Part 2

IV. ASTRONOMICAL AND GEOGRAPHICAL ESSAYS, containing, 1. A full and comprehensive View of the general Principles of Astronomy, with a large Account of the Discoveries of Dr. Herschel, &c. 2. The Use of the Globes, exemplified in a greater Variety of Problems than are to be found in any other Work; arranged under distinct Heads, and interspersed with much curious but relative Information. 3. The Description and Use of Orreries and Planetaria, &c. 4. An Introduction to Practical Astronomy, by a Set of easy and entertaining Problems. Third Edition, 8vo. Price 10s. 6d. in Boards, illustrated with sixteen Plates.

V. AN INTRODUCTION TO PRACTICAL ASTRONOMY, or the Use of the Quadrant and Equatorial, being extracted from the preceding Work. Sewed, with two Plates, 2s. 6d.

VI. AN APPENDIX to the GEOMETRICAL AND GRAPHICAL ESSAYS, containing the following Table by Mr. JOHN GALE, viz. a Table of the Northings, Southings, Eastings, and Westings to every Degree and fifteenth Minute of the Quadrant, Radius from 1 to 100, with all the intermediate Numbers, computed to the three Places of Decimals. Price 2s.

_In the Press, and speedily will be Published_, LECTURES ON NATURAL AND EXPERIMENTAL PHILOSOPHY,

In Five Volumes 8vo. The Second Edition, with upwards of Forty large Plates, considerable Alterations and Improvements; containing more complete Explanations of the Instruments, Machines, &c. and the Description of many others not inserted in the former Edition.

BY W. JONES, MATHEMATICAL AND PHILOSOPHICAL INSTRUMENT MAKER.

_ADVERTISEMENT._

_The editor esteems it his indispensable duty, to point out the several improvements which have been made in this work, in order to render it still more acceptable to the public._

_The whole has been carefully revised--many typographical errors corrected--numerous additions and emendations from the author’s own copy incorporated, and some superfluities rejected. Wherever any ambiguity occurred, the editor has endeavoured to elucidate the passage, observing due caution not to misconceive the idea which the author meant to inculcate. A more regular arrangement has been attempted, and occasional notes subjoined: in these, and in other parts of the work, it has been the editor’s primary object to ascertain facts, not to decide peremptorily. Should he in any instance have erred, he can assure the candid critic, that he shall experience a most sensible pleasure in conviction._

_The principal additions are_,

Accounts of the latest improvements which have been made in the construction of microscopes, particularly the lucernal.

A description of the glass, pearl, &c. micrometers, as made by Mr. Coventry, and others.

An arrangement and description of minute and rare shells.

A descriptive list of a variety of vegetable seeds.

Instructions for collecting and preserving insects, together with directions for forming a cabinet.

A copious list of objects for the microscope.

A list of Mr. Custance’s fine vegetable cuttings.

_With respect to the plates, three new engravings are introduced, viz._

PLATE IV. Exhibiting the most improved compound microscopes, with their apparatus.

PLATE XIV. Microscopical figures of minute and rare shells.

PLATE XV. Microscopical figures of a variety of vegetable seeds.

_Many additional figures have been inserted in other plates, and a number of errors in the references corrected._

_A complete list of the plates and a more extensive index are also added._

_It has been generally understood, that the author intended to have published this edition in octavo; but, the impropriety of adopting that mode must appear evident, for the very reason assigned by the author himself in the concluding part of his preface. If the plates are liable to sustain damage by folding them into a quarto, they would have been subjected to far greater injury by being doubled into an octavo size, besides, being extremely incommodious for reference. As the work now appears, the purchaser may either retain the plates in the separate volume, or, without much inconvenience, if properly guarded, have them bound with the letter press._

_It affords the editor a pleasing satisfaction to mention, that notwithstanding the additional heavy expense incurred in the article of paper, &c. yet, by somewhat enlarging the page, and other economical regulations in the mode of printing, this edition is offered to the public at a trifling advance on the original price, though the improvements now made occupy considerably more than one-hundred pages._

_Anxious, lest the reputation which the work has already acquired, should be diminished by any deficiency on his part, the editor has sedulously applied himself to render it extensively useful to the serious admirer of the wonders of the creation; whether he has succeeded, is now submitted to the decision of the intelligent part of the public. He shall only add, that conscious of the purity of his intentions, and convinced of the instability of all terrestrial attainments, he trusts that he is equally secured from the weakness of being elevated by success, or depressed by disappointment._

_Apothecaries Hall, London,

Jan. 1, 1798._

CONTENTS.

