22 BULLETIN 118, U. S. DEPARTMENT OF AGRICULTURE. 



ADVANTAGES AND COST OF BORAX. 



The great demand for borax, due to its uses in the arts and in the 

 household, has made this substance available in all parts of the coun- 

 try. It has the further advantage of being comparatively nontoxic, 

 noninflammable, and easily transported and handled, as it is a 

 powder. Thus borax is superior to most of the substances that have 

 been tested as larvicides. Several investigators (see Haselhoff, 1913) 

 have shown that in small amounts borax has a stimulating effect on 

 plant growth, while larger amounts are toxic. 



Borax is prepared from colemanite (calcium borate), which is 

 mined in California, and has the following composition: Boron 

 trioxid, 50.9 per cent; calcium oxid, 27.2 per cent; water, 21.9 per 

 cent. The crude colemanite was tested for its larvicidal action, but 

 this was so slight, undoubtedly due to its insolubility, that it was 

 discarded in favor of borax and calcined colemanite. Calcined 

 colemanite is prepared from crude colemanite by simply subjecting 

 it to high temperatures. 



The crude colemanite is not sold as such, but a considerable amount 

 of the calcined colemanite is used in various industries. The calcined 

 colemanite is a gray powder and is largely, but not entirely, in- 

 soluble in water. It costs about 2 cents per pound in large ship- 

 ments, and in smaller amounts sells at approximately 4 cents per 

 pound. Borax (Na 2 B 4 O 7 10H 2 O) is prepared from colemanite by 

 treatment with soda ash. It retails at about 10 cents per pound, but 

 can be obtained in 100-pound lots or more in Washington at 5 to 6 

 cents per pound. Borax is readily soluble in water. 



EFFECTS OF BORAX-TREATED MANURE ON PLANTS. 



The chemical analyses and bacterial counts to which references 

 have been made throughout this bulletin do not indicate any perma- 

 nent deleterious effects of the borax on manure. On the contrary, 

 a beneficial effect is suggested. This was especially the case with the 

 chemical results where an increase of ammonia was obtained in all 

 cases and no apparent reduction in the total nitrogen was evident. 

 Nitrites and nitrates were found in several of the open piles where 

 borax had been applied. In order to be certain of the effect of 

 borax-treated manure on plants, extensive experiments have been 

 performed both in the greenhouse and in open plats. The field work 

 was conducted at four points in the South, as well as on the Arling- 

 ton farm, and the pot tests were conducted in the greenhouses of the 

 department at Washington. The following plants were tested: 

 Wheat, tomatoes, peas, beets, radishes, kohl-rabi, oats, corn, cucumber, 

 lettuce, as well as apple seedlings and rosebushes. Such elaborate 

 experiments seem to be necessarv on account of the known toxic 



