C. K. OGDEN
 
 PHILOSOPHICAL 
 
 INQUIRY 
 
 ON THE CAUSE, 
 
 WITH 
 
 DIRECTIONS TO CURE, 
 
 THE 
 
 DRY ROT 
 
 IH 
 
 IBuittifngaf* 
 
 BY JAMES RANDALL, ARCHITECT. 
 
 Opinioaum commenta delet dies, nature judicia contirmat. Cicero, 
 
 LONDON : 
 
 PRINTED FOR THE AUTHOR ; 
 
 AND SOLD BY J. TAYLOR, AT THE ARCHITECTURAL 
 LIBRARY, HIGH HOLBORN. 
 
 1807.
 
 StacK 
 Anne* 
 
 501.1896 
 
 PREFACE. 
 t 
 
 To treat a novel subject in a 
 novel manner, appears, at first 
 view, to follow as naturally as cause 
 and effect ; and bolder speculists 
 would, no doubt, in the height of 
 their frenzy, anticipate a success 
 proportionate to their expectations. 
 
 Before the Author enters upon 
 his subject, he thinks it necessary 
 to state how far, and on what
 
 VI 
 
 grounds, he means to rest his pre- 
 tensions to novelty. In the first 
 place, the subject itself has some 
 claim to this distinction, notwith- 
 standing some essays that have 
 been written concerning it ; and, 
 secondly, his manner of treating 
 it, and the remedy proposed, will, 
 he flatters himself, confirm the 
 justice of his remarks. 
 
 The subject is one of those, 
 which, of all others, has, perhaps, 
 been the most neglected, and by 
 those who were the best qualified, 
 and the most capable of devising a
 
 Vll 
 
 remedy ; the consequence has been, 
 that the Public have been, and still 
 are without any adequate means of 
 effectual assistance in cases of real 
 danger. Under these impressions, 
 and being himself of a profession, 
 which often exposed him to the 
 complaints of those affected by it, 
 he undertook the present Treatise, 
 with a hope of stimulating inquiry 
 upon a subject r which is rendered 
 of considerable importance, on ac- 
 count of the devastation produced, 
 and still producing, in some of the 
 finest buildings of the country. 
 Having also observed the confusion 
 existing among naturalists, and
 
 VIII 
 
 others, respecting the cause of this 
 phenomenon, and believing that 
 no system can be useful, unless 
 previously appreciated and defined, 
 he instituted experiments, in order, 
 if possible, to establish his facts ; 
 and he had the satisfaction to find, 
 that his preconceived opinions were 
 completely verified and confirmed 
 by the event. These experiments 
 were not made hastily, or at ran- 
 dom, but were the result of a series 
 of observations, made in different 
 places, and under circumstances, 
 that must have convinced the most 
 sceptical and uninformed.
 
 IX 
 
 Respecting the mode of inves- 
 tigation adopted, his scientific 
 Readers, he trusts, will offer no 
 objection ; as they will admit, that 
 this phenomenon could no other- 
 wise be satisfactorily, or fully ex- 
 plained, but by reference to chemi- 
 cal applications ; a circumstance 
 with which the more he considered 
 it, the more he was convinced ; 
 and the first experiment that he 
 made confirmed his opinions. Whe- 
 ther these opinions are just, or his 
 success has been complete, must 
 be left to the candour of intelligent 
 men, and the evidence of time. 
 To the impartial opinion of his 

 
 X 
 
 countrymen he humbly submits 
 his theory, experiments, and facts ; 
 actuated by no other wish, in thus 
 appearing before them, than that 
 of promoting useful science, and 
 contributing to the public welfare. 
 With these considerations, he offers 
 his little Treatise to their notice, 
 44 careless alike of censure or of 
 praise." 
 
 JV'0. i , Upper 
 
 Fitzroy Square.
 
 ON THE 
 
 CAUSE OF THE DRY-ROT. 
 
 JLHE Dry-rot presents a singular pheno- 
 menon to the eye of the attentive observer. 
 From a careful examination of its ap- 
 pearances, the most extraordinary result is 
 exhibited, no less curious in its nature than 
 incomprehensible in its cause. To those 
 who have heard of it, or witnessed its ravages, 
 it must afford matter of astonishment, that, 
 in the present improved state of arts and 
 sciences, nothing yet has been done to 
 analyse its properties, or arrest its destructive 
 progress. 
 
 During the practice of my profession, I
 
 have had an opportunity of examining and 
 making some experiments, with a view to 
 ascertain its nature and origin ; and from 
 these I was induced to believe, that fungus 
 is a gaseous residue. Subsequent observa- 
 tions and experiments having convinced 
 me that fermentation always takes place in 
 the vegetable matter destroyed, previous 
 to the appearance of fungus, it followed 
 as a necessary consequence, that the libe- 
 rated gases afford a direct germinating pa- 
 bulum to this peculiar vegetation. 
 
 The rot is known to builders by the 
 prodigious quantity of fungus formed on 
 every part of the decaying wood. Its ap- 
 pearance often varies, depending wholly 
 on the situation where it is engendered. 
 That which is most commonly found is 
 fleshy to the touch, adheres firmly to the 
 wood walls, and every contiguous sub- 
 stance, and branches out into, apparently, 
 strong fibrous roots. It occasions a gradual 
 decomposition of the wood, beginning at
 
 thesurface, and, finally, proceeding through 
 the whole mass. If any portion, however, 
 remains exposed to the atmosphere, the 
 destroying principle of the fungus is ar- 
 rested. Thus, floors often appear perfect 
 to the eye, when nothing is left undestroy- 
 ed but the part immediately in view. 
 Painted wood-work is wholly decomposed ; 
 the paint preventing a spontaneous oxy ela- 
 tion of its surface. 
 
 As a means of repairing those places that 
 are infected by the Dry-rot, I shall detail 
 the plan adopted in the one above-men- 
 tioned, which fully exemplifies the inef- 
 ficiency of the present remedy. On a 
 removal of the boards, the whole superficies 
 exhibited a complete area of fungus, the 
 wood remaining only in the condition of 
 fragments. It emitted a strong odorous 
 scent, which so affected the workmen em- 
 ployed in clearing away, that they grew 
 faint, complained of head-ache, with pain- 
 ful respiration, and were forced to discon- 
 B 2
 
 tinue their labour. Approaching the spot, 
 I experienced similar sensations. Upon 
 letting fall some lighted shavings, the com- 
 bustion instantly ceased. Although this 
 followed almost as a matter of course, yet, 
 nevertheless, from the symptoms and ap- 
 pearances that were exhibited, it shews 
 that the absence of oxygen has no effect on 
 this vegetation. After the fragments had 
 been removed, the earth was taken out to 
 the depth of eighteen inches, and it was 
 suggested to cover the new surface with a 
 stratum of lime core : this being done, the 
 floor was renewed, leaving a vacuum be- 
 neath it and the lime, and making drains 
 and perforations to admit the atmospheric 
 air. Thus, the usual experiments were 
 tried, with the addition only of the lime ; 
 but, a few months had scarcely elapsed, 
 when the fungus again appeared protrud- 
 ing over the perforations made for admit- 
 ting the air, and another alarming scene 
 was exhibited on clearing it away. A 
 lighted candle being forced into the va-
 
 cuum was immediately extinguished, and 
 upon following it with my hand, I felt a 
 considerable heat, which was likewise ap- 
 parent from the particles of water that were 
 perceptible upon all the adjoining surfaces 
 in contact with the atmosphere. 
 
 As these effects undoubtedly proceeded 
 from fermentation, a circumstance of 
 which I was fully convinced by further 
 examination, and from the fungus being 
 formed only on those parts that were im- 
 mediately in that state, it was evident, 
 that if, in the construction of buildings, fer- 
 mentation could be prevented among the 
 wood-work, fungus would not be formed, 
 nor the Dry-rot appear. 
 
 Taking it then for granted, that fermen- 
 tation is the cause, I conjecture, from this 
 discovery, that the liberated gases are the 
 essential materials from which the germi- 
 nation and fecundation of this plant are 
 produced, as they are formed only when 
 B 3
 
 circumstances have combined to produce 
 this extraordinary phenomenon. 
 