CHAP. I.

A concise History of the Invention and Improvements which have been made upon the Instrument called a Microscope. p. 1.

CHAP. II.

Of Vision; of the optical Effects of Microscopes, and of the Manner of estimating their magnifying Powers. p. 26.

CHAP. III.

A Description of the most improved Microscopes, and the Method of using them. p. 64.

CHAP. IV.

General Instructions for using the Microscope, and preparing the Objects. p. 129.

CHAP. V.

The Importance of Natural History; of Insects in general, and of their constituent Parts. p. 167.

CHAP. VI.

A general View of the internal Parts of Insects, and more particularly of the Caterpillar of the Phalæna Cossus. A Description of sundry miscellaneous Objects. p. 334.

CHAP. VII.

The Natural History of the Hydra, or Fresh Water Polype. p. 357.

CHAP. VIII.

Of the Animalcula Infusoria. p. 415.

CHAP. IX.

On the Organization or Construction of Timber, as viewed by the Microscope. p. 574.

CHAP. X.

Of the Crystallization of Salts, as seen by the Microscope; together with a concise List of Objects. p. 600.

CHAP. XI.

An Arrangement and Description of minute and rare Shells. A descriptive List of a Variety of vegetable Seeds, as they appear when viewed by the Microscope. By the Editor. p. 629.

CHAP. XII.

Instructions for collecting and preserving Insects. A copious List of microscopic Objects. By the Editor. p. 665.

ADDITIONS. p. 713.

ERRATA.

Page 16, line 22, _for_ lead _read_ led

Page 20, line 6, _for_ Fig. T _read_ Fig. 1

Page 49, last line, _for_ usefully _read_ successfully

Page 62, last but one, _for_ stop _read_ stage

Page 80, line 22, _after_ microscope _add_ by

Page 88, three lines from bottom, _for_ improvent _read_ improvement

Page 95, line 2, _for_ R _read_ K

Page 111, two lines from bottom, _for_ VK _read_ VX

Page 115, line 12, _for_ g _read_ q

Page 125, note, _for_ Fig. 13 _read_ Fig. 13*

Page 145, line 17, _for_ cast of _read_ cast-off

Page 153, line 21, _for_ unkown _read_ unknown

Page 169, eight lines from bottom, _for_ is _read_ are

Page 188, note line 9, _for_ preventatives _read_ preventives

Page 195, line 7, _for_ exagon _read_ hexagon

Page 238, line 16, _for_ scarc _read_ scarce

Page 319, line 19, _for_ rise _read_ raise

Page 346, line 18, _for_ bread _read_ bred

Page 354, three lines from bottom, _for_ Fig. 1 and 2 _read_ Fig. 1 and 3

Page 445, line 18, _for_ immediate _read_ intermediate

LIST OF THE PLATES,

WITH REFERENCES TO THE PAGES WHERE THE SEVERAL FIGURES ARE DESCRIBED.

Plate Page

I. Various diagrams illustrative of vision and the optical effect of microscopes 29

II. A. Ibid.--Needle micrometer, 54.--Coventry’s pearl, &c. micrometers 59

B. Fig. 1. Wilson’s microscope and apparatus, 115.--Fig. 2. Ditto with a scroll 117

Fig. 3, 4. Small opake microscope and apparatus 118

III. Fig. 1, 2, and 4. Adams’s lucernal microscope and apparatus 64

Fig. 3. Argand’s patent lamp 69

IV. Fig. 1. Jones’s improved compound microscope and apparatus 92

Fig. 2. Jones’s most improved ditto, ditto 99

Fig. 3. Culpeper’s three-pillared microscope and apparatus 104

V. Martin’s improved solar opake and transparent microscope 106

VI. Fig. I. Withering’s botanical microscope, 123.--Fig. 2. Pocket botanical and universal microscope 124

Fig. 3. Lyonet’s anatomical microscope 122

Fig. 4. Transparent solar microscope and apparatus 113

Fig. 5. Tooth and pinion microscope ibid.

