that the very Essence 

 of the Distemper called the Plica Polonica may be 

 their growing hollow and of an unnatural Constitu- 

 tion. Malpighi asserts the Hairs of animals to be 

 tubular, that is composed of a Number of minute 

 Tubes or Pipes. Mr. Leeuwenhoek tells us that an 

 Human Hair cut transversely shews a Variety of 

 Vessels iu regular Figures." Disputes, in reference 

 to minute structure as revealed by the microscope, 

 occurred in those days, even as now, the difference 

 only consisting in the delicacy of the test : then, it 

 was the tubular or non-tubular structure of the 

 hair ; now, it is as to the existence or non-existence 

 of beading on the markings of a podura scale, or 

 whether the longitudinal lines of Frustulia saxonica 

 are capable of resolution, or whether what, are so 

 called are spurious and caused by diffraction. 



G. A pretty minute Shell found amongst sand. 



The figure represents a small Foramiuifer, pos- 

 sibly a Rotalia, of which the following descrip- 



tion is given. " This Shell appeared to the naked 

 Eye like a white Spot no bigger than the point of a 

 Pin, but when viewed by the Microscope it was 

 found in every Particular to resemble the flat spiral 

 Shell of a Water Snail, and had Wreathings (what 

 wenow know as chambers), all diminishing gradually 

 to wards the Middle or Centre, where there was a very 

 small round white Spot. 'Twas not easy to discover 

 whether it was hollow or not, but it rather seemed 

 to be filled with somewhat, and probably might Jbe 

 petrified, as larger Shells are often. 



"The Object under Observation informs us of an- 

 other genus where the Almighty Hand of the Maker 

 is amazingly exemplified in the Minuteness and Ele- 

 gance of the work. For we hereby find that the same 

 Power which contrived such minute Insects as Mites, 

 such minute Fishes as the Eels in Vinegar, and such 

 miuute Vegetables as Moss andMouldiness, haslike- 

 wise formed a Tribe of such minute shells as this be- 

 fore us, the Beauty of which could never have been 

 discovered without the Microscope's Assistance. It 

 was found accidentally amongst some white Sand 

 that was looked at with no other Design than to 

 try the goodness of some Glasses. But many 

 valuable Discoveries have been owing to lucky 

 Accident." 



7. " Some curious Forms of small Diamonds or 

 shining Sparks in Flints." 



We need scarcely observe that these small dia- 

 monds are only crystals of quartz of very frequent 

 occurrence in the cavities of flint. 



8. The forms of Gravel in urine. 



9. Snow-rlakes and Ice Crystals. 



10. A piece of Ketteriug-stone. 



The figure represents a fragment of oolitic lime- 

 stone. 



11. The configuration of Spunge. 



Dr. Hooke, in his description of the structure of 

 spunge, quotes a passage from Bellonius' 2nd book 

 de Aquatilibus, chapter II., which we reproduce- 

 " Spunges inthe Sea are extremely different from what 

 they are when dry, sticking to the Rocks, as many 

 Species of the Fungi do to Trees two or three Foot 

 sometimes under the Sea Water, tho' now and then 

 not above four inches, /fhose Hollows which we see 

 empty in Spunges, or in dry Spunges washed and 

 wrung out, are filled whilst on the Bocks with a filthy 

 Liquor, or rather Jelly-like Matter, which stinks 

 enough to make one sick, even at a considerable 

 Distance. Aristotle supposed them to have some 

 kind of Life from their manner of fixing themselves 

 to the Rocks, whence, says he, it is very difficult to 

 pull them away, unless they are taken as it were by 

 Surprise, for at the Approach of anybody to lay hold 

 on them, they contract immediately and fasten 

 themselves so as not to be removed without a great 

 deal of Trouble. They do the same whenever there 

 are Storms and Tempests. The nasty Matter before 

 mentioned may be supposed given them by Nature 