 Some earths promote fermentation by 
 the vapours they evolve ; and the ground 
 on which this floor was raised being arti- 
 ficially made, and abounding with vege- 
 table matter, I conclude, that the liberated 
 vapour adhered to the wood, and gave the 
 first spring or impulse to fermentation; 
 this, during its progress, destroyed the 
 proportion of ligneous particles, and pro- 
 duced those new vegetable forms, which 
 finding a nidus congenial with their na- 
 ture, rapidly propagated, and diffused them- 
 selves over the parent matter. 
 
 These appearances following so quickly 
 after the restoration of the new floors, ma- 
 nifest that the first cause of this phenome- 
 non was owing to a removal of the top of 
 the earth ; a circumstance more fully con- 
 firmed by the quantity of gas liberated 
 frgm its new surface. This gas consisted
 
 of carbonic acid and hydrogen, the latter 
 of which, meeting with the oxygen of the 
 atmosphere, burned, and produced water. 
 But if more atmospheric air had been pre- 
 sent, the oxygen, in my opinion, would 
 have predominated, and, although water 
 might have been formed, the remaining 
 hydrogen, with a portion of the carbonic 
 gas, would have been burned or destroyed. 
 Hence, a derangement of the elementary 
 particles would have taken place, and pre- 
 vented the vegetation of this fungus, the 
 other fecundating principles being absorbed 
 and dispersed, and leaving no pabulum be- 
 hind. This actually took place when 
 more atmospheric air was admitted, for a 
 final stop was put to the fermentation, and, 
 consequently, to the germination of the 
 fungus. 
 
 In all those cases that fell under my 
 
 inspection, wherever the atmospheric air 
 
 was introduced, it was admitted to act 
 
 thoroughly ; for, without this precaution, 
 
 B 4-
 
 8 
 
 I can assert, from experience, that it will 
 tend rather to promote than correct the 
 rot. Something useful on this subject may 
 be collected from Dr. Franklin's Essays on 
 Chimneys. The Doctor having there de- 
 scribed the proper mode of admitting air 
 in those cases, the same may be adopted 
 in its admission to floors; for, as he philo- 
 sophically proves, that currents are abso- 
 lutely necessary to supply the waste oc- 
 casioned by a continual discharge through 
 the chimneys, so it is equally necessary 
 that similar currents should be introduced 
 for the purpose of burning and dispersing 
 the different elements that are instrumental 
 in promoting the germination and fecun- 
 dation of this vegetable. It is also neces- 
 sary, that the supply of air should be con- 
 stant and equal to its waste and dissipation, 
 or not the smallest benefit will be pro- 
 duced. 
 
 Although this, when properly admitted, 
 may be safely employed, it is of too des-
 
 9 
 
 perate a nature to be introduced into houses, 
 so as to ensure effectual success; for which 
 reason it will he unnecessary to enlarge 
 upon it, especially as a remedy that is frc % e 
 from these inconveniencies will, hereafter, 
 be described. 
 
 It would add little, either to an establish- 
 ment of facts, or an elucidation of the na- 
 ture of this vegetable, to investigate mi- 
 nutely the various opinions entertained by 
 naturalists, concerning its origin and pro- 
 duction. They have, for the most part, 
 materially differed, and their researches 
 not being directed towards the fungus that 
 is protruded among buildings, which evi- 
 dently undergoes various impressions in 
 consequence of its peculiar situation, it will 
 not be correct, or proper, to form any con- 
 clusion from their opinions. Nevertheless, 
 in order to demonstrate the general notions 
 entertained on this subject, I shall state the 
 opinions upon which these notions have 
 been formed.
 
 10 
 
 The first, and indeed the most natural 
 hypothesis is, that they are propagated by 
 seeds. It was difficult, however, to ex- 
 plain this propagation ; the plants possess- 
 ing neither flowers nor leaves ; it was there- 
 fore boldly asserted, that they were depo- 
 sited in the earth by rains, and afterwards 
 absorbed into the roots and branches by 
 the capillary attraction that takes place in 
 raising the sap. This opinion, however, 
 did not pass without contradiction ; and 
 Marsigli, a modern naturalist, observing 
 that fungi were often without roots and 
 branches, imagined that they grew in 
 places where they met with an unctuous 
 matter, formed of oil mixed with nitrous 
 salt, which, by fermentation, produced heat 
 and moisture, and insinuated itself between 
 the fibres of the wood. Lancisi supposed 
 that this production owed its existence to 
 the putrefaction of vegetables. This spon- 
 taneous origin was likewise believed by 
 our own countryman, Dr. Darwin, who, 
 when describing the green vegetable matter
 
 11 
 
 floating on stagnant lakes, observes, " the 
 mucus, or mouldiness, that is seen on the 
 surface of all putrid vegetable and animal 
 matters has, probably, no parent, but a 
 spontaneous origin from the congress of the 
 decomposing organic articles, and after- 
 wards propagates itself." This, as Dr. 
 Priestley expresses himself, " is neither 
 more nor less than supposing the produc- 
 tion of organized bodies from substances 
 that have no organization, as plants and 
 animals, from pre-existing germs of the 
 same kind, plants without seeds, and ani- 
 mals without sexual intercourse." Never- 
 theless, the seed origin is still adhered to ; 
 which may, in some measure, be accounted 
 for, from the nature of the subject ex- 
 amined ; for fungus is found attached to 
 so many different substances, and the ex- 
 amination of these being confined to ap- 
 pearances only, it is evident, that whatever 
 inference may be deduced from one is 
 quickly destroyed by another, and a very li- 
 mited view alone obtained on the subject.
 
 Hence, I believe, that so far as relate 
 to the fungus in buildings, that these in- 
 quiries, although ingenious, are wholly 
 hypothetical f and have been promoted 
 merely to conceal an ignorance of what 
 still remains an impenetrable secret. I 
 am, nevertheless, far from denying the 
 existence of seeds, Nature employing so 
 many secret and extraordinary means of 
 accomplishing her various purposes. 
 
 If these plants, however, are propagated 
 from seed, they must be deposited by the 
 atmosphere, or exist in a state of mecha- 
 nical suspension in the sap of the wood ; 
 and with this view, fermentation appears 
 to be absolutely necessary to give the first 
 impulse to the cotyledon ; yet, were this 
 the case, these plants would be found only 
 on the parts that had undergone that pro- 
 cess, and other parts would be affected 
 only in proportion to the force and exten- 
 sion of the vegetation ; for fungus produces 
 decomposition only on the part on which
 
 13 
 
 it grows. In places, however, that have 
 been infected, this is so far from being 
 the case, that those parts that are remote, 
 and where it could scarcely have existed 
 in a state sufficient to impregnate the seeds 
 of fungus, roots of this plant have been 
 often found. Hence, / conclude, that 
 the liberated gases escape from one part to 
 another in a state of fermentation, carrying 
 with them the direct pabulum of the em- 
 bryo plant ; the seed of whicli having 
 been, by the atmosplierc, previously de- 
 posited on the wood, germinates, appro- 
 priating its cohesive particles to its sup- 
 port. 
 
 New buildings always experience fer- 
 mentation in a greater or less degree. There 
 are, however, some peculiar agents essen- 
 tially concerned in its production and sup- 
 port. These, while the atmosphere is 
 present, it destroys by ignition and absorp- 
 tion ; and, in order fully to comprehend 
 this property of the atmosphere, it is of
 
 considerable importance to notice the 
 changes that take place in the vegetable 
 matter occupied by the fungus plant, and 
 the alterations in the air itself, as these ob- 
 servations will lead us to a knowledge of 
 their chemical properties. 
 
 No alteration is observable in the wood, 
 until the root be firmly attached ; neither 
 is any plant formed except in places where 
 the fermentation has derived all its advan- 
 tages from the agents concerned in its pn> 
 duction and support, and completed the 
 final putrefaction of the sap. At this pe- 
 riod begins a new arrangement of vegeta* 
 ble materiality, which, from a white moul- 
 dy film, proceeds to long fibrous roots, 
 adhering firmly, and producing the same 
 apparent change in the wood as mastica- 
 tion, or distillation, by depriving it of its 
 adhesive qualities, and terminating in a 
 complete decomposition, which cateris 
 paribus follows in proportion to the growth 
 of the plant. This decomposition is, in
 
 15 
 
 some instances, effected so rapidly, that I 
 have seen new wood in a few weeks utter- 
 ly destroyed, leaving nothing but dust, as a 
 proof of its existence. 
 