Fig. 14. Common flower and insect microscope note 125

VII. A. Cuff’s double constructed microscope and apparatus 89

B. Ellis’s aquatic microscope 119

VIII. Fig. 1-6. Portable microscope and telescope with apparatus 125

Fig. 7, 8. Botanical magnifiers ibid.

IX. Fig. 1, 2. Engine for cutting sections of wood, and appendage 127

Fig. 3, 4. Jones’s improved lucernal microscope and apparatus 80

Fig. 5, 7. The Rev. Dr. Prince’s and Mr. Hill’s improvements on the illuminating lenses and lamp of the lucernal microscope 84

Fig. 6. Lanthorn microscope and screen 88

X. Fig. 1, 2. Nest of the phalæna neustria.--Fig. 3, 4. Vertical section of ditto.

Fig. 5, 6. Horizontal section 287

Fig. 7, 8. Scales of the parrot fish, 355.--Fig. 9, 10. Scales of sea perch 356

XI. Fig. 1, 2, 3. Larva of the musca chamæleon 248

Fig. 4, 5. Eels in blighted wheat 469

Fig. 6, 8, 9, 10, 11. Paste eel 462

Fig. 7. Vinegar eel 461

XII. Fig. 1, 2, 3, 4. Dissection of the caterpillar of the phalæna cossus 336

Fig. 5, 6, 7. Dissection of the head of the caterpillar 337

XIII. Fig. 1, 2. Beard of the lepas anatifera 344

Fig. 3, 4. Collector of the bee 182

XIV. Fig. 1, 2. Wing of the forficula auricularia 143 and 205

Fig. 2 to 47. Magnified figures of minute and rare shells 629

XV. Fig. 1, 2. Wing of the hemerobius perla 206

Fig. 1 to 46. Microscopic views of a variety of vegetable seeds 645

XVI. Fig. 1, 2, and B, C, D, E. Proboscis of the tabanus 188

Fig. 3, 4. Cornea of the libellula 197

Fig. 5, 6. Cornea of the lobster ibid.

Fig. 7, 8, E, F, H, I. Feathers of the wings of the sphinx stellatarum 208 and 627

XVII. Fig. 1, 2, 3. Leucopsis dorsigera 347

XVIII. Fig. 1 and 6. The lobster insect 348

Fig. 2 and 7. Skin of the lump-sucker 352

Fig. 3, 4, 5. Thrips physapus 350

XIX. Fig. 1-4. Feet of the monoculus apus 354

Fig. 5 and 6. Skin of the sole fish.--Fig. 7, 8. Scale of the haddock.--Fig. 9, 10. Scale of West Indian perch.--Fig. 11, 12. Scale of sole fish 356

XX. Fig. 1 and A. Cimex striatus, 352.--Fig. 2 and B. Chrysomela asparagi 353

Fig. 3 and C. Meloe monoceros 354

XXI. Fig. 1-24. Various hydræ and vorticellæ 364

XXII. Fig. 26-40. Ditto 392

XXIII. A. Fig. 1-13. Various hydræ, 365. B. Fig. 14-29. Ditto 382

XXIV. A. Fig. 1-10. and B. Fig. 11-24. Ditto 376

XXV. Fig. 1-68. A variety of animalcula infusoria 431

XXVI. Fig. 1-23. Ditto 548

XXVII. Fig. 1-66. Ditto 519

XXVIII. Fig. 1, 2. Transverse section of chenopodium 599

Fig. 3, 4. Transverse section of a reed from Portugal ibid.

XXIX. Fig. 1, 2. Transverse section of althæa frutex ibid.

Fig. 3, 4. Transverse section of hazel ibid.

Fig. 5, 6. Transverse section branch of lime tree ibid.

XXX. Fig. 1, 2. Transverse section of sugarcane. ibid.

Fig. 3, 4. Transverse section of bamboo cane ibid.

Fig. 5, 6. Transverse section of common cane ibid.

