PREVENTION AND EXTINQ UISEMENT OF FIBES. 151 



iron, clay, etc. A French journal recommends washing the wood-work 

 with a solution of ordinary pearl ash, then applying several coats of the same, 

 thickened with clay and flour paste, after which a composition of glue thick- 

 ened with iron filings, pulverized brick and ashes ; this will resist fire for 

 five hours and prevent the wood from ever bursting into flames, i. e., cause 

 it to so resist the ravages of fire as at most only to be reduced to coals and 

 ashes, without increasing the conflagration by additional flames. Under 

 most circumstances lime mortar is found to resist the spread of the flames 

 about as efl'ectually as any other coating, besides being far cheaper than 

 most of them. A writer in the London Science Review for September, 1872, 

 states that after the conflagration of Paris is was generally found that with 

 good plaster-work over them beams and columns of wood were entirely 

 protected from the fires. In cases where limestone walls had been utterly 

 ruined on the outside by the fiames, the same wall internally escaped al- 

 most unscathed, owing to their being coated with plaster. Stone stair- 

 cases well protected by plaster were fire -proof. 



Thus it will be observed that the alkalies ajad the alkaline earths possess 

 remarkable fire-proof qualities, and that paints and other coatings composed 

 of them wholly or in part may be depended upon to at least materially re- 

 tard the progress of the flames in any ordinary case of fire, if not to check 

 them altogether. It will also be noticed as we progress in the discussion of 

 this subject that they figure prominently in nearly all of the proposed 

 means for preventing the spread of the flames in conflagrations. 



In the few experiments I myself have made with fire proof coatings, I 

 have found none superior to those first named, viz : the water glass com- 

 positions, in efficiency and applicability to fine work. I think for use in cheap 

 structures, more especially factories and warehouses where inflammable 

 materials are handled, a mixture of animal glue with ashes and lime or salt 

 will be found much cheaper and nearly as efficient. 



Such coatings as these are also especially and imperatively demanded in 

 our steamboats, public halls and theaters, where the otherwise rapid com- 

 bustion of the light and fanciful wood-work, curtains and scenery endangers 

 human life more than almost any other circumstances. 



III. The grand object, however, of all of our investigations iniJ this 

 direction, is the discovery of some means of rendering the substance of the 

 wood itself incombustible. Having accomplished this, we may regard our 

 houses as quite safe, and not before, for as long as it is impossible to exclude 

 the air from them or build them perfectly solid, fires are liable to be kindled 

 and will spread, and no matter with what coatings we may cover the wood- 

 work, long continued and fierce heat will crack them off or penetrate to the 

 inflammable material beneath ; but when we can render the wood itself act- 

 ually fire-proof, at so low a price as to give the benefit of the discovery to 

 all, conflagrations need no longer be feared ; for a material of this kind will 

 be found superior to stone, brick and even iron itself in adaptability for 

 building purposes. 



