ascribed to be confidered as effential, i. e. as refulting from the nature of the objects in which they refide, fince they may be awing to an external cause, which operates in all places to which our obfervation or experience can reach. The particular properties of bodies which diftinguish them from each other, are, according to our Author, firft, certain powers by which they act upon the organs of fenfe, and thus excite different fenfations or perceptions in the foul: fecondly, a capacity of acting upon other bodies, or of being modified by them according to certain permanent laws: thirdly, their differing from each other by a certain contexture or internal ftructure: and, lastly, their being compofed of different kinds of principles, more or less fimple and variously combined. In organized bodies the first bufinefs of the Obferver is, to confider the external qualities which diftinguifh the fpecies; and, in order to determine thefe with precifion, the different parts of each object in the vegetable and animal kingdoms must be examined with attention in their conformation, number, arrangement, proportions, colour, and the fenfations they produce when applied to organs of touching, fmelling, and tafting. Our Author illuftrates this by inftructive examples, and fhews how the obferver arrives thus at a diftin&t notion of the general conformation of each object fo as to diftinguifh its fpecies, in many cafes, at the firft view. However, to render organized bodies more eafily difcernable by the generality of mankind, the most popular and obvious marks and characters, even fuch as may be perceived without the affiftance of glaffes, muft be attended to as much as is poffible, without neglecting the examination of feveral of their external parts that are only perceivable by the help of the microscope. To these characteristical marks must be added the confideration of the element in which they exift, their duration, &c. In all these researches our Author cautions the obferver against regarding, as fpecific and effential, the differences, however permanent, that the climate alone produces in plants and animals of the fame nature, and he fhews particularly how the fpecies may be discerned and afcertained even in the midft of thefe diverfities. Father Sainovics, a native of Hungary, who went to Lapland with Father Hell to obferve the paffage of Venus, has proved with the utmost evidence that the language of the Laplander is the fame with that of the Hungarian; now it is well known that the Hungarian language refembles that which is spoken by feveral nations in Tartary, and this is an indication that the LapJanders and Hungarians are of Tartar origin, though the former by their paffage into a different climate have degenerated in their size and external form. The The difficulties which the Obferver meets with in the anatomy of animals and the organization of plants,—the methods of overcoming them,-the dexterity and art that are neceflary to make nature tell her fecrets; and the curious inventions that are adapted to unfold to view thofe minute and fubtile parts in her productions, that are inacceffible by the unaffifted fenfes, are the objects that next employ our Author.. Here the ufe of inftruments, injections, macerations and the various kinds of preparations that are neceffary to lead us to the knowledge of the hidden qualities of bodies are particularly confidered; as alfo the cafes in which all these preparations may be unfaithful guides, and the precautions to be employed in order to prevent their becoming fuch. But here it is not poffible to lay down. the general rules, whofe application wiil extend to every particular of cafe. This defect must be fupplied by the ardent thirst after From organized bodies Mr. CARRARD paffes to un-organized In confidering the artful methods and wiles (if we may use that expreffion) that the Obferver muft employ to discover several properties, that conftitute the specific characters of bodies, and to determine the laws by which they act or are acted upon, our Author paffes in review the labours of the experimental philofopher and the chemift, fhews the refult of their researches, by a great variety of interefting examples, and points out the dexterity and difcernment that are neceflary to render their inveftigations fuccefsful. He fhews the attention which the Obferver muft pay to the circumftances in which different bodies exert their powers, in order to the comparing these powers with each other, and the afcertaining the accuracy of the refults that are derived from this comparison. He indicates the proper use of analogy in difcovering the properties of fubLances, that are either new or little known, evinces by several curious examples, the neceffity of repeating and diverfifying Kk 4 the which bodies, esil 3/ the fame experiments, in order to discover the properties of bodies, or the effects which refult from their reciprocal action; and fhews how, by expofing bodies to their reciprocal action, we may come to the knowledge of the characteristical marks by which they are diftinguished. A lucky chance fometimes ftrikes out fingular discoveries, and unfolds to the Obferver properties in certain bodies, of which he could not have formed the most diftant expectation; but (as our Author remarks justly) fuch discoveries are seldom unfolded to any but those who deserve to meet with them; and who, by following attentively the clue of their deep researches, affail, if we may ufe that expreffion, the object of their obfervations on fome new fide, or by fome particular procedure, which presents to them properties, different indeed from thofe which they had in view; but which would have remained unknown to those whose researches were carried on with lefs fagacity and invention. In order to arrive at the most compleat and adequate knowledge of bodies that is attainable, it is neceffary to decompose them; and feparate by chemical operations, the different kinds or claffes of principles, that enter into their composition; and our Author enumerates, with great precifion, the diffolvents by which this analyfis is performed, the manner of employing them, and the circumfpection and precautions with which the Obferver must admit the refults which are furnished by this analyfis. He fhews also how ufeful the analyfis, or decompofition of bodies, notwithstanding its imperfection, is to come at the knowledge of their origin, and to prevent our being deluded by falfe appearances. After having mentioned the requifites that qualify an Observer to examine with fuccefs, the ftructure and conftituent parts of