 Fir wood is more often attacked by this 
 vegetation than oak, to the latter of which 
 it is seldom so destructive. Except when 
 contiguous to the former, it never exhibits 
 a fibrous appearance, but a grey kind of 
 mould, which js decomposed in the same 
 manner as the fungi, though not so rapidly, 
 being frequently confined to a single joist, 
 and sometimes only to a part. The plants 
 of this class (cryptogramia) are constantly 
 produced in all situations, and during every 
 season ; and as Cit. L. Reynicr says, 
 " whose form is constantly determined by 
 the nature of the substance on which they 
 grow, and is constantly the same in similar 
 circumstances, although they do not ap- 
 pear at stated seasons, like other vegetable?, 
 also present new facts." It is not long since 
 Cit. Vantenant observed a boleta, of a new
 
 IG 
 
 and singular shape, on a human body. From 
 this fact it is evident, that the seeds for 
 this plant float in the air, and constantly 
 pervade all matter, vegetating wherever 
 they find a pabulum and an elevation of 
 temperature, these being the essential 
 agents necessary for their development. 
 
 As this phenomenon appears to be the 
 result of temperature and liberated gases, 
 it will be necessary to examine the changes 
 that they undergo in places infected with 
 fungus rot. These changes being consi- 
 derable, and owing to a volatilization of 
 some of the vegetable principles, or of 
 their parts, and these being very pernicious 
 and assuming various aspects, arising either 
 from an absorption of part of the oxygen, 
 or a combustion of the hydrogen, or pro- 
 bably from the formation of a certain 
 quantity of carbonic gas ; while these pro- 
 cesses are going on, a part of the hydro- 
 gen may escape, carrying with it a small 
 quantity of carbon, which being divided
 
 17 
 
 into minute particles by the aeriform solu- 
 tion, burns either at the same time or im- 
 mediately afterwards. Thus the air, at the* 
 last term of its alteration, may be entirely 
 deprived of its oxygen, contain also, a 
 large portion of water, the greater part 
 of which, not being preserved in a dissol- 
 ved state, is precipitated, and becomes 
 charged with a portion of vegetable mat- 
 ter in a state of vapour. Hence the for- 
 mation of fungus, which this vapour im- 
 pregnates in greater or less abundance, 
 according to the quantity of seed that is 
 present. This theory is sufficiently con- 
 firmed by inspecting and examining the 
 state of this vegetation. Water, for in- 
 stance, is always present, hanging about 
 in particles, and the air (as before ob- 
 served) is entirely deprived of its oxygen. 
 Thus the vegetation of fungus appears to 
 differ from that of all other plants, which 
 owe their existence, in a more or les s 
 healthy state, to the presence and absorp- 
 tion of this gas : fungus, on the contrary, 
 
 c
 
 18 
 
 grows more rapidly, and is more healthy 
 in its absence : for the gases liberated from 
 the wood, during its putrefaction and de- 
 composition, being mostly carbonic acid 
 and hydrogen gas, which, by their union, 
 afford a direct pabulum for the germina- 
 tion of the seed. From their rapid irv 
 crease, it is reasonable to conclude, that 
 this plant possesses the proper organs for 
 appropriating its own constituent princi- 
 ples; and from the change experienced 
 by the wood in the production of this new 
 vegetation, which parts with all its origi- 
 nal properties ; the new substance increas- 
 ing in health and vigour in proportion 
 to the rapid alteration in its composition, 
 I conjecture, that a part of the liberated 
 carbonic gas, is spontaneously decomposed; 
 and it is this supply of carbon that affords 
 such a rapid source of vegetable materia^ 
 lity to these plants. This will not be 
 thought an extravagant supposition, con- 
 sidering the quickness of their growth, 
 and that every other species of vegetation, 
 is produced in consequence of plants pos-
 
 sessing a power of appropriating carbon 
 from water, * air, &c. to the various pur- 
 poses of leaves, flowers, and fruits. 
 
 During the course of my observations, I 
 have had an opportunity of witnessing the 
 complete growth of a fungus, under the 
 following circumstances : several pieces 
 of fir-wood having been promiscuously 
 thrown together in a damp situation, and 
 left there only a few weeks, upon acci- 
 dentally removing a part of them, they 
 were found to be in a high state of fer- 
 mentation, and almost wholly enveloped 
 in a white film of mould, which, on fur- 
 ther examination, appeared to be a com- 
 plete fungus. An opportunity was now 
 afforded to ascertain, from actual demon- 
 stration, the effect of this vegetable on 
 wood previously prepared', of which I 
 availed myself, and shall hereafter describe 
 the result> Although so short a time had 
 
 * M. Chaptal says : " La decomposition de 1'eau est 
 prouvee, non seulement dans le vegetal, raais dans 1'ani- 
 mal." c 2
 
 20 
 
 elapsed since these planks had been thrown 
 together, a decomposition had taken place 
 on all the wood occupied by the fungus, 
 and I am convinced that, in a few days, a 
 fungus would have been produced from 
 the whole of the mould. To this pheno- 
 menon I paid particular attention, as it so 
 immediately confirmed my opinion of the 
 Dry-rot, in all cases, arising from a pre- 
 vious state of fermentation; and I think 
 that the most sceptical would have been 
 equally convinced. 
 
 Entertaining, as I do, no doubt on the 
 subject, I shall, therefore, consider it as so 
 produced, and that it owes its first spring, 
 or motion, to the various causes that are 
 constantly affording the essentials to this 
 phenomenon. Such are, first, a super- 
 abundance of sap in the wood ; other new 
 materials ; exhalation, and, in fine, any 
 other cause capable of affording the neces- 
 sary quantities of air and water; both of 
 these (to a certain degree) being absolutely 
 necessary to its production and support.
 
 21 
 
 This fatal destroyer proceeding only 
 from one cause, it may be removed by 
 means of an artificial preparation ; and, as 
 it should act not only on the sap, but the 
 wood also, it appeared to me, that the 
 most effectual remedy would be oryda- 
 tion. With this view, I oxydated several 
 pieces of wood, both with nitric acid and 
 fire, and placed them in the most favoura- 
 ble situation among this pile. Portions of 
 the same plank, and of similar dimen- 
 sions, were placed constantly near them. 
 During the first twenty days, no particular 
 change was visible in either of the pieces. 
 At the expiration of this period, on re- 
 moving one of the unoxidated portions, I 
 discovered particles of mould forming 
 between the lamella of the wood, but not 
 the least alteration was perceptible in the 
 others, although surrounded by wood co- 
 vered with and producing fungus. In 
 sixty days, the pieces, and all that were 
 near them, excepting the four previously 
 oxidated, were entirely decomposed, ex- 
 c 3
 
 hibiting nearly the same appearances as 
 have before been detailed. 
 
 From these facts, It is obvious, that oxy- 
 dation is a certain remedy for the Dry-rot; 
 these experiments having been made un- 
 der the most favourable circumstances. In 
 order, however, to ensure its complete 
 success, it will be necessary to oxydate the 
 whole of the wood ; that is, the ends as 
 well as the other parts ; for having, in a 
 subsequent experiment, neglected this pre- 
 caution, and there being also some vents 
 in the wood, the fungus seed germinated, 
 and produced a partial decomposition ; 
 beginning at the ends and in these vents. 
 As there will be a*difficulty in oxydating 
 the wood thus venting, and an uncertainty 
 likewise, in other respects, attending tim- 
 ber in this state, it would be better not to 
 use it in whole pieces, or in situations where 
 danger may be anticipated. With respect 
 to spontaneous oxydation, or volatilization 
 of the wood and sap. this will have no ef.
 
