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V '* 
 
 S GlU E 
 
 OBSERVATIONS 
 
 ON 
 
 THAT DISTEMPER IN TIMBER 
 
 CALLED 
 
 THE DRY ROT. 
 
 Q. 
 
 Cy 
 
 ' m 
 
 LONDON: • • 
 
 PRINTED FOR J. JOHNSON,' NO. 72, ST. PAUL’s 
 CHURCH-YARD. 
 
 1795 - 
 
OBSERVATIONS, &c. 
 
 Some years ago having unadvifedly 
 purchafed a houfe in which there was 
 much decayed timber, and afterwards 
 finding this was juftly attributed to what 
 is called the dry rot^ I have had fufficient 
 reafons for attending to that diftemper. 
 When I firft faw the mifchief done, I 
 was fo entirely ignorant, that I had no 
 other apprehenfions, than fuch as ai'ofe 
 from a calculation of the. immediate ex- 
 pence of repairing it; but have fince 
 found that to have been a fmall part of 
 the confideratioh. Though the follow- 
 ing remarks convey a very imperfe6t 
 idea of a fubjedl hitherto much negle£l:- 
 ed, I hope they may be the means of 
 inciting better informed men to confider 
 
 A 2 it; 
 
( 4 ) 
 
 it ; and if any method of preventing or 
 curing the diftemper fhould be difco- 
 vered, great inconveniences and heavy 
 expences would be faved to the owners 
 or inhabitants of fuch houfes. Much fa- 
 tisfailion would alfo refult to my own 
 mind, if, by my error, others may be 
 refcued from fuch detriment. 
 
 In Leviticus, chap. xiv. there is an ac- 
 count of the leprofy of a houfe, which 
 feems to have been the dry rot, and I 
 muft beg leave to take' notice of the paf- 
 fage. It is there defcribed as “ a plague 
 in the walls of the houfe, with hollow 
 ftrakes, greenifli or reddifh, which in 
 light are lower than the ground.” The 
 means diredted for its cure are, to take 
 away all the diftempered parts, by rer 
 moving the ftones affedled, and fcraping 
 
 * When thefe Hieets were ready for the prefs, I was in- 
 formed that the Society of Arts had offered premiums for the 
 difcoycry of a method of preyenting and curing the dry roty 
 and that fome obfervations on that.fubjedl had been pub- 
 iiihed hi their Tranfadioiis. 
 
 the 
 
( 5 ) 
 
 the walls within and without, carrying 
 the corrupted materials to a place with- 
 out the city. If after a certain time the 
 diftemper was found to return, it was 
 called a fpreading leprofy ; ,the prieft was 
 enjoined to deftroy the houfe, and the 
 materials with which it had been built, 
 were never to be itfed again for the fame 
 purpofe. 
 
 I fliall not make any obfervations on the 
 devotional part of the ceremony, but it ap- 
 pears that the Jews fufpedled the diftem- 
 *per to originate from the ground, though 
 they only removed the infedled parts; 
 that ntnning water was ufed in the ce- 
 remony; that the old materials of fuch 
 houfes were never ufed again ; and that 
 fuch houfes were confidered as unhealthy 
 and dangerous to the inhabitants; but 
 for the laft opinion, as far as I know or 
 have feen, there is no foundation. 
 
 Had I time to confult a variety of au- 
 
 A3 
 
 thors, 
 
 
 
 / 
 
( 6 ) 
 
 thors, I might probably find many other 
 remarks relating to this fubjeit. But in 
 truth, what I have to fay will he chiefiy 
 compofed of fuch obfervations or con- 
 jedlures as have occurred to me from 
 feeing the ftate and progrefs of the dif- 
 temper in my own houfe, of which I 
 may he allowed to fpeak plainly, or of 
 fuch as I have colle61;ed by inquiry, or 
 in converfation ; and there is much rea- 
 fon to fufpedl that the care generally 
 taken to conceal the knowledge of the 
 diftemper, when it exifted in ' a houfe, 
 has been one of the principal caufes why 
 we do not at prefent know more of the 
 dry rot. I find alfo, that the little which 
 is known on this fubje(5l by artificers, is 
 often concealed by them with much af- 
 fedlation of importance. 
 
 Perhaps the beft method of acquiring 
 any accurate knowledge of this diftemper 
 would be, 
 
 Firft, 
 
( 7 ) 
 
 Firft, to ftudy the general nature of 
 the foil in which houfes affeited with 
 the dry rot are built. 
 
 Secondly, the accidental or adventitious 
 caufes of the dry rot. 
 
 Thirdly, the effedt of the dry rot on 
 different kinds of Jlone^ and other hard 
 materials ufed in building. 
 
 Fourthly, the effedl of the dry rot on 
 timber, and the kinds of timber moft 
 readily affedted by it. 
 
 To thefe might be added, mifcellaneous 
 obfervations, containing an account of 
 the peculiar effedts of the dry rot in cer- 
 tain lituations,; and of the means ufed, 
 with or without fuccefs, for preventing, 
 or curing timber affedled with, the dif- 
 temper. , It is not without the greateft 
 diffidence that I mention this arrange- 
 ment, from a confcioufnefs of the very 
 imperfedl manner in v/hich I have been 
 able to execute -ray own defign; -but 
 
 A 4 many 
 
( 8 ) 
 
 many allowances will be made for the 
 firft elTay on any fnbjedl:. 
 
 My houfe is fituated on the north fide 
 of Sunbury common, which, though a flat, 
 is called a hill^ I fuppofe, as lucus a non 
 lucendo, but it is fo named in Speed's map 
 of the county. During the winter, if 
 there happens to be much rain, a confi- 
 derable part of the common is covered 
 with water, not only in the pits which 
 have been occafionally made, but from 
 the mere level of the common ; and in 
 times paft it is not unlikely btit a great 
 part of it may have been overflowed by 
 the Thames^ which is not far diftant. 
 The floods in the year 1774, the 
 
 laft winter, rofe enormoufly high, and 
 though, ftridlly fpeaking, they did not 
 reach the common, from the amendment 
 of the channel of the river by its navi- 
 gation, and by the banks being raifed 
 where the nature of the ground would 
 
 allow 
 
( 9 ) 
 
 allow of it, they made great devaftation 
 
 in many of the neighbouring parts. But 
 
 the conftitution of the foil is fuch, that 
 
 the water is foon drained through the 
 
 gravel, fo that the common, except in 
 
 particular fpots, is not fwampy, nor ruftiy, 
 
 nor mofly, but covered with heath and 
 
 gorfe, or a fine turf, as is the cafe in almoft 
 
 all healthy, but uncultivated land. The 
 
 common, though fomewhat lower and 
 
 flatter, is not unlike that of the vaft tra£l 
 
 of land, Houn/low heath. Scarcely any trees 
 
 / 
 
 grow upon the common, but in the ap- 
 propriated parts there is no difficulty in 
 raifing them. At Littleton, the highly 
 refpedled owner, now in the eighty-fe- 
 venth year of his age, has had the fatif- 
 fadlion of planting and feeing many a 
 fine tree flouriffi; and at Kempton, the 
 laft refidence of the famous Sir John 
 Chardin, which adjoins, and is nearly on 
 a level with the common, there is an 
 abundance of very fine trees, oaks, elms, 
 
 beeches, 
 
( lo ) 
 
 beeches, walniits, See. ; which have not 
 only arrived at their full growth, but are 
 many of them of a century’s ftanding. 
 One of my neighbours alTured me, that 
 fome cupmofs oaks which he planted on 
 the common two years ago, have in that 
 time fhot more than feven feet. I there- 
 fore conclude that the principle of vege- 
 tation is generally vigorous and healthy 
 over the common, though elms feem to 
 be the favourites of the foil, and it has 
 been faid that none of the tribe of firs ac- 
 quire their full growth or beauty, and 
 that they do not endure their accuftomed 
 time. There is nothing apparent in the 
 nature of the foil which fhould render 
 houfes built upon it fubjedl to the tfrj rot, 
 though patches of it may be altered or 
 corrupted by the long lodgment of water 
 upon them, or by being made conftantly 
 damp from imperfecftly erupted fprings. 
 It is reafonable to believe if a houfe be 
 built on ground ever fo pure, but was in 
 4 its 
 
( II ) 
 
 its fite to include one patch that was de- 
 praved, the dry rot might he produced 
 in one part of the houfe, though '^every 
 other part were perfe6lly healthy. 
 
