e arsenical
preparations has diminished the importance of mercury in the treatment
of syphilis, but it is still used to supplement the effect of the
injections. The amount of mercury to be given in any case must be
proportioned to the idiosyncrasies of the patient, and it is advisable,
before commencing the treatment, to test his urine and record his
body-weight. The small amount of mercury given at the outset is
gradually increased. If the body-weight falls, or if the gums become
sore and the breath foul, the mercury should be stopped for a time. If
salivation occurs, the drinking of hot water and the taking of hot baths
should be insisted upon, and half-dram doses of the alkaline sulphates
prescribed.

_Methods of Administering Mercury._--(1) _By the Mouth._--This was for
long the most popular method in this country, the preparation usually
employed being grey powder, in pills or tablets, each of which contains
one grain of the powder. Three of these are given daily in the first
instance, and the daily dose is increased to five or even seven grains
till the standard for the individual patient is arrived at. As the grey
powder alone sometimes causes irritation of the bowels, it should be
combined with iron, as in the following formula: Hydrarg. c. cret. gr. 1;
ferri sulph. exsiccat. gr. 1 or 2.

(2) _By Inunction._--Inunction consists in rubbing into the pores of the
skin an ointment composed of equal parts of 20 per cent. oleate of
mercury and lanolin. Every night after a hot bath, a dram of the
ointment (made up by the chemist in paper packets) is rubbed for fifteen
minutes into the skin where it is soft and comparatively free from
hairs. When the patient has been brought under the influence of the
mercury, inunction may be replaced by one of the other methods, of
administering the drug.

(3) _By Intra-muscular Injection._--This consists in introducing the
drug by means of a hypodermic syringe into the substance of the gluteal
muscles. The syringe is made of glass, and has a solid glass piston; the
needle of platino-iridium should be 5 cm. long and of a larger calibre
than the ordinary hypodermic needle. The preparation usually employed
consists of: metallic mercury or calomel 1 dram, lanolin and olive oil
each 2 drams; it must be warmed to allow of its passage through the
needle. Five minims--containing one grain of metallic mercury--represent
a dose, and this is injected into the muscles above and behind the gre