 feet in preventing its fermentation or future 
 fluidity ; the volatilization only rendering 
 the one brown and the other concrete. 
 This concretion may, from local or extra 
 neons causes, acquire sufficient moisture to 
 afford and encourage fermentation ; it is, 
 therefore, necessary, that the wood be 
 rendered indestructible by an antiseptic re- 
 medy, and this appears to be completely 
 obtained by oxydation ; which not only 
 deprives it of its fluid particles, but, like- 
 wise, so prepares its surface, that nothing 
 can vegetate upon, or stimulate the con- 
 creted sap, so as to render it elastic; for it 
 is this elasticity that gives the first impulse 
 to fermentation, which is followed by an 
 elevation of temperature, or, more pro- 
 perly, a disengagement of latent caloric, 
 and, finally, a complete fungus. This 
 effect may be produced, from the causes 
 above stated, in wood known to workmen, 
 either as seasoned or unseasoned ; for al- 
 though this wood be perfectly dry, it con- 
 sists of the same identical materials as it 
 C 4
 
 24- 
 
 did before it became so ; and this drying 
 being, as before observed, nothing more 
 than the volatilization, or burning of its 
 hydrogen by the oxygen of the atmosphere, 
 which renders the wood brown and the 
 sap concrete; the latter, receiving a suffi- 
 cient quantity of moisture, either by the 
 union of gas or otherwise, may regain its 
 original elasticity ; for unless it possesses 
 elasticity or fluidity, it cannot ferment, and 
 that it does so, after its spontaneous con- 
 cretion, is evident from the circumstance 
 of fungus being protruded on its surface. 
 If we, likewise, take into consideration 
 the numerous causes that concur to pro- 
 duce this stimulus in buildings, where 
 exhalations are constant, it will appear 
 rather a matter of chance than otherwise, 
 that they are not oftener destroyed by this 
 vegetation ; for, instead of leaving their 
 interior parts exposed, so that the materials 
 may be volatilized of their gaseous particles, 
 they are, frequently, covered up, and 
 immediately enclosed with as much care
 
 as is taken to render them elegant in the 
 finishing. Thus the timber is exposed to 
 the reception of the fermenting stimuli 
 which are attracted from the adjoining 
 walls ; and in all cases where the Dry-rot 
 does not follow in consequence of this in- 
 consistency, it is owing to the atmosphere 
 finding its way through some channel to 
 counteract and disperse the putrefaction. 
 
 Having so far stated the facts attendant 
 on this phenomenon, I shall further de- 
 scribe the most simple and easy methods 
 (from actual experiments) both of prevent- 
 ing its formation in new, and removing and 
 curing it in old buildings. Aware of the 
 apparent difficulty of this undertaking, to 
 those who, instead of attempting a cure, 
 think only of restoring, it may be necessary 
 to observe, that restoration, in those places 
 already in a state of vegetation, tends only 
 to promote the vegetation of fungus, by 
 affording it fresh materials for its sup- 
 port.
 
 Country houses experience the Dry-rot 
 in their basement and ground stones. When 
 it reaches the latter, it may be considered 
 as only an extension of the power of ve- 
 getation, promoted by the former. In 
 these places, it most generally arises from 
 the ground being thrown up round the 
 walls, to extend the landscape, as far as 
 the cills of the ground-floor windows. In. 
 such a situation, it is sufficiently obvious 
 what affords the stimulus to the fermenta- 
 tion. It is the continual moisture which 
 the earth gives out to the adjoining wall, 
 and which is transmitted to the wood in 
 contact. Thus a decomposition rapidly 
 takes place, and sometimes produces vege- 
 tation in the course of a few weeks. 
 
 In the construction of basement stories, 
 where the landscape cannot be dispensed 
 with, an alteration might be made by an 
 area, or a vacuum, about two feet in dia- 
 meter round the story, leaving a sufficient 
 number of air-holes with iron registers. I
 
 have seen this precaution adopted in one 
 or two instances, with the desired success; 
 and it will always add considerably to the 
 warmth of the story, by rendering the wall 
 comfortable and dry. 
 
 The principal timbers in a building, on 
 the soundness of which so essentially de- 
 pend both the lives of its inhabitants and 
 the property of the landlords, and the 
 plates and girders, being most generally 
 the first infected, it would be a prudent 
 and salutary precaution, to submit them 
 invariably to the process of oxydation, 
 together with all the parts inserted in the 
 walls; these being generally the first to 
 receive the stimulus. As the state, how- 
 ever, in which timber is used for the dif- 
 ferent purposes of building, prevents an 
 easy mode of oxydating by the first natu- 
 ral process, and as this might, perhaps, 
 rather intimidate as hazardous than be 
 adopted as useful ; and further, as wains- 
 coting, dadoes, tVc. could never be sub-
 
 mitted to this process without spoiling them; 
 it became necessary to inquire what other 
 method could be adopted, to produce the 
 same effect, without a similar inconve- 
 nience. This leads me to an explanation 
 of the acid process of oxydating by 
 affinity. 
 
 It is well known to chemists, that most 
 acids possess this power in proportion to 
 the force with which they retain their oxy- 
 gen ; and as this force is overcome when- 
 ever the oxygen meets with a base to which 
 it has a greater affinity, it is evident, from 
 the quick separation of oxygen, and the 
 consequent oxydation of wood by the 
 nitric acid, that this effect is produced by 
 its superior affinity to the constituent prin- 
 ciples of the vegetable only. Although 
 the vegetable matter is more powerfully 
 excited by this acid, yet I have found 
 that the sulphuric may be employed with 
 equal success, and will certainly be more 
 economical, and less liable to any objec-
 
 tion in practice. What renders them more 
 useful in preserving from further mischief 
 and expense, the buildings infected by the 
 Dry-rot, is, that they may be employed, 
 with few directions, by common workmen; 
 but with girders, or other large timbers, 
 it will be better to apply the common pro- 
 cess of oxydation. In order to facilitate 
 the operation, they should be previously 
 prepared, by washing them with a solution 
 of nitre ; this would render it not only 
 more certain, but likewise more complete. 
 I am induced to recommend this method, 
 from a knowledge that this kind of timber 
 is generally prepared for its respective uses 
 in places where no danger is to be appre- 
 hended from the experiment. 
 
 Such numerous facts and so many cir- 
 cumstances have concurred to convince me 
 that oxydation is a certain remedy for this 
 pestilential phenomenon ; and knowing 
 the great expense and trouble annually in- 
 curred in many edifices in this country,
 
 where nothing but repair after repair is re- 
 peated, producing no other effect than 
 eventually to endanger their equilibrium, 
 and deprive the country of some of its 
 best specimens of architectural beauty, the 
 duty I owe to society, and the attachment 
 I feel for such embellishments, have led 
 me to communicate the result of those ex, 
 periments that have proved efficacious and 
 certain. 
 
 Respecting the process of oxydation, 
 nothing would have prevented its being 
 sooner introduced into practice, but the 
 difficulty of succeeding upon all the va- 
 riety of wood-work necessary in our man- 
 ner of finishing buildings. They who 
 were aware of its efficacy by the common 
 method, had, probably, no idea that a 
 similar effect could be produced by the 
 powerful acids. My experiments have 
 established the fact, and the anti-vcgetating 
 surface of the wood, after their applica- 
 tion, affords a conclusive proof.
 
 The indestructibility given to wood by 
 this operation, arises, according to Dr. 
 Bancroft, " from its absorption of oxygen, 
 in which state it will resist the combined 
 action of sun, air, moisture, &c. for hun- 
 dreds of years ;" so that all decay, however 
 anticipated or expected, may be entirely 
 prevented by this previous preparation. 
 There is one precaution necessary in ef- 
 fecting this by the acids, that is worthy of 
 notice, namely; that the surface of the 
 wood, submitted to the operation, should 
 be wrought, or planed. This is indispen- 
 sible, unless a great quantity of the acid 
 be employed. As the same beneficial ef- 
 fect, however, may be produced with a 
 much kss quantity, and a proportional 
 diminution of expense, I presume that no 
 one will object to this preliminary mea* 
 sure. 
 