 The houfe I purchafed has been built 
 upwards of fifty years, but for the laft 
 twenty-five, though always inhabited, 
 had been grievoufly negledfed. When I 
 took polTeflion of it, -there was a great 
 quantity of rotten timber in various parts 
 of it. When the roof was taken off, the 
 plates and breflumers were found decay- 
 ed ; when the wainfcot was removed, the 
 ends of the beams were in the fame 
 Hate ; and the farther we proceeded, the 
 more difcouraging every thing appeared. 
 I now believe it would have been wife to 
 have taken out the whole infide of the 
 houfe, though it was then judged better to 
 repair. By time and perfeverance all the 
 difficulties were overcome, and when the 
 houfe was made habitable, I had time to 
 review what \vas pall, and the mortifying 
 
 opportunity 
 
( 12 ) 
 
 opportuility of obferving the future pro- 
 grefs of a diftemper, the effedls of which 
 had for the prefent been removed^ but 
 which foon fliewed a difpolition to return. 
 
 Care was, however, taken in repairing 
 to ufe as little wood as poflible in thofe 
 parts which had moft fuffered before. 
 The entrance, inftead of being wainfcot- 
 ^ ted, was ftpccoed (but abfurdly enough, 
 X a fkirting-bpard was added), and where- 
 ° ver it was neceflary to fet uprights^ the 
 floor was paved with llone as a fecurity. 
 One fmall room which was very much 
 affedted, after taking up a part of the 
 floor, and ftripping off the lining, I have 
 yet fuffered to remain in the fame ftate, 
 from a perfuafion that the diftemper 
 would be reproduced if it were immedi- 
 ately repaired. 
 
 There has fince been no token of the 
 rot in any of the upper parts of the 
 houfe, but the entrance, which is paved 
 with Portland ftone, and which is con- 
 7 ftantly 
 
V 
 
 ( 13 ) 
 
 ftantly expofed to a current of open air 
 in different directions, the doorpofls of 
 an inner door, dividing the fore from 
 the back entrance into the houfe, are 
 entirely decayed, with fome part of the 
 Ikirting boards, though other parts are 
 perfectly found; the decayed and the 
 found not being many feet afunder. On 
 thofe parts of the floor where the wood 
 which Hands upon it is decayed, the 
 Hones are perpetually damp in every kind 
 of weather, and the wood univerfally 
 began to decay at that part neareH the 
 ground. From thefe premifes, fupport- 
 ed by other obfervations, I have ventured 
 to draw thefe conclufions. i. That the 
 caufe of the rot in timber ^ derive d from 
 the g round . 2. That the ground which 
 produces this diHemper is always damp. 
 3. That the Hone moH commonly ufed 
 for paving floors does not intercept the 
 caufe of the rot. 
 
 
 
 / 
 
 What 
 
 2. 
 
 
 

 C 14 ) 
 
 
 \ 
 
 “jf, . 
 / 
 
 % 
 
 7 
 
 
 • What chymical alterations .may have 
 taken place between healthy and diftem- 
 pered ground, before this becomes capa- 
 ble of - producing the rof, I cannot tell, 
 though in a full inveftigation of the fub- 
 jecSl it would be neceffary to inquire. 
 rThe mechanical efFe£f of thefe is per- 
 ypetual darapnefs, and the rotted earth 
 / found in finks and fuch places gives me 
 a notion of it. This earth I prefumc, is 
 become, by the changes it has under- 
 gone, from fome principle perhaps ana- 
 logous to fermentation, deprived of its 
 j natural powers of vegetation, which it 
 might recover by being expofed to the 
 air, or by admixture with other bodies. 
 For the prefent fuch earth has acquired 
 the property of producing the rof, which, 
 
 , as far as I know, may be a perverted 
 ■ ] vegetation, and till we have difcovered a 
 method of altering its prefent qualities 
 or correcting its influence, the only ef- 
 fectual remedy for preventing the rot 
 
 will 
 

 ( 15 ) 
 
 /will be, to remove fuch dijlempered ground, ^ 
 
 ' When this ground is removed, and drains 
 made if thought needful, the vacuity 
 ihould be filled up with fome healthy 
 fubltance not fufceptible of the diftem- ^ 
 
 per, fuch as broken glafs, clean pebbles, ^ 
 a portion of unflaked lime, the refufe^"^ 
 of vitriol works, and the like ; but ^ 
 we Ihould remove all the difcoloured 
 ground, and not fatisfy ourfelves with a 
 layer or thin coat of thefe fubftances. 
 
 . Perhaps the nature of this diftempered 
 ground may fometime be difcovered by 
 knowing what it is hot. I found a 
 wooden Arable on my premifes, built in 
 the ufual manner, with a frame, an out- 
 fide covering of deal boards feather- 
 edged, and a lining of flat unpainted 
 boards. This had flood more than fifty 
 years, and when it was taken down, 
 though the timbers were wormeaten 
 and decayed, there was no token of the 
 rot throughout the building. Frames 
 
 of 
 
f, 
 
 ( i6 ) 
 
 
 4 of cucumber and melon beds, though in 
 conftant ufe, and ftanding on a fubftance 
 that might be fufpeiled as likely enough 
 produce the ?'ot, will endure for many 
 years, and at laft perifli, without any to- 
 kens of this dilfemper; one might there- 
 ^^^‘^‘^fore conjecture that animal fubftances of 
 this kind do not generate the rot. 
 
 Objections may be made to the opinion 
 of the rot proceeding univerfally from the 
 ground, becaufe it has been difcovered 
 in parts of houfes which had no direCt 
 communication wdth the ground, the in- 
 termediate timber being clear, as in gar- 
 rets and particular parts of houfes. At 
 the firfl: view this fliould have originated 
 in the timber itfelf, or in fome fubftance 
 w'ith which that was in contaCt or had a 
 direct communication. This happened 
 in the houfe of one of my friends, who 
 
 
 
 /^T*~ is a very competent judge of the faCt. 
 He one day obferved a fingle pannel 
 wdiich was cracked, on the wall ftde of 
 
 his 
 
( 17 ) 
 
 his drawing-room, exhibiting tokens of 
 the rot, though every other part of the 
 houfe was clear of the diftemper. On 
 removing this pannel he found a large 
 cake of the fungous w’eb, which accom- 
 panies the rot, filling the fpace betw^een 
 the pannel and the wall ; but tracing 
 this, he was led to the water-pipe, which 
 fonie time before having been choaked, 
 the water had regurgitated over the cif- 
 tern of the pipe, and fiow'ed on the out- 
 fide of the wall to the ground. This 
 had continued fo long, or been repeated 
 fo often, that oppofite to the injured 
 pannel it had waflied out the mortar, and 
 foaked through the wall itfelf, till the 
 oppofed pannel became affedled with the 
 rot. This brings us back to diftempered 
 ground, and a moment’s confideration 
 will llievv how' readily this may happen 
 in garrets, in which the foaking of w-ater 
 is difregardcd if it does not defcend to 
 the principal rooms. It will not ho\v- 
 
