thefe artificial methods, would be a valuable acquifition to the gardener's library. It is needlefs to fay by whom we wish to fee it executed. ART. VI. Obfervations on the Doctrine laid down by Sir William Blackstone refpecting the Extent of the Power of the British Parliament, particularly with relation to Ireland. In a Letter to Sir William Blackftone; with a Poftfcript addreffed to Lord North, upon the Affairs of that Country. 8vo. Is. 6d. Almon. WE 1779. E have fuffered this pamphlet to flumber peaceably on our shelf beyond the time in which we generally announce political publications, because we apprehended that it turned lefs on political than on legal topics, and because we confider that law will, in general, keep longer than politics, which are of a more fleeting and tranfitory nature. On a more attentive perufal, however, of the arguments it contains, we are rather inclined to clafs it under the latter defcription. Though we entertain no doubt that this publication comes from a lawyer's pen, it will be found that the pofitions which Sir William Blackftone has advanced, and which this Writer has chofen to difcufs, are independent of legal inferences, and admit of little legal controverfy. Our laws certainly acknowledge no higher authority than that of parliament. Here refides the abfolute power of "making, confirming, enlarging, restraining, abrogating, repealing, reviving, and expounding laws concerning matters of all poffible denominations, ecclefiaftical or temporal, civil or military, maritime or criminal." Whatever epithet be thought defcriptive of this high power, it cannot alter its effential properties; much lefs can its existence be difproved by afferting a poffibility of its being abufed. If Sir William Blackftone, in displaying its nature and extent with a laboured pomp of words, has unfortunately provoked this Writer's fpleen, we muft obferve that the learned Commentator is fafely entrenched behind the authority of the most respectable Whigs, and warmeft admirers of the conftitution. It is an inftance of the caprice of all fublunary things, that the fame language which was popular in one age becomes in another fufpected and obnoxious. In the laft century, the power of parlia ments was the palladium of English liberty, and the favourite theme of Englishmen. It was not imagined that a parliament could ever be faithless to the interests of the people, and therefore the conftitution has not provided any check in such a case, beyond the ordinary remedy placed in the hands of the elective body, on every new election of reprefentatives. A change of fituation may, no doubt, induce a change of language, along Black. Comm. Book I. C. 2. with with a change of doctrine; but they who adhere to the old ought not to incur the cenfure of those who adopt new systems or opinions. There is fo much wifdom difplayed in the frame of our government, and the different parts of legiflation are adjufted to each other with fuch a happy nicety, that the higheft. encomiums will not feem hyperbolical. They who wish to see it perpetuated, can hardly be blackened by all the eloquence, and more than all the argument which this Gentleman has em ployed against Sir William Blackftone. We trust the people of this country will always have fenfe to feel, and spirit to defend their rights, under whatever forms the attack may be mafqued. But if ever they should be fo far exasperated at the conduct of their parliaments, as to ftrike them out of the book of political life; what they would gain by fuch a revolution is rather matter of experiment than of theory. Whether the conftitution would be reformed, or whether it would be fubverted, is an arduous point, at which the wifeft men may well paufe, and about which the moft patriotic may be divided. The Commentator on the Laws of England has a right to pronounce his opi nion, and may furely be pardoned for venturing to affirm, that as long as the English conftitution lafts, the power of parliament is abfolute, and without controul." The motives, however, on which he is fuppofed to have efpoufed this doctrine, are difcovered by our Letter-writer with a great deal of goodnatured penetration. "You and I, Sir William, know, that the doctrine of the omnipotence of parliament is a very favourite one in the quarter of promotion: and it was very natural you fhoul prefer a feat on the woolfack to one in the House of Commons." This is one of the triteft artifices of controverfy. Sir William Black ftone is here accused of a bafe and infamous defign to mislead the understandings of his countrymen, on the most important of all subjects, merely because it gives spirit and poignancy to the ftyle of a difputant to fuppofe it as if to confute a man's arguments it was neceffary to wound his character, We are more furprifed to find occafion for this remark given by a writer of learning and genius (for fuch the Author of this letter difcovers himself to be), as he appears to us to have gone out of his way to make the attack. His favourite object, which is to prove the independency of the Irish parliament, ftands clear of this part of the learned Commentator's pofitions. He might have admitted, confiftently with the tenor of his arguments, that the power of the English parliament is fupreme and unbounded within this kingdom (as invefted with all the powers which the community it reprefents can bestow), and at the fame time have denied, as he afterwards does, its legiflative power over a different community which has a parliament of its own. This latter pofition he endeavours to establish by a long and elaborate elaborate investigation of the principles of government; but the fubject has been fo completely exhaufted in the American controverfy, that we find no new light here thrown upon it.-Mr. Burke fomewhere fays, that it is not eafy to make a monopoly of theorems and corollaries:" The Irish are too quick-fighted not to perceive that the arguments employed by America are ready-made to their hands; and if they do not apply them to their own cafe, it certainly is not the fault of their writers. Among the able advocates that have started up in their caufe, what precife degree of rank and estimation the Author of this pamphlet may have obtained, we are not fufficiently informed to pronounce †. Whether he be the first in point of popularity or not, he has a claim on the national gratitude, as first in the order of time; having appeared in print before the letters figned Guatimozin, and other popular publications, forced themselves into notice. We lament the mistake which has fo long poftponed our account of his performance. + We have heard this publication afcribed to Ch―s F Sh-d-n, Efq. ART. VII. Experiments and Obfervations made with the View of improving the Art of compofing and applying calcarecus Cements, and of preparing Quicklime: Theory of thefe Arts; and Specification of the Authors cheap and durable Cement for building, &c. By Bry. Higgins, M. D. 8vo. 5 s. unbound. Cadell. 