 The indestructibility of vegetable oxide, 
 or charcoal, has long been known. That 
 the ancients were acquainted with it, it is
 
 obvious, from the piles on which the fa- 
 mous temple of Ephesus was built, having 
 been thus previously prepared ; nor have 
 there been wanting instances of its anti- 
 destructive, or preservative powers, within 
 our own knowledge. " The beams of 
 the theatre of Herculaneum were con- 
 verted into this oxide, by the lava which 
 overflowed that city ; and, during a lapse 
 of eighteen hundred years, they have re- 
 mained as entire as if they had been oxy- 
 dated but yesterday ; and they will, pro-, 
 bably continue so to the end of the world." 
 Many other instances might be adduced, 
 but from their similarity, they are, I con- 
 ceive, unnecessary to be mentioned. In 
 the oxydation by the acid process, what 
 renders it of more essential importance in 
 practice is, that it may be used for timbers 
 that arc already in buildings (provided 
 they are not yet infected by fungus). Con- 
 sidering this advantage, it must be evident 
 that a great saving may be made in the 
 repairs by a judicious selection of such as
 
 33 
 
 are not seized on by the fungus, or in a 
 state of decomposition ; as these parts may 
 readily be oxidated by the diluted acid. 
 This is not the only beneficial effect result- 
 ing from the oxydation of beams by acids, 
 as may be gathered from the following 
 remarks of Huber,* who says, that the 
 vapour of sulphuric aether, placed under 
 a recipient of atmospheric air, prevents 
 seed from growing without altering the 
 quantity of oxygen in the air. The same 
 happens with camphor, oil of turpentine, 
 assafoetida, vinegar, and ammonia. Hence 
 it appears that asther, evolved from these 
 fluids, prevents germination ; and as there 
 is always some asther disengaged from the 
 acids, in their separation and fixation, I 
 conjecture that this disengaged asther may, 
 by its volatility, produce the most salutary 
 effect in repairs for the Rot. 
 
 * Bull, des Sci. 
 D
 
 Having thus far described a scries of 
 facts and experiments which have come 
 within my own observation, I shall, as a 
 farther illustration of this phenomenon, 
 collect the opinions advanced, and the re- 
 medies adopted, by others ; beginning with 
 the house belonging to the Society of 
 Arts, &c. This building, as I am in- 
 formed, was not long since attacked by 
 the Rot, and its consequences having been 
 represented to the Fellows of the Society, 
 they directed Dr. Higgins to examine, and 
 adopt such precautions against its ravages, 
 as he should think proper. I have been 
 subsequently informed by a gentleman, 
 who, at that period, was a member (al- 
 though I can find no minute made of 
 the transaction, in the Society's Annual 
 
 Register,) that Dr. H completely 
 
 succeeded in, not only, stopping its pro- 
 gress, but, likewise, in effecting a perfect 
 cure, by the following singular antidote. 
 After having restored such timbers as had 
 been attacked by the plant, he directed
 
 35 
 
 them to be washed with a solution of 
 caustic ammonia. I did not hear of this 
 till after I had applied the nitric acid ; but 
 it must appear obvious, that the effect pro- 
 duced on the wood will be similar. At 
 any rate, the Doctor seems fully aware of 
 its being the nidus for the seed's devclope- 
 ment, and that by burning its surface, he 
 prevents its formation, and destroys its 
 growth. 
 
 As the ammonia possesses no particular 
 advantage that may not be fully obtained 
 by the nitric acid, excepting a more co- 
 pious disengagement of aether, and its ex- 
 pense being much greater, it will, I con- 
 jecture, diminish its comparative claim to 
 general use. 
 
 There are some circumstances attending 
 the buildings in the Adelphi, which, in 
 some measure, may elucidate the nature 
 of this vegetation. They may be divided 
 into two : first, their situation ; and, se- 
 D 2
 
 36" 
 
 condly, their locality, which rendered it 
 necessary to construct a basement story 
 lower than was convenient for domestic 
 purposes. It was, therefore, appropriated 
 to stables, and other uses belonging to the 
 river. Hence one of the essentials to this 
 vegetation was supplied by the dung and 
 exuvias ; and this too in the very place 
 where, from its effluvia, it could diffuse 
 the necessary pabulum, and, probably, the 
 seed, to the superstructure of the build- 
 ings. 
 
 As the moisture of the place, must in a 
 greater or less degree, have produced a 
 state of fermentation among the wood, it 
 must be referred to these two causes only. 
 It may be objected to this hypothesis, that 
 if the effluvia of the dung and exuviae 
 form the pabulum for the seed, that the 
 fungus would be found on all the wood 
 exposed to it. This would certainly be the 
 case, were it not for the access and egress, 
 and the influence of the atmosphere. Ad-
 
 57 
 
 mitting, however, that these objections 
 were removed, an elevation of tempera- 
 ture is necessary to give a spring to the 
 cotyledon. As the temperature, in this 
 situation, can never be regular, or of suf- 
 ficient duration, to give the stimulus to the 
 vegetation, unless in parts where the fer- 
 mentation cannot be checked by a con- 
 stant supply of air; in such it is common, 
 and often more destructive than in other 
 places. If a review be taken of its nature, 
 and the causes of the germination and 
 fecundation of its various species, it will 
 be found, that elevation of temperature is 
 an essential requisite ; nor will it be difficult 
 to prove, that no developement whatever 
 takes place without it. Considering the 
 variety of this vegetable, and the causes 
 which concur in its reproduction, I cannot 
 avoid imagining, that the original seed is 
 the same in all ; and that its appartnt va- 
 riety arises wholly from the different mat- 
 ter in which its radicle fixes itself. In- 
 stances of which are to be found in ngri- 
 D 3
 
 38 
 
 culture, and in some parts of the country 
 more than others, where, especially at 
 particular seasons, the corn is destroyed by 
 a species of fungus, which, from its ap- 
 pearance, and its mode of attack, is pre- 
 cisely the same as that of all others. As 
 Mr. Kerby's remarks on it will farther 
 illustrate this similarity, and, in some mea- 
 sure, lead to a more general knowledge of 
 its habit and mode of attack, I shall submit 
 these in his own words : " I have seen 
 more than one half an ear of corn affected 
 by this fungus, where the other half was 
 sound and good. Sometimes it injures all 
 the stems that spring from the same root ; 
 at other times, part of them escape. I ne- 
 ver could discover any diseased appearance 
 about the root. The ear is often affected 
 before it emerges from the soliuni vaginus, 
 or hose." * In this instance the plant is 
 liable to those vicissitudes that characterise 
 
 * Linncan Society's Transactions.
 
 other living substances, and the result is 
 similar. These plants exist and germinate 
 on vegetable matter only : they extract, by 
 the extremity of their vessels, the juices 
 that nourish them, elaborating and assimi- 
 lating them to their own substance. It 
 must be obvious, that this extraction and 
 elaboration cannot proceed beyond the 
 powers of the fungus vessels ; and these 
 juices being but scantily supplied in an 
 ear of corn, the plant must be proportion- 
 ally weak in its vegetation and effects; but 
 in the instances of buildings in which there 
 
 O 
 
 is a nidus, abounding with all the juices 
 necessary to promote the full power of its 
 organs, its results are proportionally great, 
 and its mischief extensive. The opinion 
 that this mischief is occasioned by insects, 
 cannot be supported by a single fact, and 
 appearances militr.te^trongly ag.iinst such 
 an hypothesis; for were this th? case, the 
 whole of the seed, or the part attacked, 
 would suffer, leaving or.ly the cortical part 
 as a proof of its existence ; for insects, liko 
 D 4
 
