« PreviousContinue »
of heat, by means of friction, which has with the greatest plau. fibility been insisted on by several modern physiologists
, is shewn not to be applicable to the animal body, from the unaptness of its folids and fluids to produce such a degree of attrition as is found neceffary in other cases to occasion heat. A thort fection is next bestowed on Dr. Cullen's solution of this question; if, indeed, that can be called a solution, which is only a reference to fome occult principle of the animal ceconomy, not analogous to any thing known. The vital principle, according to this celebrated Profeffor, may have such a peculiar power, that where it is different, different degrees of heat may be generated
, though the velocity of the blood be the fame. But, as Dr. Leslie remarks, to say that the principle of life can generate heat or cold, independent of chemical or mechanical means, is contrary to experience, and seems in itself absurd.' The salt theory examined by our Author is that of Dr. Black; who fup. poses, that animal heat is all generated in the lungs, by the action of the air on the principle of inflammability, and is thence diffused over the rest of the body by means of the circulation. - Several arguments are adduced against the truth of this ingenious hypothesis, which is thewn to be repugnant ta, the known laws of the animal machine.
Dr. Leslie next proceeds to lay down his own idea on the fubject. This is that the subtle principle, by chemists termed phlogiston, which enters into the composition of natural bodies, is, in consequence of the action of the vascular system, 'gradually evolved throughout every part of the animal machine, and that
, during this evolution, heat is generated.' This opinion, be says, was first explicitly delivered by Dr. Duncan of Edinburgh; but that somewhat very near it is to be found in Dr. Franklin's works, and in a paper of Dr. Mortimer's in the Philosophical
Transactions. He endeavours to establish it by the following well-connected chain of argumentation, ift, That the blood contains phlogiston : 2d, That the action of the blood-vessels evolves phlogiston: 3d, That the evolution of phlogiston is at: tended with heat: 4th, That the heat thus generated is fufficient to account for the heat of living animals: 5th, That the most striking phænomena of animal heat evince the truth of these-propositions.
That the blood contains phlogiston, is readily proved by the consent of all modern chemists, who make this principle a component part of every animal matter; and particularly by a decifive experiment of Dr. Priestley's, who found that pieces of the craffamentum of sheep's blood, put into dephlogisticated air, imparted so much phlogiston to it'as to render it unfit for respiration,
That the action of the blood-vessels evolves phlogifton, is a proposition scarcely capable of demonftration, and with respea
to which, therefore, we must be contented with probable arguments drawn from concurring facts. Those which our
Author principally dwells on are, That phlogiston is the chief ingredient in all alimentary fubstances; that a chemical analysis evinces its presence in the blood; that it is the principle of taste and colouring matter in the bile; that the chyle, after being for a short time subjected to the action of the vessels, becomes of a deep red colour; and that the halitus, which escapes from blood newly drawn, and the vapour fying off from every part of the body, consist chiefly of the principle of inflamma
In proceeding to thew that the evolution of phlogiston is attended with heat, the writer takes a very extensive view of his subject, discussing the mechanical and chemical doctrines of fire, and endeavouring to reconcile them with each other. He attempts to prove that phlogiston is the cause of concretion, and that in every process of resolution there is an escape of this principle. He treats on the identity of the phlogistic fuid and the electric, the matter of light, and the ether of Newton, He shews, that in the several ways of exciting heat, by ignition, fermentation, and chemical mixture, phlogiston is evolved, and its evolution is the probable cause of the heat. This is a long and curious chapter, and evinces an intimate acquaintance with some of the abftrufest parts of natural philosophy.
The chief argument adduced to evince that the heat generated by the evolution of phlogiston from the blood is the fole: cause of animal heat, is derived from the simplicity observable in the laws of Nature, who is never found to employ more agents than are necessary to effect her purposes. That the agitation and compression the blood undergoes in the veftels would promote the developement of its phlogiston, by causing an intestine motion in its constituent parts, is rendered probable by analogous facts. In this chapter the Author declares his belief, that phlogiston is the chief pabulum of animal life, and the grand principle of muscular motion, as well as the only source of vital heat.
In the concluding chapter it is attempted to be shewn, that the most striking phænomena of animal heat evince the truth of the theory proposed. Here, the Author first treats of the connexion of animal heat with the state of motion in the fan-. guiferous fyftem ; and obviates some objections to his doctrine which might arise from observing that quickness of pulse is not always attended with increase of heat. He then discusses that difficult subject, the stability of animal heat; and here, being obliged not to admit any power of creating cold resident in the 3
animal machine, which fome late philosophers have attempted it to establish, he canvafles, at fome length, the extraordinary ex.co periments which have been published, relative to the power of mode supporting degrees of heat vastly fuperior to that of the human body. He points out, with the justest criticism (as we think), several fallacies in the deductions drawn from these celebrated hmoi experiments; which chiefly turn upon not having taken into in the confideration the different time required by different bodies to trinh rise to their temperature, the different degrees of heat they are capable of imbibing, and the difference in bulk of the malles zbrant which were exposed to the same heat. His own solution of the ftability of animal heat in various temperatures is, that in the
fured hot, a balance is preserved by the cooling effects of evaporation;
12กรไม่ and in the cold, by the tonic and stimulant effects of cold air posted on the animal fibres. Lastly, he briefly explains on his prin ribe ciples the connection between the degree of animal heat, the ftate of respiration, and the colour of the blood,
and 1 Thus have we given a concise view of the general doctrine and method of proof in this very ingenious work; the great variety of matter in which, however, renders a complete analysis
of the searcely practicable within the bounds we prescribe to ourselves
. This, beside, is the less necessary, as we imagine few of our philofophical readers will be satisfied without a perufal of the meda work itself.