 B ever 
 
cvcx be hence fuppofed that all moift 
 ground is capable or difpofed to produce 
 the ;'o/, but gr oun d fo corrupted by con- 
 I ti nned ftagna t ing moifture, as to become 
 ' tl eprived of ^ n atur al propertie s, and to 
 have acquped^ perverted princip le of 
 vegetation ; or a power of giving to 
 j w'ood fuch a property as fliall generate 
 I the procefs by which the rot is produced. 
 On inquiry it wdll probably be found 
 that there is a great difference bet-ween 
 the moifture given to Avood by ftagnat- 
 ing or running water, and betw'een fim- 
 ! pie moifture, and moifture mixed with 
 corrupted fubftances. It is alfo to be re- 
 membered, though the w'ood neareft the 
 ground firft begins to decay, that the in- 
 fection will foon fpread to.a.diftant and 
 healthy part, if there be a medium of 
 communication by w hich it can be con- 
 I vcycd. 
 
 In, every n'egledted or uninhabited 
 houfc, if the pipes be choaked and over- 
 flow, 
 
( I9 ) 
 
 flow, the water riitming between the! 
 Wall and the w'ainfcot may efcape to the 
 ground, and if it has a proper drain, do 
 no mifchief. But if there be a repetition 
 of thefe overflowings, fo that any piece 
 of timber becomes foaked in' the pailage 
 of this water mixed with the fweepings 
 of the roof, in a place liot expofed to the 
 air; or if the water fhould reft after- 
 wards on a fpot of ground with which 
 timber comes into contaft, the rot may 
 begin in this one pait, and then fpread 
 its devaftation around. Thus the foun- 
 dation of a general rot in the timber of 
 a houfe may be laid by negle6ting its 
 fir ft appearance. But this kind of rot 
 admits of a certain cure if it be under- ' 
 taken in a proper time, and the method 
 effecftually completed. Yet the firft ex- 
 pence is fometimes fo great that people 
 are willing to leffen or evade it, if they 
 can find any plaufible reafon to fatisfy 
 their minds. But this is very bad huf- 
 B 2 bandry. 
 
•• ( 20 ) 
 
 bandry. There is a handfome 
 
 houfe'in one of the itrccts leading to 
 .Grojvenor Square^ wlrich was fo greatly 
 and repeatedly infcfted with the rot, that 
 ,the owner fold it, for this reafon alone, 
 far below its real value. It was then pur- 
 chafed by a nobleman who underliood 
 more of the diftemper, or ufed more ef- 
 fedtual means for curing it, which fuc- 
 ceeded, as I am informed it is now free, 
 the nobleman at the prefent time living 
 in it, and it is fuppofed to be w^orth 
 three times the fum it coll him. I pre- 
 fume that the rot in this houfe was 
 merely caufed by the overflowing, of the 
 pipes, wdiich might at length have pro- 
 duced the diftemper, perhaps fome years 
 after the circumflance was forgotten, no 
 , other houfes in that flreet having the 
 rot. It flaould be remiarked, though I 
 t do not know that it is of much confe- 
 [quence, that the rot ascends from the 
 
 ■pa It 
 
( 21 ) 
 
 part where it was formed, and does not i 
 defcend or fpread much laterally. 
 
 In fome houfes the rot has been attri- 
 buted to air corrupted, or acquiring chy- 
 mical properties deltru(Stive' to timber, I, 
 
 .... \ 
 
 i 
 
 from its mere confinement, without the 
 mixture of any other fubftance, or any 
 
 
 exhalation from the ground. If com~y^^^ ^ ^ 
 
 mon air by confinement alone acquired 
 the ■ property of producing the rc/, cer- 
 tainly very few houfes could be free 
 from it, becaufe there is in every one 
 fome place or other of this defcript-ion. 
 
 But this opinion is very much to be 
 doubted,-and it is probable the miftake 
 Inight arife from the timber having gone 
 through the firft part of its procefs with- 
 out notice, till the rvood, by cracking or 
 being in a mouldering ftate, drew atten- 
 tion. But when the genuine caufe of the j' 
 7'ot exiftsjthe progrefs will be more rapid 
 in a confined than an open place ; though 
 my door polls, expofed to the open air 
 
 B 3 in 
 
 ( 
 
^ ( 2 ? ) 
 
 ! in twQ dire£lions, have decayed in about 
 i three years, and they are not fixed in the 
 , ground,' but on a ftone pavernent. 
 
 ^ There is ufually no area round houfes 
 built in the country, or rather, many are 
 built without one. In certain fituations, 
 
 / if the ground be rnuch higher at the 
 back than the front of the houfe, the 
 difadvantage is foon evident from the 
 dampnefs and difcoloration of the wall, 
 efpecially if it be covered with ftucco or 
 , plaifter, whether or not the dry rot flioukl 
 be produced, as w^ell as in the general 
 look of the houfe, Avhich is apt to become 
 . ifraked with green, and rnolTy. It is 
 certainly beft, on many accounts, to have 
 an area, if pofllble, to all houfes; for, 
 though healthy earth lying againrt the 
 w^alls of a houfe, w ill not, I apprehend, 
 ' ^ produce the rot, much is to be appre- 
 hended from tainted or diftempered 
 earth. I advifed a gentleman in Wor- 
 (ejlerpplre, who applied for my opinion 
 
 ou 
 
( 23 ) 
 
 oil account of the unhealthinefs of 
 the cottagers in his neighbourhood, to 
 
 have a trench or drain round ' every cot- 
 
 ) 
 
 tage, that no more water might lodge 
 than fell within the fite, and to have back 
 as well as front w’indows for the purpofe 
 of ventilating them. For this purpofe it 
 is alfo much better, and not more expem 
 live, to have Aiding windows or faflies. 
 But this is a digreffion, though on a 
 fubje£l which has very much engaged 
 the attention of a lady diftinguifhed by 
 her genius and her humanity. 
 
 If the part of a houfe affeiled with the 
 rot be near the outer wall, probably a 
 fough or drain would be of much fer- 
 vice, and the wall might, without da- 
 mage, be perforated, and then the caufe 
 of the damp would be more elfedtually 
 removed. 
 