 40 
 
 birds, never destroy more of this part than 
 is necessary to enable them to obtain ac- 
 cess to its saccharine contents. The subse- 
 quent experiments, however, of this in- 
 genious divine, have set the matter at rest, 
 as far as relates to this subject. He says : 
 '' I happened to take some dust from 
 branded grains ; I think last year ; which 
 I laid by for future inspection. After I had 
 begun this paper, I strewed some of that 
 dust upon a piece of fine glass, and put- 
 ting it under a very strong magnifier, over 
 a reflector, was highly gratified with ob- 
 serving, that every particle of brand was 
 a globular seed ; not the least variation in 
 shape or magnitude was visible amongst 
 them." There can be no doubt of the 
 accuracy of this experiment, and the dis- 
 covery thereby made places the subject in 
 an obvious point of vjcw, as it refers to its 
 origin. From the above experiment, it is 
 evident, that this perpetuation is to be de- 
 duced from seeds (and not, as Dr. Darwin 
 conjectures, " from the congress of de-<
 
 composing organic particles"), and the 
 minuteness of their size could alone have 
 occasioned them to escape the attention of 
 those naturalists who have held a con- 
 trary opinion. M. Neckar, treating of 
 their generation, says, " they are always 
 formed when the parenchymatous, or cel- 
 lular suhstance, has changed its form and 
 function." Hence we must conclude, that 
 it is the degeneration of that part which 
 produces these bodies ; but can degenera- 
 tion, putrefaction, or any other state inci- 
 dent on the decomposition of vegetable 
 matter, create an organic substance ? Do 
 not we know that these seeds, from their 
 minutiae, must be dispersed through the 
 air ? and does it not follow that they will 
 germinate, whenever they find a pabulum, 
 or a convenient nidus ? In answer to the 
 advocates of spontaneous origin, Dr. 
 Priestley uses the following convincing ob- 
 servations : ff Still, completely organized 
 bodies, of specific kinds, are maintained
 
 to be produced from substances that could 
 not have any natural connexion with 
 them, or particular relation to them ; and 
 this I assert is, nothing less than the produc- 
 tion of an effect without any adequate 
 cause. If the organic particles, from 
 which an oak is produced, be not pre- 
 cisely an acorn, the production of it, from 
 any thing else, is as much a miracle, and 
 out of the course of nature, as if it had 
 come from a bean or a pea, or, absolutely^ 
 from nothing at all ; and if miracles be 
 denied (as they are, I believe, by all the 
 advocates for this doctrine of equivocal 
 generation), these plants and animals, 
 completely organized as they are found to 
 be, as well adapted to their destined places 
 and uses in the general system as the largest 
 plants and animals, have no intelligent 
 causes whatever, which is, unquestionably, 
 atheism ; for, if one part of the ^ystem of 
 nature docs not require an intelligent cause,
 
 neither does any other part, or the 
 whole."* 
 
 That the spontaneous origin was adopted 
 by its advocates, only from the difficulty 
 of accounting for the growth of these 
 plants in places wholly deprived of the 
 apparent sources of fecundation, is suffi- 
 ciently obvious, and must have been the 
 sole cause of these conjectures. But as the 
 seeds are invisible without the assistance of 
 a powerful magnifier, their suspension in 
 the air is certain, and I suspect that they 
 continue in this situation until their specific 
 gravity he changed, either by adhering to 
 other matter in the same state, or by absorp- 
 tion. As they must be dispersed in the 
 months of summer, and, for the most part, 
 plentifully ; and as, at this season, fermen- 
 tation and putrefaction are constant, and 
 these states produce not only an elevation 
 of temperature, but likewise an evolution 
 
 * American Society Paper.
 
 of gas, owing to the change that they ex- 
 perience, the pabulum for their devclope- 
 merit must be referred to this cause. 
 
 Experiments, and the facts deducible 
 from them, being the sole foundation and 
 effectual establishment of all philosophical 
 inquiries, it follows, that these facts, and 
 their natural phenomena, must be of essen- 
 tial importance in the present investiga- 
 tion. Under this impression, I shall select 
 some extracts from the papers, which, at 
 different periods, have been sent to the 
 Society for the Encouragement of Arts and 
 Commerce, in consequence of their en- 
 deavours (by the offer of premiums) to 
 stimulate enquiry into this phenomenon, 
 and thereby to benefit the public, by the 
 discovery of a tried and practical preven- 
 titive of the Rot. Although this object 
 may not have been, hitherto, fully attain- 
 ed, yet some of the papers already received 
 contain many useful facts ; and most of 
 them having occurred in places, and under
 
 45 
 
 circumstances, highly favourable to the 
 investigation, I trust, that, in selecting a 
 few of the most remarkable, it will be 
 believed, that I have no other object in 
 view than of rendering useful the synop- 
 sis of this inquiry. 
 
 The Society having repeated their pre- 
 mium, Mr. Batson, who was repairing the 
 mischiefs occasioned by the Rot, during 
 this period (1793), in a part of his house, 
 communicates the following particulars : 
 " The Dry-rot having taken place in one 
 of my .parlours in such a manner as to 
 require the pulling down part of the 
 wainscot every third year, and perceiving 
 that it arose from damp stagnant air, and 
 from the moisture of the earth, I deter- 
 mined, in the month of June, 1783, to 
 build a narrow closet next the wall, through 
 which the damp came to the parlour, 
 which had the desired effect : but though 
 it put a total stop to the Rot in the parlour, 
 4he evil soon appeared in the closet. Fungi,
 
 of a yellow colour, arose to a great degree 
 in various parts of it. In the autumn of 
 the year 1786", the closet was locked up 
 for about ten weeks : upon opening it,, 
 numerous fungi were observed about the 
 lower part of it, and a white mould was 
 spread by a plant, a vine, or sea weed ; and 
 the whole of the inside, china, &c. was 
 covered with a fine powder, of the colour 
 of brick-dust. It being then cleaned out, 
 1 soon perceived what, indeed, I did not 
 expect, that the evil had impregnated the 
 wood so far, as to run through every shelf 
 therein ; it had also seized upon and de- 
 stroyed, a moveable board for breaking 
 sugar upon. I therefore (in the year 
 1789) determined to strip the whole closet 
 of lining and floor, and not to leave a 
 particle of the wood behind ; and also to 
 dig out and take away about two feet of the 
 earth in depth, and leave the walls to dry, 
 so as to destroy the roots, or seeds, of the 
 evil. When by time, and the admission of 
 air and good brushing, it had become suf-
 
 ficiently dry and cleansed, I filled it of 
 sufficient height for my joists, with anchor- 
 smith's ashes, knowing that no vegetable 
 would grow in them. My joists were 
 sawed of their proper lengths, and fully 
 prepared ; they and the plates were \vell 
 charred and laid upon the ashes ; particular 
 directions heing given, that not any scant- 
 ling, or board, might he cut or planed in 
 the place, lest any dust or shavings might 
 drop among the ashes. 
 
 " My flooring boards being very dry, I 
 caused them to be laid close, to prevent 
 the dust getting down, which I thought, 
 in a course of time, might bring on a 
 vegetation. 
 
 " The framing for lining the closet was 
 then fixed up, having all the lower pan- 
 nels let in, to be fastened with buttons only, 
 that in case any vegetation should arise, 
 the pannels might, with ease, be taken out 
 to examine them. This having now
 
 48 
 
 been done upwards of six years, and nd 
 vegetation or damp appearing, the whole 
 of the pannels remaining in the same state 
 as when first put in." 
 
 That these facts are certainly valuable 
 needs no illustration. The fungus vegeta- 
 tion, however, must have been expected 
 when the air was thus excluded from the 
 closet ; for in a place like this, the action 
 of the atmosphere could alone preserve it, 
 unless some previous precaution had been 
 taken with the wood. It is evident from 
 Mr. Batson's observations, that moisture was 
 the original stimulus to the vegetation ; and 
 although this new erection of a closet 
 might have had the desired effect of pre- 
 venting vegetation on the wainscot, by the 
 formation of a vacuum ; yet experience 
 convinced him, that no such effect was 
 produced on the closet itself, nor could it 
 be expected, when the constituent parts 
 and fibres of the wood were considered ; 
 for it would be found that they would
 
 seize and absorb this moisture; and, con- 
 sequently, experience a change. As the 
 first alteration that vegetable matter under- 
 goes by such absorption, is fermentation ; 
 and as this state, from the evolution of its 
 pabulum, must have been the continual 
 source of the destruction of the wainscot, 
 it could not have happened otherwise than 
 that the shutting up of this closet should 
 have promoted it ; inasmuch as the pre- 
 sence of the atmosphere tended to derange 
 the equilibrium for its production, the 
 atmosphere having a particular effect upon 
 all wood ; and, under certain circumstan- 
 ces, tending more to its preservation than 
 almost any other power. 
 
