who was fenfibly touched by his fon's devotion to his will, and who thereby left him at liberty to follow his own inclinations. From that moment he gave himself up with more ardour than ever to the study of mathematics, continuing that alfo of the living and dead languages.

Spallanzani was prefently known all over Italy, and his own country was the first to do homage to his talents. The university of Reggio, in 1754, chofe him to be profeffor in logic, metaphyfics, and Greek. He taught there for ten years; and during that period confecrated all the time he could fpare from his le fons to the obfervation of nature. Now and then an accidental discovery would increafe his paffion for natural history, which always augmented by new fucceffes. His obfervations upon the animalculæ of infufions fixed the attention of Haller and of Bonnet; the latter of whom affifted him in his glorious career, and thenceforth diftinguished him as one of the learned interpreters of nature.

In 1760 Spallanzani was called to the university of Modena; and although his intereft would have made him accept the advantageous offers of the university of Coimbra, of Parma, and of Cefena; yet his patriotism and his attachment to his family confined his fervices to his own country. The fame confiderations engaged him to refufe the propofitions made him by the academy of Petersburg fome years after. He remained at Modena till the year 1768, and he faw raifed by his care a generation of men conftituting at this time the glory of Italy. Among them may be counted Venturi, profeffor of natural philofophy at Mo. dena; Belloni bishop of Carpi; Lucchefini, ambaffador of the late king of Pruffia; and the poet Angelo Mazzo of Parma.

During his refidence at Modena,

di Offervazioni Microfcopiche concernente il Sistema di Needham e Buffon, He therein establishes the animality of what had been called, but not generally affented to, as microfcopic animalculæ, by the most ingenious, and at the fame time folid, experi ments; he fent this work to Bonnet, who formed his opinion of the author accordingly, and who lived to fee the accomplishment of the prophecy he drew from it. From that moment, the most intimate acquaintance was formed between them, and it lafted during their lives, of which it conftituted the chief happiness. In the fame year Spallanzani published a dif fertation truly original: De Lapidibus ab Aqua refilientibus: in that work he proves, by fatisfactory experiments, contrary to the commonly received opinion, that the ducks and drakes (as they are called) are not produ ced by the elafticity of the water, but by the natural effect of the change of direction which the ftone experiences in its movement, after the water has been ftruck by it, and that it has been carried over the bend or hollow of the cup formed by the concuffion.

In 1768 he prepared the philofophers for the furprifing difcoveries he was about to offer them throughout his life, in publishing his Prodromo di un Opera da Imprimerfi fopra le Riproduzioni Animali. He therein lays down the plan of a work which he was anxious to get up on this im portant fubject; but this fimple profpectus contains more real knowledge than all the books which had appeared, becaufe it taught the method that ought to be followed in this dark research, and contained many unexpected facts; fuch as the pre-exiftence of tadpoles at the fecundation, in many fpecies of toads and frogs; the reproduction of the head cut off from fnails, which he had already communicated to Bonnet, in 1766,

and

and which was difputed for fome time, in fpite of the repeated confirmation of this phenomenon by Heriffant and Lavoisier. He demonftrated it again afterwards in the Memorie della Societa Italiana; as also the renewal of the tail, the limbs, and even the jaws, taken from the aquatic falamander. Thefe facts continue to astonish even at this day, when they are thought of, notwithstanding every one has had the opportunity of familiarifing himself with them: and we hardly know which we ought moft to admire, the expertnefs of Spallanzani in affording fuch decifive proofs, or his boldness in fearching after them, and feizing them. We have to regret that the project of his great undertaking is not realized, but various circumstances prevented him from giving way to the folicitations of his friends for its accomplishment. I fhould fufpect that he defpaired of throwing upon every part of it all the light which at first he thought he might be able; and that he found it prudent to mature his ideas by new meditations: this, perhaps, may have been as powerful a caufe, as that other calls and occupations, perpetually accumulating, fhould not have allowed him to purfue it as he had intended. He has always laid nature open to full view, and the thinnest veil darkened her till he fucceeded in removing it altogether.