 Stone often becomes alfeited with this ' 
 dilfemper, of w hich I had for a long time 
 110 fufpicion, and, as was before obferved, 
 
 B 4 the 
 
 
 
 
( H ) 
 
 the fofter kinds do not intercept the caufe 
 as it rifes from the gronnd. There are 
 _ various kinds of ftone ufed for pave- 
 ments, the moft common of which is the 
 Portland', next to this is the Pnrbeck, 
 taken from tjie fame quarry, but of a 
 harder texture, perhaps becaufe it has 
 been longer formed, or more expofed to 
 the air ; then the YorkJJjire flab, not fo 
 pleafant, but harder than the Purbeck ; 
 and there is likewife in ufe a red ftone 
 cut into fquares or lozenges, brought 
 from Bremen, and a blue ftone of a fimi- 
 lar kind, but fomewhat harder, from 
 Sweden. 
 
 t My entrance is paved w’ith pretty large 
 ' flabs of Portland ftone, which is'con- 
 ftantly damp in that part where the rot 
 has again appeared; and it is fpotted 
 with white blotches not unlike leprous 
 fpots upon the fldn; and by thefe ap- 
 pearances I can with eafe trace the ex- 
 tent and progrefs of the roj. In the faw- 
 
 ing 
 
( 25 ) 
 
 ing of ftone which might be pretty dry 
 when it was fubmitted to the infirument,. 
 fo much water is ufed, and for fo confi- 
 derable a fpace of time, that the Ifone is 
 thoroughly foaked; and it is the cuftom- 
 to lay down the ftone while in this ftate, 
 to which the fame objection may be 
 made as in timber newly worked np, 
 and immediately painted; of the reafons 
 for which \ye fliall. afterward take notice. 
 But the dampnefs of the hones before 
 nbferved, is not occafioned by the moif- 
 ture with which it was imbued before 
 they were laid down; for thoitgh they 
 were all citt at the fame time, and many 
 of the llabs from the fame block, none 
 are now difcoloitred or fiiaded with the | 
 damp, but thofe which are placed where * 
 the rof exifts. It is therefore reafonable * 
 to think that they have not retained their 
 
 f 
 
 original moifture, but that they are her 
 come moift from the peculiar influence 
 of the ground on which they are laid.- 
 
 I think 
 
( 26 ) 
 
 ' I think however that I have feen 
 ftones with flight marks of the kind 
 above mentioned when they were firlf 
 cut, and, thence conjedture that the dif- 
 pofltion to decay may originate in the 
 quarry, from earth iniinuated between 
 the lamina of the ftqne, or from fome 
 other caufe, becoming corrupted. If 
 ftones with thefe marks are laid on 
 healthy ground, or ufed as fteps where 
 they are furrounded by the air and kept 
 dry, the fpots do not, I think, increafe 
 in number or fize. But if fuch ftones 
 were to be laid on diftempered ground, 
 though they might not immediately 
 give rife to the diftemper in other ma- 
 terials, they would be more fufceptible 
 of it, and more readily convey it than 
 if they had been originally healthy. In 
 lioufes built or faced with ftone, 1 have 
 alfo often feen ftones with fuch tokens 
 of imperfetftion, and they are the firft to 
 decay. In that beautiful houfe of Mr. 
 
 Milnps^ 
 
V 
 
 ( 27 ) 
 
 Milnes, in Piccadilly, many of the facing 
 ftones have decayed with fuch marks 
 upon them, and fome of thofe newly 
 put up, have them. Yet it muft be re- 
 membered that the more fpeedy decay 
 of fome ftones may alfo depend upon 
 other caufes, fuch as their being cut or 
 placed in a wrong direftion. 
 
 The Purbeck ftone is of the fame tex- 
 tiire, and has the fame properties, as the 
 Portland, though harder; and it is on 
 this account lefs fufceptible of impref- 
 fi.ons froiu the caufg of the rot. The 
 Torkfhire flab is very hardy, and com- 
 ppfed of different fubftances as well as 
 different in its fexture; of courfe it is 
 fitter for hazardous fituations. The red 
 ftone imbibes the moifture freely, and 
 condu6ls the diftemper, w'hich makes it 
 flake; as does likevvife, I underftand, the 
 blue ftone, though in a lefs degree. 
 Gritftone, which feems to be compofed 
 of diftindt granulations, w^ould probably 
 
 fuit 
 
r 28 ) 
 
 iuit very well, and for paflages, efpe- 
 cially thofe below the ground ; the gra- 
 nite, now commonly ufed for paving the 
 flreets, w'ould make a fufEciently con- 
 venient and durable pavement. But all 
 ftone cafy to cut, either from the foftnefs, 
 of its fubftance, of the fponginefs of its 
 texture, feems improper in every place 
 liable to the rot. 
 
 This diftemper feems to have no effecT 
 upon brick walls or on bricks, provided 
 they are well burnt, and layed with good 
 mortar, farther than from the fimple 
 effedf of moifture; but fo ft bricks, or bad 
 mortar, when operated upon by conftant 
 .damps, have been fuppofed to give a 
 rooting place to it. Though it does not 
 penetrate into the fubftance of a brick 
 w'all, the fungous w'all may often be feen 
 mantling over its furface, yet without 
 hurting it. But if it chance to meet any 
 wood in its pafTage, there it fixes and 
 feems to acquire frelh vigour, if there 
 8 be 
 
( 29 ) • 
 
 be any degree of moifture, but not in 
 abfolutely dry places. As bricks are 
 found not to be alfedled with the rot 
 or its caufe, the obfervation may on va- 
 rious occafions be turned to good ac- 
 count, by faving the ufe of timber, in 
 places where it might be expe<5ted 
 fpeedily to decay. Store rooms of every 
 kind might be more fuitably fitted up, 
 and with fome ornament, with rubbed or 
 glazed bricks of different forms, in the 
 manner of Mr. Cartt^yrigbt's patent ones ; 
 or with tiles of various kinds and colours. 
 The houfe in- the fouth-weft corner of 
 Hanover-fquare is a beautiful example of 
 fine brick work ; and the faflrion of 
 making paper to imitate brick, is a proof 
 that it would not offend. 
 
 Stucco, and plafter of the coarfer kinds, 
 feem to fuffer no injury from the rot^ 
 (notwithftanding the flagrant negligence 
 with which mortar of every kind is 
 mixed) except from fimple moillure. 
 
 W'hen 
 
( 30 ) 
 
 When thefe are laid on walls, there is no 
 occaiion to confider the fubjedl as far as 
 they are concerned, but when, for the 
 purpofe of making plaifter partitions in 
 dangerous places, it is neceflary to fet up 
 ftancheons, or to ufe laths, thefe will foon 
 decay, and then the partitions fail. In- 
 ftead of fuch work, the expence of raif- 
 ing a brick partition in the firft inftance, 
 when we are not fure that the earth is 
 found, will on the whole be the leaft, 
 and the work far moft permanent. 
 
 The injury done to ftone does not, 
 however, render it unfit for the purpofes 
 for which it was defigned, and many 
 years would pafs before it M'^ere adlually 
 fo decayed as to moulder, though it 
 might be blemilhed to the eye. The 
 principal misfortune to a building is 
 when timber is afFedled, becaufe of the^ 
 repeated trouble^ and the expence of re- 
 pairing it. 
 
 I The manner and the time in which 
 I each 
 
I 
 
 ( 31 ) 
 
 each particular kind of timber naturally 
 decays, is now pretty well underftood. 
 The conftituent parts of which it is com- 
 pofed lofe their connexion, but preferve 
 their form, in fuch a manner that each 
 kind, thoitgh wholly decayed, may be 
 diftinguiflred. But in the rot, the very* 
 form or internal ftrudlure is deftroyed, 
 lb as to render them all nearly alike. 
 
 I 
 
 The wood becomes moift, decays, fliri- 
 vels, then cracks and breaks as if it had 
 been parched by lying for a long time 
 near a firong fire, or as if it had been 
 foaked in fome deftrudfive liquor. 
 
 In places affedted with the rot, the 
 wood next the ground will certainly firft 
 decay. Skirting-boards, which are in 
 fadt neither ufeful nor ornamental, and 
 which are always made of flight boards, 
 exhibit their tokens by becoming fpotted 
 or producing the fungus, efpecially at 
 their jundtion with each other ; the 
 mouldings, if there be any, round the 
 
 doors; 
 
( 32 ) 
 
 doors; then the Iteppings of joifts, door, 
 and other pofts, of whatever kind. I 
 alfo obferve if two pieces of wood ai'c 
 joined together, that the diftemper makes 
 a quicker progrefs, by running between 
 the united furfaces, than in one piece of 
 equal dimenfions. The flighteft work is 
 
 i 
 
 always firft affecled. 
 