 The next circumstance that strikes me 
 as worthy of observation in this ingenious 
 and valuable paper, is the novelty and 
 importance of ascertaining and appreciat- 
 ing the singular phenomenon that occurred 
 from the introduction of the anchor-smith's 
 ashes. That the cure, in this place, was 
 E
 
 50 
 
 entirely owing to their use, there can be 
 no doubt; especially as there had been 
 no previous measures taken to prepare the 
 wood (excepting the plates and joists) or 
 to obviate the percolation in the walls. 
 This percolation, in the first instance, was 
 evidently the cause of the fermentation, by 
 producing a change of state in the sap of 
 the wood ; and the ashes could have pre- 
 vented this hy no other means than by a 
 superior attraction. Mr. B. observes, I 
 filled it with anchor-smith's ashes, knowing 
 that no vegetable would grow in them:" 
 but the vegetable never did grow any 
 where but on the wood ; so that it must 
 be referred to their effect on this and the 
 air present, and not to them as an anti- 
 vegetating nidus. 
 
 My opinion is, that the whole of this 
 phenomenon arose from the oxydation of 
 the metallic particles of the ashes, and the 
 gases liberated from them; and that this 
 attraction occasioned a new arrangement, 
 which is obvious from the effect produced.
 
 51 
 
 Indeed, there is no way of fully account- 
 ing for this, but by anticipating their supe- 
 rior affinity for their vegetating principle. 
 That iron possesses this affinity for oxygen 
 is certain, from its attracting this principle 
 from air, water, &c. &c. Its attraction for 
 it is so considerable, that it will seize it 
 from almost every other substance, however 
 combined, and the result is the production 
 of an oxyde and an evolution of hydro- 
 gen. 
 
 That this principle in the iron, of tak- 
 ing the oxygen and evolving hydrogen, 
 was fatal to the vegetation, is certain from 
 the effects that were produced ; and it is 
 also certain, that hydrogen alone is fatal 
 to all germination. This has been shewn 
 by Dr. Carradori,* who says, " Achard, 
 in the first place, and, after him, other 
 philosophers, have shewn, that germination 
 
 * Journal de Physique, 
 E 2
 
 52 
 
 does not take place in any mephitic air ; 
 as, for example, inflammable or hydrogen 
 air, phlogistic or azotic air, which are 
 known to contain no oxygen ; whence it 
 was necessarily concluded, by a legitimate 
 inference, that of all the atmosphere which 
 we term the air, the oxygen is the only 
 portion necessary to germination ;" and 
 although the specific levity of the hydro- 
 gen might have anticipated its immediate 
 escape through the crevices of the floor, it 
 must be recollected, that a considerable 
 portion of carbonic gas must, likewise, be 
 present, and the difference of its specific 
 gravity must have detained the hydrogen 
 in a carburetted state. As all germination 
 is stopped in this gas, I conjecture that it 
 was: the gas, and the superior affinity only, 
 that prevented the vegetation. 
 
 This antidote is certainly valuable, and 
 its success may be relied on as certain in all 
 situations similar to that in which it was 
 employed by Mr. Batson. Nevertheless,
 
 in a general point of view, it is liable to 
 one formidable objection, and, particu" 
 larly, as it refers to its application to super- 
 structures. To those who are at all aware 
 of the construction of floors, however art- 
 fully done, it must be obvious, that, al- 
 though it might not be necessary to fill up 
 the whole vacuum between the joists, any 
 weight of the magnitude that ashes would 
 require to occupy all the intermediate space 
 in the area of a floor, would derange its 
 necessary equilibrium ; and as this de- 
 rangement would not be confined to the 
 timbers only, it is evident, that they are 
 inapplicable to such places. As iron pos- 
 sesses this property in the air of attracting 
 its vegetable stimulus, I concluded that a 
 compound of it, in a state of solution, 
 might be employed with equal success. 
 Impressed with this idea, I prepared wood 
 with a sulphate of it, and found, upon in- 
 troducing it into a place where fungi vege- 
 tated, that a most extraordinary phenome- 
 non took place, which, I was at first in- 
 E 3
 
 clincd to attribute to the very reverse of 
 what proved, from another experiment, to 
 be the fact. Every plant within its influ- 
 ence, that extended several feet in the area 
 of a circle, was so affected, that it withered 
 away, and a stop was put to the vegeta- 
 tion : nor did it, even after a long expo- 
 sure to the influence of the plant, lose its 
 anti-vegetating principle. From this ex- 
 periment a new fact appears, viz. that 
 the sulphate of iron is a destroyer of fungi, 
 and hence its importance may be conjec- 
 tured in correcting of them, particularly 
 in places where it is impossible to remove 
 all the wood attacked by them. The va- 
 lue of this antidote, in such places, will, 
 upon trial, appear sufficiently obvious. 
 
 The chemical phenomenon, however, 
 that attended this process, is the reverse of 
 what was produced by the iron itself; for, 
 instead of seizing the oxygen, as was the 
 case with the latter, it absorbs the nitrogen 
 only. But it must be observed, that these 
 are the two predominating ingredients of
 
 which the atmosphere is composed ;* and, 
 therefore, although the vapour only, which 
 it held in solution, was decomposed by the 
 iron, yet no decomposition is effected hy 
 the sulphate solution of this metal ; it is the 
 nitrogen alone that it absorbs, and which 
 would be restored entire, were a third body, 
 of superior attraction than either of the 
 former, to intervene. It appears very 
 probable, that to this absorption may be 
 attributed its power of destroying vegeta- 
 tion. This may be accounted for in two 
 ways; first, on a supposition that the at- 
 mosphere, from this reduction of its ni- 
 trogen, possesses too stimulating a power 
 for the assimilating organs of the plant : or, 
 secondly, to the avidity with which they 
 absorb the solution itself; which, from its 
 over-proportion, may become a poison. 
 That some such phenomenon does take 
 place, is evident from their quick* dissolu- 
 tion. 
 
 * In the proportion of O,22 of oxygen gas, and 0,/8 
 of nitrogen. E 4
 
 This vegetation then, having a stimulus 
 peculiar to its nature, which appears to be 
 
 * 
 
 fully demonstrable to our view, it becomes 
 a subject of curious investigation; and as 
 my purpose is to endeavour to counteract 
 its injurious effects, I shall select another 
 paper from the same source, as a farther 
 illustration of this important operation. 
 
 Mr. Johnson says : " Some time between 
 1771 and 1773, I went, at the request of 
 a friend, to the chapel of the Lock Hos- 
 pital, through curiosity to examine a pc\v 
 there, that had frequently been repaired 
 for damages by the Dry-rot. After a close 
 investigation, we found that it was the 
 operation of a plant, whose leaf resembled 
 that of the vine ; wherever it had touched, 
 the effect of its poisonous quality got 
 through the wood to the paint, which I 
 have se"en a mere skin. I proposed to 
 cover the floor with bricks, laid in mortar, 
 which was accordingly done. I called 
 twice since; the last time about seven years 
 ago, and had reason to think that it had
 
 57 
 
 never appeared again. The next oppor* 
 tunity of examining it carefully, was at 
 Mark Hall, in Essex. In a parlour there 
 were three pillars, of about ten inches 
 diameter, the outwood of which was be- 
 tween two and three inches thick. Two 
 of them were eaten through in less than 
 seven years, from the basis, about two 
 feet upwards within the hollow, and were 
 as rotten as if it had been the effect of a 
 hundred years standing. 
 
 " At another time, I saw it in a house 
 at Whitehall, built by Sir J. Vanbrugh. 
 The house is, I think, only two stories 
 high ; the plant had ascended to the upper 
 story, committing devastation on the wains- 
 cot all the way. It will destroy half-inch deal 
 in a year. I have had it twice in houses 
 I inhabited ; one in Suffolk, and the other 
 in Gloucestershire. I bore with the first ; 
 in the other case, I undertook, and did 
 stop it eventually. The cause is from the 
 floor being laid on the earth, which has
 
 58 
 
 been, where I have observed, of a gravelly 
 or sandy loam, the moisture from a water- 
 course at hand, or a northern aspect, where 
 the outer walls stand in a garden bed, so 
 that rain percolates, are great encouragcrs, 
 it requires moisture." After a few more 
 observations nearly similar to the preced- 
 ing, on a case at a botanist's, and the sur- 
 prise he felt on being told that it was a visit 
 from a plant, he observes : " In my own 
 case, I removed the original soil, near the 
 part affected, and supplied its place with 
 sand. I then placed pieces of tiles over, 
 putting thcrn under the wainscot, so that 
 it had no communication with the joist or 
 floor. Pillars, in like manner, should be 
 kept from the earth." 
 
