IS-15.] 



THE CIVIL ENGINEER AND ARCHlTECrS JOURNAL. 



251 



A great mass of error exists witli reference to the statements of the 

 older writers on this sul ject, as W( 11 as that fur arehitectiiral pur- 

 poses. Arminiiii, for instance, tells ns about boiling; now if absolute 

 boiling evr were praclisid in his day it could only have been the 

 boiling of pigin'-ntal linie, then the only white' permitted, and here 

 any English manufacturer of whiting would laugh him tb scorn. I am 

 •atisfied however, boiling of another kind wan practised from the 

 enjliest agrs,— and continues to be practised to this day by cunning 

 plasterers whenever the stock of putty is exhausted and a supply re- 

 quired rapidly,— that is, the throwing lime into water and— often witli 

 fine sand— covering it down with sacks and thus boiling the mixture 

 per se. 



In my earliest experiments, after being applied to by the Secretary 

 of the Uoyal Commission on the Fine Arts, I saw the obvious neces- 

 sity for a caustic ai,d not an ameliorated lime, and prepared a small 

 frame to show that fierce Dorking lime, properly treated, although a 

 better stucco, was even less destructive to pigments ihan lime buriid 

 l^ehind the Houses of Parliament and deteriorated by two years keep- 

 ing. I then prepared a larger frame, of a practical character fur 

 )>aiiiting on, with such Dorking lime only fuur days old ; and this 

 frame remained heautiluUy perfect more than nine months at Gwydyr 

 House, and is still in existence without a blemish, and in lieu of 

 cracking and crumbling into dust is harder in texture than any stucco 

 or intonaco in the metropolis; but, unfortunately, Her Majesty's Com- 

 missioners, who very naturally were perjjlexed amid the conflict of 

 opinions, instead of submitting such proof to two plasterers and a 

 iwinter, as to its practical nature, submitted it, as to its mere theory, to 

 three theoretic men, neither of whom knew- one iota about intonacos, 

 or pigments, or fresco, or oil, neither of whom ever once examined 

 the practical frame then in the room, ami one of whom had actually 

 declared in their previous report,^ " He knew nothing of the suljtct, his 

 attention never having been called to it," and for fear any nn;n should 

 doubt his word, on the score of modesty, fullowcd up the assertion by 

 a string of ludicrous suggestiims before alluded to, viz., the making and 

 mixing artijicial pTecipitatid carbonalii with intonaco limes. Ulti- 

 mately these referees, after making certain trifling theoretic experi- 

 ments, such as "stirring brushes about equally" (mark the word, as 

 if for an apothecary's potion), for seventeen days without any eflect, 

 received their fees and damned the plan neither of them compre- 

 hended for one moment, nay nut even in its theory, for along ranjbling 

 report denii d many assertions I never made and touched not one 1 did 

 make. Such is the invariable result of references to mere theorists, 

 because of a misumlerstood locus standi : surely the public eye will 

 be opened ere long. The schoolm asier, as I have before said, may 

 teacli the elements of navigation — he may lecture upon it, he may 

 make a book upon it, and any silly fellow can compile a volume, nay 

 he may be a highly gifted ma[i and justly obtain this locus standi — but 

 who would be governed by his judgment on an experienced seaman's 

 practical work at the helm, or ask him to steer a ship? 



This is no vituperation ; i have not any interest atstake,and never 

 had, save the waste of time and pelf to remove error and serve the 

 cause of man. 



The report alluded to states, that "brushes thus diligently stirred 

 about in lime and water for seventeen days were not acted on at all by 

 lime." I ailmire the naivete and genuine innocence of some very ele- 

 vated men (I). Painters in fresco do not stir brushes about in lime 

 and water equally, but use them unequally on a drying and nearly set 

 intonaco, from which is oozing a fierce water of lime aided by an 

 abrasive surface, and of brushes so destroyed all history tells ; Corne- 

 lius gave evidence, and living painters in the metropolis could su))ply 

 dozens, — while every bricklayer by his shoes, every tanner's pitman 

 by his hiiles, every perfumer by his depilatoiy mixtures, amply tes- 

 tifles the fact. 



The same Report states that "Hydrogen (streams of which I pass 

 through rov caustic lime when slaked, and before washing,) has no 

 action on lime." This is good : Fuurcroy, whose experiments I had 

 a practical occ.ision to rept- at twenty years ago, told ns this tweuly- 

 6ve years before that; and I therefore had never dreamed of asserting 

 either that hydrogen acted on lime or lime on hydrogen; but 1 did 

 as.sert, and do now repeat the assertion, that bv passing it through 

 such recent hydrate of lime, in the state of cream, we are enabled to 

 wash off'— especially if hot instead of cold waters be used, (lime being 

 hss while the salts existing in it attt r slaking are more soluble there- 

 in) — all those noxious elements which infinitely more affect pigments 

 and brushes than the mere alkaline causticity of lime ; and, 1 repeat, 

 that in slaking lime something more occurs than the mere solidifica- 

 tion of water as a hydrate. 1 assert that some water is decomposed, 



« Now we have artiGciat carbonate of baryt«l, laliiillely ' uioie beauUlul* and requiring 

 0ttly pure water to ensure its [)■ nuancnt'e. 

 ft L>r. Iteld, as befure itateU in Note i. 



some oxygen combined with the lime as a peroxide, and hydrogen 

 set free along with the heat of fluiility. Uy such passing of streams 

 of hydrogen through it we are enabled therefore to destroy this noxious 

 agency, and gain a purer, better, and more cohesive, plastic and yet 

 caustic hydrate for immi'diate use. 



