DESTROYING STUMPS.

Dominion, Volume 5, Issue 1554, 25 September 1912, Page 10

DESTROYING STUMPS.

USE"OF "SULPHURIC AND NITHIC ,: , ■ ACIDS. . The following paragraph is taken from the "Agricultural Gazette" of New South Wales:"Mr. C. Maud, Enna, Gosford, informs the Department that a neighbouring farmer -has been very successful in destroying stumps with-a mixture of sulphuric and nitric acids. In treating a swamp mahogunv stump," 3ft. 6in. in diameter, 6d. worth of acids were put iu an auger hole, and in five' weeks' time the whole stump and roots had so rotted that they could be knocked to pieces with a hoe. Mr. Maud states that a stump 3ft. in diameter would take about half a pint each of the acids, and a smaller one less. The acids are used'in eqnal quantities,' and nothing is ndded to them. A hole is b'ofcd'-'i'n the stump with a 2-inch auger,' deep enough to hold the quantity of acids to-be. used, and-then one acid is poured in-aud-the other added. The hole is then plugged air-tight; with a wooden plug. iNot more'than one pint of acids (half pint'of each) would be mixed at one time. Mr. Maud asks whether there is any danger in this, and what it is. "Mr. I-. B. Guthrie, chemist of the Department, reports as follows :— "There should be no risk attending the mixing of the above quantities, provided the sulphuric acid is,added to the nitric acid, and ■ not.- vice versart There tiari ft certain amount of risk in mixing nitric and sulphuric acids on account of the lieat' evolved and tho consequent danger of spirting. There is not likely to be any danger in mixing small quantities in this manner,'but with larger quantities the mixture will get very hot on tho' first addition.of.the sulphuric acid, and must be allowed to cool before the remainder is added; otnerwiso tho action will be very violent. Both the acids separately are extremely corrosive, and must not come into contact ■ with the person-or clothing.' With dry wood, nitric'-acid forms into nitro-cellulosc, which is an explosive, but' thero is not much risk of this substance being formed under the conditions. Put the nitric acid in- the hole first, then add tho sulphuric acid."