 Different caufes taken from the timber 
 itfelf have been affigned for this diflem- 
 per. Some have fuppofed that timber 
 cut from trees which grew in certain fi- 
 tuations was peculiarly liable to the rof, 
 thofe which were taken from very moift 
 fituations being judged to have the great- 
 eft propenfity to it ; and the lower parts 
 of Ej/ex have been exprefsly mentioned 
 on this occafion. There may be fome 
 truth in this as a general reafon, becaufe 
 oak, or any other timber, growing in 
 America or Britain, for inftance, may 
 vary in the time of its natural duration. 
 Yet the mifehief ariling from this caufe 
 
 will 
 
( 33 ) 
 
 will be fo flow in its operation as to be 
 hardly perceptible, if it Ihonld even 
 amount to one quarter of its time, unlefs 
 it were employed on fome particular and 
 equal fervice. - No timber of any kind ' 
 has however the pov/er of withflanding 
 the rot\ they, all yield to its influence, 
 fcarcely varying in any other refpedl 
 than the time of enduring its effecfl. 
 
 With regard to the natural duration of 
 timber, I believe it has been proved, that 
 much depends on the time of barking 
 and felling trees ; the time they are kept 
 after they are felled before they are 
 worked up ; the manner of keeping 
 them ; and the time which pafles before 
 they are ufed, when fawed or cut into 
 planks or beams. It has even been af- 
 fcrted, that a moiety of their duration 
 depends on thefe circumftances ; and for 
 thefe reafons, perhaps, mahogany is fo 
 flout and lafting a timber. The age of 
 the tree when felled may alfo be of great 
 
 C importance. 
 
( 34 ) 
 
 importance. But unfortunately it is the 
 cuftom to negleft all thefe points in tim- 
 ber ufed in buildings, efpecially as fo 
 great a number have been raifed within 
 a very few years. Even the moft valu- 
 able oaks have been managed fo that 
 when they are filled, the bark fliall eafily. 
 peel, and be ready for the beft market, 
 with the view of faving the intereft, or 
 of procuring a quick return of money; 
 and trees cut down in one feafon have 
 been, without hefitation, worked up in 
 the enfuing year, making the goodnefs 
 or badnefs of the timber, provided it 
 appeared Avell, a matter of fecondary 
 confideration. For the purpofe of work- 
 ing more eafily, and perhaps of mea- 
 furing better, the fir beams, flored by 
 the timber merchants, are generally kept’ 
 foaked in water till they are fawed and 
 prepared for their fpecific ufes ; and then 
 they are forthwith fixed in buildings, 
 long before the moifture they had ac- 
 quired 
 
V 
 
 ( 35 ) 
 
 quired can be exhaled. Hence may be 
 explained that llirinking of the floors 
 and wainfcotting fo obvious in all the 
 new-built houfes ; though I underhand 
 that all timber, how'ever well preferved, 
 newly worked, has for a certain time a 
 tendency to flirink, in a fmall degree. 
 
 • In fliip-building, in which the greateft 
 poilible care is taken to preferve and 
 work the timber when in its moft per- 
 fe£f . ftate, it is a rule cai'efully to choofe 
 the proper time of barking and felling 
 the oak's, of keeping them till the native 
 moifture be exhaled, of foaking the tim- 
 ber, and again keeping it in a dry place, 
 even within the influence of the fire, for 
 a long time before it is worked, and then, 
 again after the planks and timbers are 
 formed for exprefs purpofes ; and it will 
 fcarcely be believed how great the dif- 
 ference is, between fhips built with thefe 
 precautions and thofe in which they are 
 neglefted. How far fuch obfervations 
 
 C a may 
 
 t 
 
( 36 ) 
 
 may apply to timber ufed in buildings, I 
 cannot tell, though it is reafonable to 
 think that whatever accelerates the na- 
 tural decay, may difpofe to the rot, or at 
 lead; render it a more fpcedy vidrim in 
 infedled places; fo that fome attention 
 ought to be paid to thefe matters, with 
 timber intended for buildings. 
 
 The propenfity in timber to be infedled 
 
 with the rot, and its fpeedy decay when 
 
 / 
 
 alfefted, certainly very much depend 
 alfo on the loofenefs or clofenefs of its 
 texture, and for this reafon fir is the lead: 
 eligible, though of late it is almoll: the 
 only kind ufed in buildings ; and it would 
 be difficult to provide any other in a 
 fufficient quantity. But of the refpedtive 
 or compaiative goodnefs of all the other 
 kinds of timber for particular ufes, I 
 
 am unable to judge. There is anb- 
 
 \ 
 
 ther obvious reafon alfo why the ftep- 
 pings of , pods and' uprights lliould 
 foon decay, befides their touching the 
 
 ground, 
 
V 
 
 ( 37 ) 
 
 I 
 
 ground, from which the infecSlion of 
 the rot is received. The end of every 
 poft is fawed off, and if this be done with 
 a coarfe inftrument, it is left fpongy, 
 with the longitudinal fibres fliook or 
 broken a confiderable way within the 
 extremity of the wood. In this ftate the 
 ends of the ports murt be apt to abforb 
 from the ground the pernicious moifture 
 or exhalation, which being retained, and 
 fpeedily pervading the whole internal 
 fubrtance, this may be rotted, while the 
 external furface, efpecially if painted, 
 appears to be perfect. Artificers can tell 
 by the found of any fubrtance whether 
 it be healthy or decayed, as accurately as 
 a mufician can dirtinguifh his notes. 
 Thus a bricklayer rtrikes a wall with 
 his crow, and a carpenter a piece of tim- 
 ber with his hammer. Timber affedled 
 with the rot^ yields a particular found 
 when rtruck, but if it were painted, and 
 the diftemper h^d made much progrefs, 
 
 , C ^ with 
 
( 38 ) 
 
 with no fevere ftroke the outlide breaks 
 like a fliell. 
 
 I am pretty certain that in fitnations 
 obnoxious to this cliflemper, painting 
 forw^ards its progrefs, and probably in 
 this manner. If the moifture be ab- 
 forbed from the ground into painted 
 w'ood, it will be confined .there, the paint . 
 when dry forming a cruft, which pre- 
 vents every degree of exhalation, de- 
 priving, at the fame time, the wood of 
 the falutary influence of the open air; 
 and the moilture thus abforbed runs 
 through, and irifidioufly defti'oys the 
 whole fubftance. But if the wood were 
 not jjainted, fome portion of the moif- 
 ture would exhale to the furface, and 
 be diflolved -by the circumambient air. 
 If there were flaws or jundtures in the 
 wood, the rot might fliew itfelf fooner, 
 hut the decay of the wood would be 
 ' flower. 
 
