FORMULi^:. 125 
(56) Powdered cantharides (Spanish fly) ... i oz. 
Oil of turpentine ... ... 2 ozs. 
Methylated spirit ... ... i pt. 
Mix and allow to digest for a fortnight, occasionally stirring, then strain. 
Never to he applied to the loins. Useful blister. 
Caustics are corrosive applications which by chemical action 
destroy tissues to which they are applied and are used in foul 
ulcerated surfaces, spreading inflammations, or to keep down proud 
flesh :— 
[a) Strong caustics. 
(57) Hot iron, rarely used on elephants. 
(58) Nitrate of silver (lunar caustic) — used in pencil as a solid. 
OR 
Zinc chloride. Caution must be exercised in its use as it is a 
very strong caustic. 
The affected tissues are gently rubbed with the stick, which must like other 
solid caustics be held in paper or a caustic-holder. 
(59) Sulphate of copper (blue-stone) — similarly applied. 
(60) Carbolic acid ... ... i part. 
Water ... ... ... 3 parts. 
{b) Milder 
(61) Nitrate of silver ... 
Water 
(62) Sulphate of copper 
Water 
(63) Chloride of zinc ... 
Water 
caustics. 
... 5 to isgrs. 
I oz. 
... 10 to 30 gis. 
... I oz. 
... I to 4 grs. 
... I oz. 
Dusting powders are dry applications used to protect raw surfaces 
and reduce discharges. The drugs are generally mixed with preci- 
pitated chalk, starch, or fine flour : — 
(64) Iodoform ... ... ... i part. 
Starch ... ... ... 3 parts. 
(65) Alum (powdered) ... ... i dr. 
Charcoal ... ... ... 3 drs. 
Chalk 
... I oz. 
Especially used when there is a foul odour. 
