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beams of buildings in moist, warm situations, where 

 there is not a free circulation of air. It appears at first 

 in round, white, cottony patches, from one to eight 

 inches broad, which afterwards develop over their whole 

 surface a number of fine, yellow, orange, or reddish- 

 brown irregular folds, most frequently so arranged as to 

 have the appearance of pores, and distilling drops of 

 moisture when perfect ; whence its specific name. In the 

 mature state it produces an immense number of minute, 

 rusty sporales, which alight and speedily vegetate in the 

 circumjacent timber, however sound and dry it may ap- 

 pear, destroying its elasticity and toughness, and render- 

 ing it incapable of resisting any pressure, until gradually 

 it crumbles into dry, brown dust. This insidious disease, 

 once established, spreads with amazing rapidity, destroy- 

 ing some of the best and most solid-looking houses in a 

 few years. The ships in the Crimea suffered more from 

 this cause than from the ravages of fire, or the shot and 

 shells of the enemy. So virulent is its nature, that it 

 extends from the woodwork of a house even to the walls 

 themselves, and by penetrating their interstices, crumbles 

 them into pieces. " I knew," says Professor Burnett, 

 " a house into which the rot gained admittance, and 

 which, during the four years we rented it, had the par- 

 lours twice wainscoted, and a new flight of stairs, the 

 dry-rot having rendered it unsafe to go from the ground 

 floor to the bed-rooms. Every precaution was taken to 

 remove the decaying timbers when the new work was 

 done ; yet the dry-rot so rapidly gained strength that 

 the house was ultimately pulled down. Some of my 

 books which suffered least, and which I still retain, bear 