 In fome fituations wooden pofts, fixed 
 8 
 
 in 
 
( 39 ) 
 
 in the ground fpeedily decay, not per- 
 haps by the ro/, but by fome property of 
 the ground accelerating its natural decay. 
 To prevent this, it is cuftomary to dip 
 the ends in melted pitch, or to give 
 them two or three heavy coats of tar;' 
 but many have doubted the efficacy or 
 propriety of this method. It is clear 
 that in fixing the pofts,‘ fome part of any 
 brittle matter muft be ffiivered off, and 
 a fmall vacancy may, admit the mifchief; 
 or if any moifture ffiould infinuate be- 
 tween the coat and the wood, the injury . 
 might be forwarded, and not prevented. 
 An apparently more reafonable method, 
 much pradtifed alfo, is, to fcorch the foot 
 of the poft in fuch a manner that the 
 outfide texture may become harder and 
 defer from the llirivelling of the wood ; 
 as the Indians burn the points of their 
 fpears, giving to them by that. method 
 almoft' the hardnefs and lliarpnefs of 
 
 metal. It is remarkable that in fir de- 
 \ 
 
 C 4 ftroyed 
 
( 4° ) 
 
 llroyecl by the ro/, there is not the leaf!: 
 remnant or veftige of refin or turpen- 
 tine, which in fa6l feems to be the lub- 
 Itance firft preyed upon. From thefe 
 premifes we may prefume to come to. 
 another conclufion, that in places fubje^Sf 
 to the rot^Jir is the mojl unJit kind of thn- 
 
 V 
 
 her to be ufed\ and perhaps to another, 
 that timber fixed in fuch places, Jhould 
 Jland a year or more before it is painted^ 
 or that it never Jhould be painted. There 
 is one pannelled roprn in this towp, 
 which was never painted, and inftead 
 of offending, it is rather agreeable to 
 
 ' I 
 
 the eye. 
 
 In hazardous places, it would be a 
 great prefervative to pofis fixed within 
 doors, if the communication between 
 them and the ground were to be cut off 
 by fome fubffance that could fuftain no 
 injury, or which w'ould not convey the 
 rot. Thin plates of iron or tin, firft oc- 
 curred to me as moft fuitable to this 
 
 purpofe ; 
 
.( ,41 ) 
 
 purpoie ; but probably a plate of flieet 
 lead, of a proper fize, would' anfwer • 
 better. 
 
 S'" 
 
 In the counting-hpufe of a merchant 
 in the city, the wood was yery fubjedl to 
 the rot, and in order to cure it, a brick 
 arch was thrown underneath the count- ' 
 ing-houfe and o’v^er a cellar, but after a 
 certain time the diftemper returned, 
 though it was lels rapid in its progrefs. 
 In this cafe I fufpecSl: that the arch of 
 the vault was covered with the rubbifli 
 of the old corrupted niaterials, or other 
 unwholefome ftufh Had this been co- 
 vered with broken glafs or clean peb- 
 bjes, pr been covered with good mortar. 
 Of had a brick floor been run over the 
 arch, or had the room been fet over the 
 arch, upon caft-iron piles, I apprehend 
 the diftemper would have been pre- 
 vented, • 
 
 In the courfe of this fummer a perfon 
 difcovered the floor of a fitting parlour, 
 
 to 
 
( 4 ^- ) 
 
 to be almoft wholly, cleftroyed by the rot. 
 
 I 
 
 When the floor was taken np, an im- 
 menfe quantity of the fungous web, 
 which ever accompanies the ro/, was 
 found between the floor and tbe ground. 
 
 I 
 
 To prevent the diftemper in future, 
 the ground was paved with ftone, and the 
 new floor laid upon the pavement. It 
 remains to be proved whether the dif- 
 temper Avill return; but unlefs the ftones 
 were hard and found, and laid fo accu- 
 rately as to interrupt all communication 
 w'ith the ground, I fufpedl it will. All 
 the tainted ground fliould have been 
 cleared away, and the vacuity filled up 
 with healthy materials, void, if fuch 
 could be procured, of all vegetating prin- 
 ciple; or if this could not have been 
 done, it would have been better to have 
 made the pavement with hard, glazed, or 
 ' vitrified bricks, fet in a thick bed of 
 frefli mortar, or terrace, than with any 
 kind of {lone. 
 
 Drynefs 
 
( 43 ) 
 
 Drynefs and warmth feem at the firft (/,[ 
 
 view, as if they would greatly reilft, if _ 
 
 not perfectly abolilh, this diftemper, 
 
 Thele relate to the air, unleft by a great 
 degree of heat the nioifture of the earth <■ 
 
 or ftones could be abfolutely done away, 
 or the quality of the earth changed by jj: 
 
 actual burning, or perhaps by a free ufe 
 of quick lime, which would produce an " 
 
 equivalent effedl. I have lately heard*of 
 two accounts which go againft this opi- 
 nion, but one of them is taken from the 
 newfpapers. The hearth ftone, of a very 
 large fize, in a kitchen, was faid to be 
 raifed out of its bed by a vail; number of 
 fmail fungi growing underneath. This 
 cafe is imperfeil, as it did not appear 
 whether this circumftance was local, or 
 whether any other part of this houfe was , 
 infected with the rot\ but it fliews that ; ' 
 a very coniiderable degree of heat does ' 
 not hinder the generation of/«;?^7, which ■ 
 invariably make a part of the ro/, though i 
 
( 44 ) 
 
 I it would be prefuming too much to fay 
 that all ground clifpofed to produce every 
 kind of fungus^ is infected with the rot. 
 In the houfe of a friend of mine the ends 
 of the beams which fupport the floor of 
 a parlour over a kitchen in conftant ufe, 
 were aftedled within the wall to inch a de- 
 gree, that the floor was very near falling 
 into the kitchen. On inquiry I found that 
 the fame circumftance had happened a 
 few years ago, when the houfe was re- 
 paired at a great expence. This is not 
 only a proof that Ample warmth does 
 not prevent the rot^, but of the infldious 
 manner alfo in which this fometimes 
 makes its progrefs. 
 
 In fome diftridts one certainly hears of 
 many inftances of the rot, while in others 
 there is a total exemption from it. I very 
 much doubt whether this diftemper has 
 ever been heard of in many parts of the 
 country, though in others the value of 
 property (in houfes) is very much de- 
 
 bafed 
 
I 
 
 ( AS ) 
 
 / 
 
 bafed by it. All this may be recohCiled 
 to the idea of native ground, uncorrupt- 
 ed, not producing the rof, by fuppoling 
 that the fac'e of a country has been par- 
 tially or generally very much altered 
 by accidental caufes, that thefe may 
 have occurred more frequently in fome 
 places than in others, or that fome na- 
 tive foils may from’ flight caufes, be 
 more prone to produce the rot than 
 others. I have heard it alTerted that in j 
 fome parts, fruit trees, efpecially thofei 
 of the more delicate kinds, become af- 
 fected with a diftemper which in feven 
 or eight years deftroys them. This has i 
 by fome been affigned to the importa- 
 tion of diftempers with foreign trees. 
 The leaves, or fomething blown from 
 the Lombardy poplar, are fufpedled to be 
 particularly injurious to fruit trees ; but 
 thefe are both in management and cul- 
 ture ab origine, rendered fo artificial, that 
 one is not furprifed with' any new dif- 
 
 pofition 
 
pofitlori they may acquire. In a very 
 hanjdfome avenue of elms which leads 
 to the houfe of one of ,my friends, and 
 which was planted about fixty years ago, 
 though the trees are full grown and ap- 
 pear generally healthy, of late, every 
 two or three years, one of them has fail- 
 ed. They firft ceafe to bear leaves, the 
 bark becomes difcoloured, and between 
 this and the bole there are an infinite 
 number of infe61s, probably not the 
 caufe, but confequence, or effedf of the 
 decay ; intimating alfo the parts firft dif- 
 tempered. It was propofed to cut off the 
 tap root topreferve the reft, on the com- 
 mon notion, that when this dips beyond 
 a certain depth, it may reach a bed of 
 fomething noxious which it imbibes and 
 conveys to the tree. But on inquiry the 
 tap root was found to have been already 
 cut, and a flooring of bricks laid to pre- 
 vent its regeneration. It feems from this 
 precaution that former trees had fuffered 
 