 In these facts there is scarcely any thing 
 new, except the mode of cure ; and that 
 this is different from that of the former is 
 obvious ; but the effect 1 believe to be un- 
 certain, or at any rate applicable only to 
 one situation ; for of what service can the
 
 application of sands, tiles, and mortar be, 
 in roofs that are infected with this rot? 
 That it often begins in them, there are 
 numerous proofs, particularly in domes. 
 It is a well known fact, that the great dome 
 of the Bank of England, as originally 
 built by the late Sir Robert Taylor, was 
 destroyed by this Rot, while no other part 
 suffered. The timber - framing of this 
 dome was of good sound oak. I saw, 
 when at Paris, upon examining the dome 
 of the Pantheon, a fungus plant protrude- 
 ing between the crack in the covering, 
 near its base, which on touching crumbled 
 into dust, and was of that species found on 
 oak. There were also several of these 
 plants to be seen about the late dome of the 
 Halle-au-Blcd in the same city. I have 
 seen floors of upper stories, in all aspects, 
 destroyed by this Rot, when the ground 
 story remained perfect ; so that no infe- 
 rence can be drawn, as Mr. Johnson con- 
 jectures, from its being in the ground 
 story and the two-pair at the same time,
 
 that, therefore, the plant of the first had 
 ascended there ; for this plant is produced 
 only when the stimulating phenomenon is 
 present, and in each of those various pla- 
 ces, it must have heen present separately 
 to produce the germination. The remedy 
 adopted by Mr. Johnson may, in some 
 places, prove of essential service ; and* 
 indeed, I know of one instance, where, 
 after a great many repairs had been made, 
 it was employed with the desired success ; 
 with this only difference, that the ground 
 was covered with a floor of Yorkshire stone, 
 as a preparation for the wooden one. That 
 the exhalation from the earth was the sti- 
 mulus in all Mr. Johnson's cases, is certain 
 from the cures having been effected by its 
 prevention : but I have seen an instance, 
 in a ground-story, where it was not owing 
 to this cause, but to the carelessness of the 
 workmen, in leaving a quantity of shav- 
 ings under the joists, in a humid state, 
 which fermented, and produced large 
 fungi protruding on the wood. In fact,
 
 61 
 
 as it has already been observed, the re- 
 medy for this Rot, to be effectual, must 
 counteract this phenomenon. But to re- 
 turn to the remedy anticipated by Mr. 
 Johnson's method, which, from its not 
 being applicable to all cases and situations, 
 cannot, I conceive, be rendered generally 
 useful ; for, it is obvious, that it is adapted 
 to exhalation only, and even here much 
 must depend upon the materials employed, 
 and the quality of the workmanship. Re- 
 specting the causes and prevention of per- 
 colation and exhalation, which promote by 
 far the greater number of cases of Dry-rot 
 fungi, Mr. Ramsden Bramley's remarks 
 are both rational and scientific. He ob- 
 serves, that, " where houses are troubled 
 with damp walls, near to the earth's sur- 
 face, it is generally, if not universally, 
 occasioned by the percolation of water 
 from the higher adjoining ground, which, 
 thus intercepted in its current, attempts to 
 follow the general hydrostatic law, of ele-
 
 6*2 
 
 vating itself, by the syphon line, to a 
 height equal to that whence it had its ori- 
 gin. Thus in houses differently situated, 
 we see the damp arising to various degrees 
 of height on the walls, and those are pro- 
 bably all corresponding to the height at 
 which the moisture circulates in the ad- 
 joining ground . At its first entrance to the 
 building, and whilst the moisture is in 
 small quantities, the excavated part of the 
 foundation wall may absorb, and gradually 
 quit such proportion ; but the excess, as is 
 generally the case in moist weather, ex- 
 ceeding that power, the foundation stones 
 are then saturated in a more rapid propor- 
 tion than the adjoining rarified internal 
 atmosphere can evaporate. The watery 
 particles then creep up, in degrees pro- 
 portionate to the ascent from which they 
 originally descended, excepting when 
 prevented, or driven off, by the superior 
 heat of the adjoining rooms, when, in 
 addition to the disagreeable damp they
 
 (S3 
 
 cause, they frequently occasion considera- 
 ble damage to pictures, furniture, &c. 
 
 " Drains laid on ditto, athwart the as- 
 cending ground, with a very slight descent 
 or fall, and made of the depth of one yard 
 for each yard of ascent, and from the 
 foundation until equal to the height that 
 such damp ever rises, would, there is little 
 doubt, completely secure the house and 
 furniture from the inconvenience hitherto 
 sustained, and prove an effectual preven- 
 titive to most cases of Dry-rot, where it 
 originated in extreme moisture." 
 
 These remarks speak for themselves, 
 and, in the cases referred to, would, most 
 probably, effect what has been anticipated ; 
 but not being supported by actual experi- 
 ment, they cannot be pursued ; nor is it 
 certain that it would succeed in preventing 
 a vegetation of the fungi, although it 
 might remedy the damages to which fur- 
 niture, pictures, &c. arc exposed, At any
 
 rate, it is applicable only to the case of 
 percolation. He further observes : " I am 
 of opinion, that the fungus which per* 
 vades decaying wood, is not the first cause, 
 but an attendant on the peculiar state to 
 which such wood has been reduced by 
 previous causes. The dissemination of the 
 seeds find a proper bed, or nidus, like the 
 mushroom or toadstool, and there fix their 
 abode, and pervade the whole substance, 
 thus accelerating the general law of Pro- 
 vidence, which tends to make all matter 
 l\ -productive. 
 
 " Cellars, or such other places, should 
 be drained in the manner I have above 
 mentioned, by taking off the percolating 
 \vaier previous to its gaining admission to, 
 or contact with the walls; and it is proba- 
 ble that, in most cases, a single drain will 
 liau complete effect. It would, assuredly, 
 \vere it not for the variation of the earth's 
 internal strata, which is not easily discernir 
 ble. If attention to this rule were paid,
 
 65 
 
 previous to the building of any new streets 
 in towns, it would prove essentially useful." 
 This is all that can be said for it in the 
 present imperfect state of our knowledge 
 concerning it. It certainly may be useful ; 
 but there are no facts upon which we can 
 establish a position for general practice. 
 This, however, is not the case with any 
 of the previous antidotes, they being all 
 supported by well substantiated historical 
 evidence, and confirmed by facts deduced 
 from actual experiments. Hence this Rot, 
 however anticipated, may find its cure, 
 in whatever situation it makes its appear- 
 ance ; but, as was before observed, the 
 plant receives its pabulum from the fer- 
 menting wood, and, therefore, the cure 
 for the Rot must depend wholly on ob- 
 viating this state, or preventing its surface 
 from becoming a nidus for the develop- 
 ment of its seed. This phenomenon, 
 although not distinctly alluded to, appears 
 to have been anticipated by the methods 
 recommended by those gentlemen who
 
 have considered the subject; and, not- 
 withstanding I differ from them in the 
 mode of accomplishing my purpose, it is 
 that I sought a remedy for general purpo- 
 ses ; an event which, I think, will scarcely 
 be produced by any of the cases that 
 have, hitherto, been brought forward. I 
 have little to add, except to repeat that 
 o.rydation only can be relied on, in all ca- 
 ses, as an effectual cure. So confirmed 
 am I in this opinion, from the experiments 
 I have made in houses that are infected 
 (the publication of which is withheld only 
 on account of the dislike entertained to- 
 wards houses that are known to be thus 
 infected, and their consequent reduction 
 in value), that I hesitate not to offer it to 
 the consideration of an enlightened Pub- 
 lic. In what I have advanced, there is, 
 doubtless, much of repetition, and many 
 tedious details. This has, probably, arisen 
 from the principal facts being almost all 
 of a nature to lead to the same conclu- 
 sions : for in an examination of cases,
 
 67 
 
 where the appearances and resulls proceed 
 from fixed and limited principles, whe- 
 ther in nature or art, some little variety in 
 its treating should be, as a matter of 
 course, allowed. 
 
 FINIS. 
 
 Printed by Cox, Son, and Baylis, 
 Great Queen S'.rc-et.
 
 A 000 090 893 9