The Report further asserts that "Fine plasters improve in texture 

 by keeping, merely from a separation and comminalion of particles!" 

 Now every plasterer's man knovis that by keeping, they which were 

 loose, sandy, incoherent, become close, waxy, tenacious and plastic, — 

 how, therefore, the obvious exertion of attraction can be a specimen 

 of r. 'pulsion 1 leave the theoretic LU.D.'s to illustrate. 



Again, if nothing more than a mere and almost mechanical hydrate 

 be formed by slaking, I should be glad to be (not theoretically— no, no 

 — 1 mean practically,) enlightened as to how it comes that in all the 

 fiercer limes— Dorking, Bath, or blue lias— after rapid slaking, sul- 

 (iliur becomes oxygenized, sulphuric acid fornnd, and sulpliat''s of 

 lime, magnesia, &c., ooze from every joint of brickwork in less than a 

 month. 



Again, how is it after passing hydrogen through them in the creamy 

 state, and washing them, no such oxygeuizement takes place and no 

 salts form ? 



Again, how is it that in the tanner's pit the skin is swelled and 

 gelatinized, and the hair and epidermis are acted on, and then sud- 

 di'iily— although the lime, under a water vairt, is quite caustic— such 

 power is lost, ami fresh lime must be used to procure these effects 

 before the skin is destroyed ? 



1 assume no wire-drawn degree of knowledge ; I look with contempt 

 on the gingerbread of science and mere jargon of a sesquicarbonited 

 nomenclature ; but I am not to be put down in plain, practical matters 

 to which 1 have devoted years : and a mere assumption, on parchment 

 brains, I so much detest 1 treat my oivn degres as waste paper. 



On other matters intended to be developed by the frame alluded 

 to, and I humbly opine perfectly demonstrated therein, such as the 

 defects and absurdities of all ordinary plaster-keying, and the ines- 

 timable worth of native carbonate of barytes as proposed by me thirty 

 years ago, I must dwell more at large in ray next paper, which more 

 properly may claim them as appertaining to architecture. 



With reference to hydrofuges, on which much research has been 

 displayed, and more time thrown away, I merely say — hydrofuges to 

 walls are strictly empirical applications, and advisable only wh.-n old 

 and defective walls are to be painted on, and they produce, in the 

 nature of things, bad effects on the walls themselves. Good strong 

 lime, well washed coarse sand, tolerably pure water, with that addition 

 which was proposed by me and referred to Mr. Barry, would have 

 secured to his cement, ere this, a greater hardness than that of the 

 bricks and a perfect freedom from circulatory damp, an 1, I may add, 

 afforded a cement more worthy of his splendid foundation. 



There is a gross error, retailed from Pallomino, with reference to 

 salts, viz., " that if the rough cast be not dry saltpetre will form." 

 The rough cast ought never to be dry ; and saltpetre, that is nitrate 

 of potas, never can, while the salt he means — nitrate of lime — rarely 

 mill be formed, and then only when the elements had existed, H priori, 

 in the sand, water, or hydrate of lime. The same applies also to a 

 Mr. Smith's advice to the Commissioners, (2Dd Report, page 53,) 

 " 7wl to permit the workmen to urinate in the chimney corners ;" the 

 writer being, apparently, unacquainted with the fact that the preparers 

 of nitre, in artificial beds, in despite of great quantities of urii;e, never 

 form nitrate of potas but this nitrate of lime. 



W. Harris Dinsdalb. 

 July 8, 1815. 



SECOND REPORT OF COMMISSIONERS OF INQUIRY INTO THE 

 STATE OF LARGE TOWNS AND POPULOUS DISTRICTS. 

 The following is an abstract from part of a most important and 

 elaborate report presented to the House of Commons. From the extent 

 of the document (it consists of two large folio volumes), we can present 

 but a small part of its contents notwithstanding their interest, but we 

 hope to recur to the subject. 



In pursuance of the terms of your Majesty's Commission, whereby we are 

 enjoined to report to your Miijesty, from tim« to time, our proceedings, we, 

 the undersigned Commissioners, do now humbly present this our further Re- 

 port. We stated in our First Report the course which we considered it our 

 duty to pursue in prosecution of our inquiry, to which we appended the evi- 

 dence we had then received, and also an alistract of the replies then given 

 from fifty towns visited, showing their conditioa in respect to drainage, 

 cleaubing, and the supply of nater. 



33* 