Whether or no such a perusal will produce a full i sepu conviction of the main doctrine attempted to be established in
cubi it, we cannot determine ; but we will venture to pronounce, that it cannot fail of inspiring a very favourable idea of the (cientific and literary abilities of the Writer,
li FOREIGN LITERATURE. (By our CORRESPONDENTS.)
HOLLAND. 4 Anmerkingen op de Tegenwoordige Toestand van Zaaken, 8c
i. e. Observations on the present State of Affairs between Enge land and Holland. 1779. This pamphlet, anonymous both with respect to its Author and the place of publication, comes to us from the Hague, where, we are told, it was printed some weeks ago. It contains a judicious and candid state of the points, at present contested between England and Holland, and carries, in the elegant fimplicity of its ftyle and manner, evident marks of its coming from no ordinary pen. The Author fets the perfidious conduct of the French ministry, and the bold iniquity of their American connexions, in a palpable and striking light, but without either animofity or invective: he thews the Dutch -how ungracious, unfriendly, and unjust it is to ad
here rigorously to the fourth article of the treaty of 1674 (without attending to fubsequent and more essential engagements),
and on the strength of it to furnish France with navål stores: 1. and he demonstrates the prejudice, that must ensue from hence
to their own effential interests in the issue of things. His The Danguage, 'here, is that of a real friend to two countries, whom
religion, liberty, and national character ought to bind together in the nioft indissoluble union; whose independence can only
be insured by that union, and whom nothing but the greateit 12 imprudence can engage to prefer temporary and subaltern 1 advantages to a connection that ascertains their most effenfilm tial interests. 'A connoisseur in the Dutch language has al& fured our Editor, that this pamphlet has all the marks of a for translation from an English original ; adding, that it is fupa it' posed to have come from the pen of a public minister of distinook guished merit at the Hague. A decent tone of dignity, that also runs through the composition, renders this conjecture probable,
and the concluding words of the pamphlet confirm it; they etat are as follows-- or to the following purpose : “ The treaties ho subsisting between Great Britain and Holland stand not in need leti of the intervention of France to explain them. Neither of the me contracting parties have called in that power as a mediator; far and until they do so, his Most Christian Majesty has no right to
meddle in their affairs. --The King of Great Britain loves the republic, efteems its chief; wishes peace and prosperity to its subjects, and stability and independence to its present constitution: he has always been, and ever will be ready to maintain that constitution to the utmost extent of his engagements, and he can do this with a power at least equal to theirs who endeavour to undermine it. This virtuous prince can never be suspected of any design to make an improper use of this power: hé prefers the language of friendship to every other mode of persuasion ; but, nevertheless, it is both the duty and interest of his allies to consider serioufly the unhappy consequences that may follow from facrificing ancient connections to a low and transitory interest, or to sudden movements of impatience and passion. As an Englishman, a Hollander is dear to me, and I shall willingly listen to his just complaints; but if he
adopts, in this time of war and contest, the tone, the interests, . and the measures of France, then he cannot justly blame me, if
I make no difference between him and my enemy." . Ex ungur Leonem.
For M A Y, 1779.
of a Quadrant of Difference of Latitude and Departure ; and an
HIS performance, with its title-page and preface, confits of üb 28
pages of letter-press, and a copper-plate, said to be in. vented by the Author, Mr. James Rymer. Inventions ought c*tainly to be paid for, and fair and candid reports ought to be made of them to the Public: but as we find ourselves rather at a loss rubat account to give of this new invention, and apprehending that the Author can have no objections to his own; the candid Reader is therefore desired to accept it, verbatim, as follows:
• If this little treatise has any merit, the world will soon discover it. If it has none, it might be ancharitable to treat it with coatempta
A I dedicate its utility to the young and ignorant; and folicit indul
. gence from men of science and genius. "If I pretended to raise in value by depreciating books which contain systems of mathematical navigation, I should hold myself guilty of irreverence and dis
. respect to the memory of many great and worthy names.
* Indeed, I should do wrong to recommend, much more to extel it, any farther than it proved of utility to myself, when the scheme firft occurred to me. At that time I had not the smallest systematical knowledge in navigation; and often wondered at my own ignorance, when I reflected on the length of time that I had been at sea. I had often heard them talk of difference of lacicude and departure, allow. ance for lee-way, variation of the compass, heave of the sea, the action of sides and currents, without in the least comprehending what was meant. All of a sudden, one day, at fea, I was determined
, by some means or other, to learn how to work a day's work, and keep a reckoning. I got a Daily Afiftant, a Mariner's Compass, a Robertson's Elements, &c. and applied myself diligently for about two hours when my head began to ach, and my ideas became confused : I put away the books--yauned-scratched my temples-went to bed-raved-and, the present work is the result of the dreams of thái night. Whoever doubts what I affert, does nie an injury : bar, as I allow of an universal toleration of belief and sentiment in all trivial matters, I can readily forgive him.'
This Author's account of his work is not of the common caft; and our Readers will form what judgment they think propes
of it. For our own parts, as we with neither to have the extent of our faith called in question, nor to be laughed at for our credulity, we hall not say yea or nay co this folemn asseveration, but content