38 



BULLETIN 510, U. S. DEPARTMENT OF AGEICULTUKE. 



WOOD PRESERVATIVES IN THE LUMBERYARD. 



Aside from the advisability of preserving permanent structures in 

 the lumberyard by the use of antiseptics applied to or injected into 

 the -wood, the question of preserving the lumber itself from incipient 

 infection until it reaches the consumer is one which merits careful 

 thought. During the past decade the use of soda (sodium carbonate 

 or bicarbonate) dips to prevent blua stain has become general 

 throughout the southern pine belt. Within the writer's own experi- 

 ence, sawmill men who in 1909 scoffed at such a measure had within 

 three or four years fallen in with the procession and were enthu- 

 siastic advocates of it. As yet the idea of dipping the lumber to 

 prevent infection from true wood-rotting fungi has not been con- 

 sidered by the lumber- 

 men. The soda dip is 

 not sufficient to accom- 

 plish the desired end, 

 so we must look else- 

 where for a suitable 

 preservative. Mercuric 

 chlorid is a hazardous 

 thing to use on general 

 stock, on account of its 

 extremely poisonous 

 nature, But is very effi- 

 cient and safe enough 

 for special purposes. 

 Zinc chlorid is objec- 

 tionable mainly on ac- 

 count of its capacity to 

 attract moisture. Of 

 the remaining colorless 

 salts in use for wood 

 preservation sodium fluorid or some colorless salt of hydrofluoric 

 acid would probably meet the needs of the situation A^ery well. So- 

 dium fluorid is highly toxic to fungi, but can be handled by worlanen 

 with no danger of poisoning. It is colorless, easily soluble, and can 

 be handled in any way that the soda dip can. It is more effective 

 than soda and so could readily be substituted for it, thus protecting 

 against both the blue stain and the wood-rotting fungi by a single 

 treatment. 



This whole feature of dipping lumber in this way to keep it in 

 a clean condition for the consumer must necessarily involve the 

 close cooperation of millmen, wholesale men, and retailers. The 

 millman may feel indifferent to the proposition, claiming that the de- 



PI02F 



Fig. 39. — Broken foundations, a result brought about 

 by not reinforcing the concrete. The company later 

 embedded some old 20-pound steel rails in the con- 

 crete near the top. 