XXXI. Fig. 1, 2. Crystals of nitre 606

Fig. 3, 4. Distilled verdigrise ibid.

XXXII. Fig. 1. Microscopical crystals of salt of wormwood 607

Fig. 2. Microscopical crystals of salt of amber ibid.

Fig. 3. Microscopical crystals of salt of hartshorn ibid.

Fig. 4. Microscopical crystals of salt of sal ammoniac ibid.

N. B. The reader will find no references to the several letters which appear in the bodies of these figures, for reasons assigned by the author as above; in order not to deface the plate, they were suffered to remain.

ESSAYS ON THE MICROSCOPE.

CHAP. I.

A CONCISE HISTORY OF THE INVENTION AND IMPROVEMENTS WHICH HAVE BEEN MADE UPON THE INSTRUMENT CALLED A MICROSCOPE.

It is generally supposed that microscopes[3] were invented about the year 1580, a period fruitful in discoveries; a time when the mind began to emancipate itself from those errors and prejudices by which it had been too long enslaved, to assert its rights, extend its powers, and follow the paths which lead to truth. The honor of the invention is claimed by the Italians and the Dutch; the name of the inventor, however, is lost; probably the discovery did not at first appear sufficiently important, to engage the attention of those men, who, by their reputation in science, were able to establish an opinion of its merit with the rest of the world, and hand down the name of the inventor to succeeding ages. Men of great literary abilities are too apt to despise the first dawnings of invention, not considering that all real knowledge is progressive, and that what they deem trifling, may be the first and necessary link to a new branch of science.

[3] The term microscope is derived from the Greek μικρος little, and σκοπεω to view; it is a dioptric instrument, by means of which objects invisible to the naked eye, or very minute, are by the assistance of lenses, or mirrors, represented exceeding large and very distinct. EDIT.

The microscope extends the boundaries of the organs of vision; enables us to examine the structure of plants and animals; presents to the eye myriads of beings, of whose existence we had before formed no idea; opens to the curious an exhaustless source of information and pleasure; and furnishes the philosopher with an unlimited field of investigation. “It leads,” to use the words of an ingenious writer, “to the discovery of a thousand wonders in the works of his hand, who created ourselves, as well as the objects of our admiration; it improves the faculties, exalts the comprehension, and multiplies the inlets to happiness; is a new source of praise to him, to whom all we pay is nothing of what we owe; and, while it pleases the imagination with the unbounded treasures it offers to the view, it tends to make the whole life one continued act of admiration.”

It is not difficult to fix the period when the microscope first began to be generally known, and was used for the purpose of examining minute objects; for, though we are ignorant of the name of the first inventor, we are acquainted with the names of those who introduced it to the public, and engaged their attention to it, by exhibiting some of its wonderful effects. Zacharias Jansens and his son had made microscopes before the year 1619, for in that year the ingenious Cornelius Drebell brought one, which was made by them, with him into England, and shewed it to William Borel, and others. It is possible, this instrument of Drebell’s was not strictly what is now meant by a microscope, but was rather a kind of microscopic telescope,[4] something similar in principle to that lately described by Mr. Æpinus, in a letter to the Academy of Sciences at Petersburgh. It was formed of a copper tube six feet long and one inch diameter, supported by three brass pillars in the shape of dolphins; these were fixed to a base of ebony, on which the objects to be viewed by the microscope were also placed. In contradiction to this, Fontana, in a work which he published in 1646, says, that he had made microscopes in the year 1618: this may be also very true, without derogating from the merit of the Jansens, for we have many instances in our own times of more than one person having executed the same contrivance, nearly at the same time, without any communication from one to the other.[5] In 1685, Stelluti published a description of the parts of a bee, which he had examined with a microscope.

[4] Vide Borellum de vero Telescopii Inventore.

[5] In 1664 Dr. Power published his “Experimental Philosophy,” the first part of which consists of a variety of microscopical observations; and in the following year Dr. Hooke produced his “Micrographia,” illustrated with a number of elegant figures of the different objects. EDIT.