 m 
 
V 
 
 .( 47 ) 
 
 in the fame manner; or perhaps this 
 
 method had been pradtifed to make the 
 
 / 
 
 trees grow fafter at the expence of their 
 duration, as was done, according to the 
 account given by a traveller, with the 
 avenues leading to one of the palaces in 
 Spain, which prematurely growing, foqn 
 decayed. In the firfl: defcription of Bo- 
 tany Bay, it is faid that many of the trees 
 appeared as if they had been ftruck by 
 lightning, though it is poffible this 
 might be attributed to fimilar caufes 
 with the trees to which we have here al- 
 luded. In St. James's Park there are at 
 all times examples of trees with this ap- 
 pearance. In fome Spanijh plane trees, 
 planted near the new lodge in the 
 Green Park, there is at this moment a 
 very curious circumftance. The outer 
 bark of every tree is fcaled off, but whe- 
 ther it be a morbid or natural effe£l in 
 that kind of tree I cannot tell, though I 
 
 was 
 
( 45 ) 
 
 » 
 
 Avas told it occurred annually in trees of 
 this kind. 
 
 The rot has appeared in fome churches, 
 and in one the progrefs has been fo fpeedy, ' 
 and the neceffity of repairing fo frequent, 
 as to create a grievous expehce to the pa- 
 riflaioners. Here it will often be impof- 
 fible, or, which is nearly the fame thing, 
 improper to remove the ground, though 
 difpofed to* produce the rot ; yet I think 
 it might be prevented by the folloAving 
 method. The pews feem to be the prin- 
 cipal parts which can be infefted, and 
 inftead of flooring them on the ground, 
 
 I fliould propofe, that two or more of 
 thefe Ihould be built on one frame, 
 which inftead of refting on the ground, 
 fliould ftand on a proper number of call' 
 iron piles or cafters, by which the com- 
 munication with the ground or wall 
 would be hindered; and if the conjedture 
 of the caufe of the rot be juft, the pews 
 
 would 
 
( 49 ) 
 
 Would eltape any injury. But to render 
 the fuccefs more certain, it would alfo be 
 proper to pave the ground with fome 
 firm ftone or hard bricks. For the houfes 
 of the parochial clergy in fituations fub- 
 je<5l to the ro't^ I have a notion there is 
 a faving claufe with refpeil to dilapida- 
 
 ■I 
 
 , tions, but the expence mull fall fome- ii 
 
 where, or the houfes would come down. !| 
 
 'll 
 
 If an incumbent fhould arrive at old ii 
 
 ' { 
 
 age, keeping fiich a houfc in comfort- j 
 
 able repair, would in his life-time be a ^ 
 
 terrible dedudtion from the profits of 
 
 any living. 
 
 The roty as far as I know, does not af- 
 feB metals farther than as common 
 moifture, and no metallic fubiiance will'^^'^'^ 
 conduet the rot. It is curious to fee a ' ’ 
 
 door perfeilly found hanging on a poll: ? 
 
 fo much decayed, that it would not bear • 
 
 new ftaples or hinges to be fixed. This | 
 
 mull arife from the interruption of all j 
 
 communication with the decayed poll , 1 
 
 D by 
 
 
n 
 
 
 
 ( 50 ) 
 
 i 
 
 by the hinges, on which the rot cannot 
 make any impreffion, or which it cannot 
 pafs, or by which its peculiar quality 
 will be corre£ted. 
 
 Clofe to the houfes of many gentle- 
 men, for the purpofe of levelling or. 
 raifing.the ground, it is often neceflary 
 to bring materials from fome other place. 
 There has been much work of this kind 
 about Kenfington Palace. For fuch in- 
 tentions, great care is to be taken that 
 healthy materials are ufed, otherwife the 
 rot may be brought to the houfe if there 
 be no area ; or if there be, it often creeps 
 along the planks or pther fupporters of 
 ftone fteps, or in fome neglefted place, 
 and then it will increafe like the polypus, 
 if it finds any moift and decayed matter, 
 on which it can fix. Of whatever mate- 
 rials fuch ground is compofed, a long 
 time paflTes before it is perfectly dry or 
 fettles firmly. 'Tt is apt to be mofiTy, 
 emitting a peculiar, and not an agreeable 
 
 fmell, 
 
 
 
 
 it 
 
 A 
 
V 
 
 ( 51 ) 
 
 fmell, on the evening of a hot day, per- 
 haps for a hundred years after it was 
 layed. 
 
 It has been rnuch the fafliion of late, 
 to fix to the freehold many pieces of 
 furniture, as wardrobes and the like; 
 but in houfes fubjedl to the ro/, this 
 flioulh be ftudioufly avoided. 
 
 'Almoft every perfon can recoliedl the 
 ftate of much of that ground in the vi- 
 cinage of London which is now covered 
 with fair or magnificent houfes. How 
 the timber may ftand in many of thefe, 
 cannot as yet be afcertained, but the pro- 
 fpedl is, for many reafons, unfavourable. ;+•• 
 The foundation of every houfe mufl: be 
 layed on the true natural ground, but 
 this is not a fufficient fecurity unlefs 
 care be alfo taken to procure healthy 
 materials for filling up. vacancies, and per- 
 haps by firfl fkimming off and clearing 
 away any corrupted materials which have 
 been laid on its fite. I doubt it is the 
 
 D 2 
 
 ar 
 
 e.- 
 
 practice 
 
 - 
 
 ' y, j 
 
 
 
I 
 
 ( 5^ ) 
 
 prailice on thefe occafions, to take as 
 much of the gravel and better materials 
 as can be difpofed of with advantage for 
 other ufes, and then to fill up vacancies 
 with the cheapeft rubbifli that can be 
 gotten. But the expence and hazard of 
 this is generally left to the tenant or pur- 
 chafer of the houfe. A finall piece of 
 ground behind a houfe bought by a gen- 
 tleman I know, was fo excavated, that at 
 one time he paid fifty guineas merely 
 for carting the fcrapings of a turnpike 
 road, before it was brought to a proper 
 level. It is however very likely, by 
 choofing fuch materials, that he has pre- 
 ferved his houfe from the roA 
 
 The diftemper of which we are fpeak- 
 ing, is called by the general name of rot, 
 or dry- rot, but it may perhaps be difco- 
 vered, at fome future time, that there are 
 many varieties both of the diftemper and 
 its caufes. The prevailing opinion is well 
 known that it is a fpecies of vegetation, 
 
 but 
 
( 53 ) 
 
 but without deciding with fufRcient ac- 
 curacy upon the primary or predifpofing 
 caufe, or what the nature of that vegeta- 
 tion is. Some have fuppofed it to be of 
 the animal kind, and probably becaufe 
 of the obfervation that places in which 
 fnails have been decayed, do not fail to 
 produce mullirooms ; which has led, if I 
 miftake not, to a doubt whether mufli- 
 rooms were of the anirnal or vegetable 
 tribe; or becaufe no man has yet been 
 able to diftinguifli where the animal 
 kingdom ends and the vegetable begins, 
 or that no language can exadtly define 
 an animal from a vegetable, though 
 every one can clearly diftinguifh them 
 in his own mind, The firft efFecT which 
 earth capable of producing the rot lliews, 
 is in its being continually moiftef than 
 healthy earth, but the moifture ' is not 
 the fubftance of the difeafe, 'no more 
 than the matter of the fmall-pox is the 
 infeding principle, which is of the mofi: , 
 
 D 3 fubtle^ 
 
( 54 ) 
 
 fubtle nature, and only mixed or enve- 
 loped with the matter as its vehicle. So 
 I the moifture in earth impregnated with 
 the ro/, does not feem to be the principle 
 1 of the ro/, but it is merely the vehicle or 
 eondudlor of the miafmata or primary 
 principles of that diftemper. It would 
 be worth while to try ground which 
 produces the ro/, as well as v>^ood affedfed 
 by it, with eledtric experiments, whether 
 it abounds with, or is deficient in ele6tric 
 ' fire ; but there is a multiplicity of things 
 ' w'hich an ingenious man, who could 
 fpare time, might try, for the purpofes 
 of inveftigating either the caufe or the 
 effecl of the rot ; and if he had the faga- 
 city or good fortune to difcover a certain 
 method of preventing it, he would do a 
 very effential fervice to fociety. 
 