organized and animal bodies, Mr. CARRARD thews how they must be obferved under another aspect, even as beings endowed with an active principle, which animates them to pursue or avoid certain objects. Here, indeed, the fubject of investiga tion is nice and fubtile; and the danger of falling into error, through hafty conclufions from certain appearances, is every way adapted to excite circumfpection. The Obferver is tempted to attribute fenfibility to certain plants, on account of the fingularity of their motions, which may be merely mechanical, and to refufe it to certain animals on account of their torpid and motionlefs ftate, which may, nevertheless, be fufceptible of a certain, though feeble degree of perception and fenfation: he may exalt too much the principle of intelligence which dijects the labours of the incuftrious bee; or, to avoid this error, he may fall into the contrary extreme, and rob the little animal of the meafure of underftanding which really belongs to it. The rules and directions which our Author prescribes as a prefervative against illufions of this kind, are judicious and excel lent. lent. He fhews how the Obferver muft ftudy the natural language of animals, in order to difcover their fenfations, the dexterity, precautions and artifice he muft employ to difcern their industry, and the police of fuch of them as herd together and live in fociety ;-the means he must use to get fome infight. into the myfterious principle that directs the emigrations of certain birds; the care he must take to ftudy the accents and motions of animals;-the gentle violence he may fometimes employ to difconcert them in their operations, in order to fee their refources, and difcover manœuvres, which would otherwife have escaped his notice, but alfo the patience and management, with which he muft, generally fpeaking, let them purfue the line of their operations, left interrupting unfeafonably their activity, he should fufpend the exertion of their faculties, and thus be hindred from difcerning the extent of their powers. As the obfervation of infects is attended with great and peculiar difficulties, our Author enumerates thefe difficulties, and prefcribes the methods that are to be employed in furmounting them. But as man is at the head of the animal creation, and is endowed with a principle of intelligence fuperior, probably in kind as well as in degree, to that which directs the motions of other fenfitive beings on this globe, he is the most important object of inquiry to the true philofopher. Accordingly, Mr. CARRARD gives a particular account of the most effectual manner of arriving, by obfervation, at an extenfive, though not compleat knowledge of the human mind. Here the Obferver must attend, above all things, to the correspondent mo tions, fenfations and affections of mind and body; and arrange the facts that come under this correfpondence in the order in which they have happened, as this will enable him to account for many things in the nature and operations of the human mind, that would be otherwife inexplicable: thus, by confidering what paffes in the organ of fight and in the mind; when the latter acquires the idea of light or of the colour of an object, we can eafily account for our perceiving light or colours in the deepest darkness, in confequence of a blow received fuddenly on the eye, or a voluntary preffion of the corner of that organ; and, in the fame manner, the phenomenon of dreaming may be explained, by the ordinary mechanim of the impreffions of external bodies on our organs, and their correfpondent fenfations. Mr. CARRARD thinks that by a due attention to the correfpondent motions and fenfations of body and mind, chirurgical operations may be rendered capable of removing the obstacles that reftrain the free exercife of the intellectual faculties in ideots and others; and he tells us the story ftory of an ideot, who by a fall, that fractured his skull, became, in a little time as fagacious and fenfible as his neighbours. The story is authentic, and is taken from the Memoirs of the Academy of Sciences at Paris. To fucceed in his refearches, with refpect to the nature and properties of the human mind, the Obferver must carefully compare what paffes within himself with what he has learned from hiftory or converfation, with refpect to other men in remote ages, in diftant regions, and alfo with refpect to thofewho actually live in the fame community of which he is a member. This will enlarge the mind, remove narrow prejudices, and fhew how the fame fund of effential principles, ideas, and paffions, is modified into amazing diversities, by an infinite variety of circumftances; and no method, perhaps, of contemplating human nature is fo important and inftructive as this, as none difcovers more its effential conftitution, and enables us better to diftinguish it from the motley affociations that education, example, habit, fituation, and other incidental objects have blended with it. To finish this article of the knowledge of human nature, and with it the first chapter of this work, our Author shews that it is necessary to analyfe the operations of the mind, and to confider separately and diftinctly its different faculties; he lays down alfo the principles from which the Observer muft deduce our duties to God and man; and points out the objects that must attract his attention in the various forms of government and the different fyftems of legiflation, confidered in their tendency to improve or corrupt the human mind. Having thus pointed out the fpirit and method of inquiry, which the Obferver must bring with him in his examination of the properties of different beings, Mr. CARRARD goes on in his fecond chapter, to fhew how he must proceed in order to obferve the courfe and procedure of nature, in the changes whtch happen in the world. Here he supposes his Obferver furnished with a fufficient knowledge of geometry and mechanics, to estimate quantities, to contrive experiments, and to calculate their refults; and then he reduces to the following articles (which are illuftrated in a moft curious, ample, and interefting detail), the requifites for obferving the procedure of nature in the new fphere of contemplation, expreffed in the title of this chapter. The ft is, that in obferving any change that happens in nature, it must be traced to its origin, and viewed in the various fteps of its progrefs;-it is by this method of proceeding, that the change of the caterpillar into a butterfly ceases to appear a real transformation, and it is thus that we come to difcern the true procedure of nature; which, under the direc |