to impregnate lint
or cotton-wool. Recent work has shown it is too feeble to be relied
upon alone, but where really efficient antiseptics, such as mercuric
chloride and iodide, and carbolic acid, have been already employed,
boracic acid (which, unlike these, is non-poisonous and non-irritant)
may legitimately be used to maintain the aseptic or non-bacterial
condition which they have obtained. Borax taken internally is of some
value in irritability of the bladder, but as a urinary antiseptic it
is now surpassed by several recently introduced drugs, such as
urotropine.

BORING. The operations of deep boring are resorted to for ascertaining
the nature, thickness and extent of the various geological formations
underlying the surface of the earth. Among the purposes for which boring
is specifically employed are: (1) prospecting or searching for mineral
deposits; (2) sinking petroleum, natural gas, artesian or salt wells;
(3) determining the depth below the surface of bed-rock or other firm
substratum, together with the character of the overlying materials,
preparatory to mining or civil engineering operations; (4) carrying on
geological or other scientific explorations.

Prospecting by boring is practised most successfully in the case of
mineral deposits of large area, which are nearly horizontal, or at least
not highly inclined; e.g. deposits of coal, iron, lead and salt. Wide,
flat beds of such minerals may be pierced at any desired number of
points. The depth at which each hole enters the deposit and the
thickness of the mineral itself are readily ascertained, so that a map
may be constructed with some degree of accuracy. Samples of the mineral
are also secured, furnishing data as to the value of the deposit. While
boring is sometimes adopted for prospecting irregular and steeply
inclined mineral deposits of small area, the results are obviously less
trustworthy than under the conditions named above, and may be actually
misleading unless a large number of holes are bored. Incidentally,
bore-holes supply information as to the character and depth of the
valueless depositions of earth or rock overlying the mineral deposit.
Such data assist in deciding upon the appropriate method for, and in
estimating the cost of, sinking shafts or driving tunnels for the
development and exploitation of the deposit. In sinking petroleum wells,
boring serves not only for discovering the oil-bearing strata but also
f