 When timber becomes afieftcd with 
 the rot, it is the medullary part which 
 firft fuffers, and as .this lies in different 
 portions in various parts of the timber, 
 
 according 
 
V 
 
 ( .55 ) 
 
 according to the ftraightnefs or obliquity 
 of the longitudinal fibres, fo the blotches 
 or tokens are of different fizes, and fcat- 
 tered irregularly over the furface of the 
 wood; but the fawed -ends or fides of 
 wood univerfally exhibit the firff; tokens 
 of its being infedled by producing the 
 fungus. This, which as far as I know 
 may have a proper name with natu- 
 ralifts, has exactly the fmell, and fome- 
 thing of the look, of a common muffi- 
 room, and this fungus is alfo fometimes 
 found behind pannels, yet I think never 
 unlefs there be fome aceefs for the air, 
 and perhaps a certain degree of conftant 
 or occafional moifture. In fome places 
 I have found what might be called 
 the fkeleton of a fungus., when from 
 the interruption of moifture, or from 
 its utter decay, the wood was no 
 longer capable of fupporting or re- 
 newing that which had been before 
 formed. When the rot mantles over a 
 
 D4 
 
 brick 
 
. ( 56 ) 
 
 brick wall, it has much the appearance 
 of a thick fpider’s web, and in its prin-' 
 
 V 
 
 cipal feat, where it has materials enough 
 to work upon, or by which it can be 
 nouriflied, and where it is not for a long 
 time interrupted, there is ufuaUy found 
 a large congeries of fluff of the fame 
 kind ; not, I apprehend, formed without 
 order, but lying regularly in Jirata, All 
 thefe fliould be obferved with -more care, 
 and fo important a circumflance as the 
 rot or cancer in wood, as it maybe called, 
 fhould not be fuffered to pafs longer with 
 fo little attention. 
 
 I cannot conclude thefe obfervations, 
 flight as thc}^ are, without taking fome 
 notice of the means which have been de- 
 'vifed or p'ra<£lifed for preventing the rot^ 
 by applications to the timber itfelf; with 
 a view of rendering wood impervious to, 
 or capable of refifling its influence. The 
 principle of all thefe means may be ex- 
 plained in two views; firfl, to fill up all 
 6 the 
 
( 57 ) 
 
 the interftices or cells of which timber is 
 phiefly compofed, with fome imperifti-’ 
 able matter, or by fome contrivance to 
 corrugate the timber, that the cells may 
 be obliterated, or fufficiently clofed, fo as 
 not to admit of the diftemper, fomething 
 in the manner of tanning leather; fe^- 
 condly, by foaking timber in fome fluid 
 impregnated with certain fubftances that 
 fliould aSt as an antidote to the diftem- 
 per, though put into conta<ft with it, or 
 to render wood impenetrable by it. 
 
 Profeflbr GraJJinan of Stettin has pro- 
 pofed a method of rendering timber ufed 
 hi building fhips more durable, and in- 
 dued at the fame time with particular 
 powers to refift the worm. Whether the 
 profeflbr’s method would, if it were prac- 
 ticable, have any power in' preventing 
 the rot in timber ufed in buildings, I 
 cannot tell, but will beg leave juft to 
 
 mention it, according to my apprehen- 
 lions of its purport. 
 
 He 
 
( 58 ) 
 
 He aclvifes the oaks to be felled green, 
 that is while the Tap is riling, and then 
 the timber to be made and kept perfedfly 
 dry, for fo long a time that all its native 
 moifture may be exhaled. The timber 
 is then to be foaked in a 'ley prepared 
 
 'from mineral coal and turf, and fo loaded 
 with llyptic or rather antifeptic particles, 
 that fuch an additional firmnefs may be 
 given to the timber as lhall make it far 
 more durable ; and the materials -with 
 which it is imbued fliall polTefs qualities 
 fo noxious to the worm.2& to deftroy it, or 
 render wood impenetrable by it. From 
 w'hat I have feen, this preparation of 
 timber, though it might endure longer, 
 would make a feeble relillance to the 
 worm, and would not be of any great 
 fervice againft the diftemper of which 
 we are fpeaking ; not to mention that 
 the procefs is too intricate and expen- 
 
 V 
 
 five to be pradtifed with timber ufed in 
 buildings. 
 
 While 
 
( 59 ) ' 
 
 While we are endeavouring to deftroy 
 or to fufpend the operation of the native 
 principle which is fuppofed ultimately 
 to caufe the decay of timber, or to qua- 
 lify it better for particular ufes, it be- 
 hoves us to be careful that we do not in 
 thefe attempts introduce other principles 
 of decay ; a circumftance to which atten- 
 tion has not always been paid. On the 
 whole, it may be doubted, whether by 
 any fuch means, greater advantage be 
 obtained, than merely by keeping timber 
 a fufficient length of time before it is con- 
 verted to its particular ufes. 
 
 It has been propofed to foak timber 
 intended for ufe in places liable to the 
 rot in a folution of vitriol (copperas), or 
 other fubftances of that kind, fo long 
 that it fliall be impregnated with them 
 through its whole fubftance. Of the ef- 
 fe£l of thefe methods I cannot fpeak, 
 having never feen them tried, but in( 
 my own opinion, no timber, however 
 7 prepared, 
 
( 6o. ). 
 
 prepared, will long be able to refill the 
 rot^ or do more thaia retard its pro- 
 jgrefs. 
 
 Artificers are frequently called when 
 the rot appears, to give their opinion 
 and aflillance in preventing its progrefs, 
 and they gravely recommend it to be 
 waflied with copperas water, or water 
 with new-flaked lime, and the like ; 
 and they are not, to be blamed becaufe 
 they know but little of what other peo- 
 ple are ignorant. Thefe will often de- 
 itroy the fungus which has appeared, 
 and the knowledge of this elFe<5l from, 
 fuch fubftances, may lead to the ufe of 
 them, in the firfl: inftance, to the ground, 
 or to llones layed over fuch ground; 
 though fcorching the part affedled with 
 a hot iron would be, in many cafes, a 
 preferable method. But the truth is, 
 the timber is gone before the fungus 
 makes- its appearance, fo that every me^ 
 thod of this kind mull of neceflity fail. 
 
 It 
 
( 6l ) 
 
 It being therefore evident that the rot is 
 incurable by any method with which 
 we are now acquainted, all our atten- 
 tion is to be employed in difcovering 
 the moft effedtual means of preventing 
 the diftemper ; and with this view 1 hope 
 the preceding obfervations may not be 
 altogether ufelefs. 
 
 THE END. 
 
 
 
 
 
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