The phyfiology of Haller that Spallanzani ftudied, fixed his attention upon the circulation of the blood, in which he discovered feveral remarkable phenomena. He published, in 1768, a small tract: Dell' Azione del Cuore ne' Vafi Sanguigni nuove Offervazioni, and he reprinted it in 1773 with three new differtations, De' Fenomeni della Circolazione offer vata nel Giro univerfali de' Vafi ; de' Fenomeni della Circolazione Languente; de' Moti del Sangue independente del Azione del Cuore e del Pulfare delle Arterie. This work, but little known,

contains a feries of obfervations and experiments, of the most ingenious and delicate nature, upon a fubject of which the furface only is known. This work merits the attention of thofe who are interested in the progrefs of phyfiology.

When the university of Padua was re-established upon a larger fcale, the emprefs Maria Therefa directed the Count de Firmian to invite him to fill a chair, as profeffor of natural hiftory; his great reputation rendered him eligible for this diftinction, folicited by many celebrated men, and he merited it by his fuccefs, and by the crowd of ftudents who thronged to his leffons. Only great men make excellent mafters, because their ideas are the most perfpicuous, the most extenfive, and beft connected.

The

Spallanzani united a vast extent of knowledge to a fine genius ; a method fimple, but rigorous in its nature, and he connected what he knew to principles firmly established. His ardent love of truth made him difcufs, with the utmost care, the theories which prevailed; to found their folidity, and difcover their weak fides. great art which he had acquired, of interpreting nature by herself, diffufed fuch a light over his leffons as made every thing perfpicuous that was capable of affording inftruction. An eloquence at once plain and lively animated his difcourfe; the purity and elegance of his ftyle charmed all who heard it: in fhort, it was known that he always occupied himself about the means of rendering his leffons ufeful, which he prepared a year beforehand. They became always new and engaging, by his new obfervations, and by the enlarged views that his meditations prefented to him. The learned perfons who attended his lectures were pleafed to become his fcholars, in order to know better what they already knew, and to learn that which otherwife they would perhaps never have known,

In

In arriving at the univerfity, Spallanzani took the Contemplation de la Nature of Bonnet for the text of his leffons he filled up the vacancies in it, he unfolded the ideas, and con. firmed the theories by his experiments. He believed with reafon, that the book which infpired him with the love of natural history by reading it, was the most proper to give birth to it in the minds of his difciples.

He tranflated it into Italian, and enriched it with notes; he added a preface to it, wherein he pointed out the fubjects of the vegetable and animal economy, which in an efpecial manner deferved the attention of his pupils and fometimes pointing out to them the means of fucceeding in their researches. It was thus he at frft devoted himself to the pleafing employment of inftructor of his countrymen, and that he became the model of those who were delirous of inftructing ufefully. He published the first volume of his tranflation in 1769, and the fecond in 1770.

The connexion of Spallanzani with Bonnet had an influence upon his genius, which bent to the fevere method of the philofopher of Geneva. He prided himself in being his pupil, and he unceasingly meditated upon his admirable writings; and thus it was that he became defirous of feeking in nature for the proofs of Bonnet's opinion upon the generation of organized bodies, and that this charming fubject fixed his attention for a long time.

He publifhed, in 1776, the two first volumes of his Opufcoli di Fifica Animale e Vegetabile: they are the explanation of a part of the Microscopic Obfervations, which had already appeared.

If the art to obferve be the moft difficult, it is nevertheless the most neceffary of all the arts; but it fuppofes every quality, every talent: and further, though each believes himself more or less confummate