1780. HE Author of this performance availing himself of the earths, and their change into quicklime in the process of calcination, by Dr. Black, and thofe who have fucceeded him in this inquiry, was led to apply thefe difcoveries to the useful purpofe of improving the mortar ufed in our buildings; on the goodness of which their ftrength and durability chiefly depend: a matter, as he obferves, of great importance, in this country particularly; where the weather is fo variable and trying, and the mortar commonly used is fo bad, that the timbers of houfes laft longer than the walls; unless the mouldering cement be frequently replaced by pointing.' Seeing however, the Author adds, that many years are requifite for the greateft degree of induration, which cementitious mixtures like mortar can acquire, or for our discovering the imperfections of them; and that the life of man is too fhort to allow any confiderable improvements of them to be derived from fuch experiments as had hitherto been made; I refolved in the beginning of the year 1775 to investigate more closely than I had hitherto done, the principles on which the induration and ftrength of calcareous cements depend; not doubting that this would lead me by an untried path to recover or to excel the Roman Roman cement, which in aqueducts and the most exposed ftructures has withstood every trial of fifteen hundred or two thousand years.' Dr. Higgins accordingly first made feveral experiments, with a view to ascertain the changes which lime-ftones or calcareous earths undergo in the feveral stages of calcination; particularly with respect to the effential part of that procefs-the expulfion of the fixed air combined with them; the prefence or absence of which conftitutes the principal difference between lime-ftone or chalk and quick-lime. Among many other obfervations deduced from thefe experiments, we learn that lime-ftone or chalk expofed only to a red heat, how long foever continued, ftill retains fo large a portion of its fixed air *, (or ‘acidulous gas,' as the Author denominates it) as to effervefce ftrongly with acids; and to lose no more than one-fourth of its original weight; and that, in this ftate, it flakes flowly and partially, and with little heat:-and that expofed to a heat barely fufficient to melt copper, it loses about one-third of its weight in twelve hours, and very little more in any longer time; that this lime effervefces but flightly in acids, heats much fooner and more ftrongly than the foregoing, when water is fprinkled on it, and flakes more equably, and to a whiter powder. In a variety of trials, this lime appeared to be in the fame ftate with the best pieces of lime, prepared in the common lime-kilns.' From fucceeding experiments we learn further, that a white heat, fufficient to melt fteel, preceded by a long continued red beat, is requifite to expel all the fixed air from pure lime-ftone and calcareous earths; fo as to render them perfectly non-effervefcent, and to give them the properties of flaking inftantly on the addition of water, growing hiffing hot, and falling into a fine white powder. In the procefs thus conducted, 48 ounces of lime-stone, after the total expulfion of its fixed air, lofes 21 ounces of its weight. The Author next fhews, that the perfection of lime, prepared for the purpose of making mortar, confifts chiefly in its being totally deprived of its fixed air. He afcertained the truth of this propofition, by making feveral parcels of mortar with Jime which had been more or lefs ftrongly calcined; and had accordingly retained a lefs or greater quantity of its fixed air. He fpread each fpecimen, as foon as it was made, to the thicknefs of half an inch, on a plain tile previously foaked in water; and exposed them equally in an open place to the influence of the fun and rain. Comparing them at the end of fourteen or For reasons that we have formerly affigned, we chufe to retain the old term, till custom has given a complete fanction to a better. fifteen fifteen months, he found that the mortar made with well burned non effervefcent lime hardened fooner, and to a much greater degree, than that made with common lime, or with the lime above mentioned, prepared by the Author in a heat barely fufficient to melt copper. But the fpecimens made with the lime which had been leaft burned, were incomparably worse than any of the others :- for they never acquired any confiderable hardnefs, and they mouldered in the winter; the fooner as they contained more of the lime, and cracked more in drying.' Confidering that the heat, which he found neceffary to expel the laft portions of fixed air from lime-ftone, was much greater than that usually employed in making lime in this country; Dr. Higgins fufpected that the lime commonly ufed in building is feldom or never fufficiently burned: and on examining feverai fpecimens of fuch lime, he found this fufpicion to be juft; for they all effervefced, and yielded more or lefs fixed air, on the addition of an acid, and flaked flowly, in comparison with well burned lime. The Author next relates fome experiments, which fhew how very quickly lime imbibes fixed air from the atmosphere; on its expofure,to which, it by degrees foon lofes thofe characters which chiefly diftinguish it from mere lime-ftone or powdered chalk; by foon attracting from thence that very principle, to the abfence of which it owes its ufeful quality as a cement, and which had before been expelled from it in the burning. As this obfervation is of the utmost importance, the experiments on which it is founded deferve particular attention. Two pounds, avoirdupois, of the beft non-effervefcent lime, confifting of pieces of the fize of a walnut, expofed on a board, in a paffage open to the air, acquired, in two days, an additional weight of fix ounces and one drachm. In fix days, the lime had increased in weight above twelve ounces: and, in three weeks, it had abforbed a quantity of fixed air, equal in weight to one pound two ounces, one drachm and a half. A fmall allowance, indeed, or deduction, is to be made from this quantity, on account of moisture abforbed, at the fame time, from the atmofphere. This however, according to the experiments made by the Author to afcertain this matter, amounts to fo fmall a proportion as only one-twenty-fourth of the acquired weight. An obvious practical inference is deducible from thefe obfervations that as lime owes its excellence to the expulfion of fixed air from it in the burning, it fhould be used as foon as poffible after it is made, and guarded from expofure to the air, as much as poffible, before it is ufed as by fuch expofure it muft become more unfit for mortar every hour that it is kept, either in a heap, or in cafks pervious to air. In short, it must more or less refemble lime which had been imperfectly burned, and |