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TESTIMONIALS.

conducive throughout to their preservation for amuch longer period than that during which a boxor safe would be in contact with fire in the succes-sive conflagration of the parts of a building; nogreater heat than 212° will pass through this mediuminto the interior —a temperature perfectly harmless tobooks , papers , parchments , or even bank-notes;the cause of the exhaustion of the moisture beingso protracted, is its being sheathed and protectedfrom rapid vaporization in the absorbent non-conductor. In long continued heat, the non-conductor discharges its pyroligneous acid, which,combining with the alkali, forms a carbonaceouscrust or pyrolignate of potass—the worst conductorof heat known; and from within this shelter thepapers or books slowly give out again the largevolume of steam that has been passed into and con-densed in them , reacting most favourably in keepingdown their own temperature, that of the box orsafe, and the surrounding fire. The tea-kettle,boiling at 212°, in immediate contact with red-hotfire, into which a handful of bank-notes or gun-powder may be placed with safety, simply andaptly illustrates this principle. Another beautifuland forcible illustration of its extraordinary pre-serving capabilities, may be shown in a very simplemanner, by folding a piece of common writingpaper into the form of a tea-cup, having a wirecircle inside, and another outside, round the top,tied together with small binding-wire, and two half