therein, yet it is obvious that only great men have exercifed it in a dif tinguished manner. Genius alone fixes the objects worthy of regard; that alone directs the fenfes to the obfcurities which it is neceffary to diffipate; it watches over them to prevent error; it animates them to follow by the fcent, as it were, that which they have but a diftant view of: it takes off the veil which covers what we are looking after; it fupports the patience which waits the moment for gratifying the fight in the midst of obftacles multiplying one upon another: in fhort, it is genius that concentrates the attention upon an object, which communicates that energy to him for imagining, that fagacity for difcovering, that promptnefs for perceiving, without which we fee only one fide of truth, when we do not happen to let it ef cape altogether. But this is not all; for after nature has been read with precifion, it is neceffary to interpret her with fidelity; to analyfe by the thought the phenomena anatomifed by the fenfes; to confider of the species by obferving the individual, and to anticipate the general propofitions by confidering the unconnected facts. Here, prudence and circumfpection will not always fecure us against error, if an ardent love for the truth does not affay observations and their confequences in its crucible, and thereby reduce every thing to fcoria which is not truth.

Such was Spallanzani in all his refearches; fuch we fee him in all his writings. Occupied by the great phenomenon of generation, he examined the opinion of Needham to demonftrate its want of foundation: the latter, not fatisfied with the microfcopic obfervations of Spallanzani, which weakened the imagined vegetative force to put the matter in mo tion, challenged the profeffor of Reggio to a reperufal of what he had written; but he proved to the other,

that

that we in common practice always fee that which has been well obferved, but that we never again fee that which we have been contented with imagining we faw.

I make no remark on the fevere logic and amiable politeness of Spallanzani in his refutation, or the art with which he demonstrates to Needham the causes of his error; but it will always be understood with pleafure, that the animalcula of infufions are produced by germs, that there are fome of them which defy, like certain eggs and feeds, the most exceffive cold, as well as the heat of boiling water. On this occafion he treats on the influence of cold upon animals, and proves that the lethargic numbness of fome, during winter, does not depend upon the impreffion the blood may receive from it, fince a frog, deprived of his blood, becomes lethargic when he is reduced to the fame cold ftate by an immerfion in ice, and fwims as before when reftored to warmth. In the fame manner, he fhews that odours, various liquors, the vacuum, act upon animalculæ as upon other animals, that they are oviparous, viviparous, and hermaphrodite. Thus, in running over these distant regions of nature with this illuftrious traveller, we are always meeting with new facts, profound remarks, precious details, and fome curious anecdotes; in fhort, an univerfal history of thofe beings which are the most numerous of the globe, although their existence is fcarcely fufpected, and whofe organization is in many refpects different from that of known animals.

The fecond volume of this work is a new voyage into the most unknown parts; a fublime pencil had already painted it, but the picture was not done after nature. Spallanzani here gives a history of the fpermatic animalculæ, which the eloquent hiftorian, above alluded to, always confounds with the animalcula of infu

fions. We cannot but admire the modest diffidence of this new domonftrator, ftruggling against his own opinion and the authority of Buffon; and he appeals to admit with repugnance the refults of his multiplied and in a thousand ways varied obfervations, which expofe the feeblenefs of the fyftem of organic moleculæ.

Spallanzani afterwards defcribes the volvox and the flow-moving animalcula (rotifere and tardigrade) thofe coloffufes of the microscopic world, fo fingular by their figure and organization, but more fingular still by their faculty of refuming life, after a total fufpence of all the apparent acts of it during many years.

I do not here fpeak of the experiments of Spallanzani on the death of animals in clofe veffels, because he took up the fubject again; and enlarged and exemplified it by the new lights of chemistry; but this collection he concludes with another on the hiftory of vegetable mould growing on the furface of liquors and moift fubftances, the feeds of which he fhews to float in the air; and he remarks that thefe microscopic champignons, or mushrooms, diftinguish themfelves from other plants by their tendency to grow in all directions, without conforming to the almost univerfal law of perpendicularity of stalk to the ground.

Spallanzani was placed at the head of the univerfity's cabinet of natural history, but he was little more than titular depofitary of a treafure which no longer exifted. He laid the foundations however for its renewal, and, by his care, it is become one of the moft precious and useful. He enriched it through his repeated travels by land and fea, in Europe, in Afia, across the Apennines, the Alps, the Krapacks, at the bottom of mines, on the top of volcanoes, at the mouth of craters: fupported by his ardent paffion in the midst of perils, he preferved the fang-froid of the philofo

pher