If we consider the microscope as an instrument consisting of one lens only, it is not at all improbable that it was known to the ancients much sooner than the last century; nay, even in a degree to the Greeks and Romans: for it is certain, that spectacles were in use long before the above-mentioned period: now, as the glasses of these were made of different convexities, and consequently of different magnifying powers, it is natural to suppose, that smaller and more convex lenses were made, and applied to the examination of minute objects. In this sense, there is also some ground for thinking the ancients were not ignorant of the use of lenses, or at least of what approached nearly to, and might in some instances be substituted for them. The two principal reasons which support this opinion are, first, the minuteness of some ancient pieces of workmanship, which are to be met with in the cabinets of the curious: the parts of some of these are so small, that it does not appear at present how they could have been executed without the use of magnifying glasses, or of what use they could have been when executed, unless they were in possession of glasses to examine them with. A remarkable piece of this kind, a seal with very minute work, and which to the naked eye appears very confused and indistinct, but beautiful when examined with a proper lense, is described “Dans l’Histoire de l’Academie des Inscriptions,” tom. 1, p. 333. The second argument is founded on a great variety of passages, that are to be seen in the works of Jamblichus, Pliny, Plutarch, Seneca, Agellius, Pisidias, &c. From these passages it is evident that they were enabled by some instrument, or other means, not only to view distant objects, but also to magnify small ones; for, if this is not admitted, the passages appear absurd, and not capable of having a rational meaning applied to them. I shall only adduce a short passage from Pisidias, a christian writer of the seventh century, Τα μελλοντα ως δια διοπτρου συ βλεπεις: “You see things future by a _dioptrum_:” now we know of nothing but a perspective glass or small telescope, whereby things at a distance may be seen as if they were near at hand, the circumstance on which the simile was founded. It is also clear, that they were acquainted with, and did make use of that kind of microscope, which is even at this day commonly sold in our streets by the Italian pedlars, namely, a glass bubble filled with water. Seneca plainly affirms it, _Literæ, quamvis minutæ et obscuræ, per vitream pilam aqua plenam majores clarioresque cernuntur_. Nat. Quæst. lib. 1, cap. 7. “Letters, though minute and obscure, appear larger and clearer through a glass bubble filled with water.” Those who wish to see further evidence concerning the knowledge of the ancients in optics, may consult Smith’s Optics, Dr. Priestley’s History of Light and Colours, the Appendix to an Essay on the first Principles of Natural Philosophy by the Rev. Mr. Jones, Dr. Rogers’s Dissertation on the Knowledge of the Ancients, and the Rev. Mr. Dutens’s Enquiry into the Origin of the Discoveries attributed to the Moderns.[6]

[6] A new edition in French of this learned and valuable work, with many and useful notes, is just published. EDIT.

The history of the microscope, like that of nations and arts, has had its brilliant periods, in which it has shone with uncommon splendor, and been cultivated with extraordinary ardour; these have been succeeded by intervals marked with no discovery, and in which the science seemed to fade away, or at least lie dormant, till some favourable circumstance, the discovery of a new object, or some new improvement in the instruments of observation, awakened the attention of the curious, and animated their researches. Thus, soon after the invention of the microscope, the field it presented to observation was cultivated by men of the first rank in science, who enriched almost every branch of natural history by the discoveries they made with this instrument: there is indeed scarce any object so inconsiderable, that has not something to invite the curious eye to examine it; nor is there any, which, when properly examined, will not amply repay the trouble of investigation.

I shall first speak of the SINGLE MICROSCOPE, not only as it is the most simple, but because, as we have already observed, it was invented and used long before the double or compound microscope. When the lenses of the single microscope are very convex, and consequently the magnifying power very great, the field of view is so small, and it is so difficult to adjust with accuracy their focal distance, that it requires some practice to render the use thereof familiar; at the same time, the smallness of the aperture to these lenses has been found injurious to the eyes of some observers: notwithstanding, however, these defects, the great magnifying power, as well as the distinct vision which is obtained by the use of a deep single lens, more than counterbalances every difficulty and disadvantage. It was with this instrument that Leeuwenhoek and Swammerdam, Lyonet and Ellis examined the minima of nature, laid open some of her hidden recesses, and by their example stimulated others to the same pursuit.