Archive | P RSS feed for this section

PYROLIGNEOUS ACID

The crude acetic acid liquor obtained by the dry distillation of wood. The acid distillate is neutralized by lime and the calcium acetate thus obtained is distilled with hydrochloric acid, thus yielding the acetic acid as distillate.

Comments are closed

PINE TAR OIL

is a distillate of pine tar which darkens to a reddishbrown colour on keeping. It has a strong tarry and sharp odour, and is a very complex mixture resulting from the destructive distillation of the tar. Its average sp. gr. is 0970; it is soluble in turpentine, and is used in ore concentration by the flotation process.

Comments are closed

POISONS AND ANTIDOTES

Olive oil, emetic or stomachpump, followed by stimulants. Encourage vomiting, then give eggs beaten up in milk. Sodium sulphate or magnesia. Emetic or stomachpump, or purified charcoal powder if swallowed immediately after the poisoning, and keep patient well awake. Chalk and water freely. One of the best emetics is mustardhalf a tablespoonful mixed in half a tumbler of water, and for children one or two teaspoonfuls of ipecacuanha wine every ten minutes. Another good emetic for adults is a teaspoonful of sulphate of alumina.

Comments are closed

PAINTS

Mixtures of whitelead, redlead, zinc oxide, zinc sulphide, lime, barium sulphate, or other mineral bases with boiled linseed oil and turpentine, used to prevent the rusting of iron and for the preservation of wood and other surfaces; also for artistic and decorative purposes. Tests have definitely proved that a paint made with 50 per cent, barytes and 50 per cent, whitelead is more durable as a pigment than pure whitelead paint. A luminous paint of soft greenish glow and great durability is now prepared by incorporating a small proportion of radium salt in a zinc sulphide base, using some good binding material such as nitro cellulose lacquer. Volatile liquids, such as benzene, petrol, turpentine, naphtha, and acetone, are used in paintmaking as thinners or vehicles, and upon evaporation, leave the boiled linseed oil and mineral base on the coated surfaces. The linseed oil absorbs oxygen from the air, and mixed with the base forms a conglomerate solid mass constituting the real paint. Turpentine differs from the other vehicles named, inasmuch as it does not volatilize so quickly, and absorbing oxygen from the air/, forms a skin of oxidized product, thus adding slightly to the weight of the dry paint.

Comments are closed

PANDERMITE

A trade name for calcium borate, used in compounding ceramic frits.

Comments are closed

PROTOCATECHUIC ACID

2CO,OH A crystalline substance soluble in water, made by heating catechol 2 with ammonium carbonate.

Comments are closed

PINCHBECK

An alloy goldlike in appearance consisting of copper alloyed with zinc in varying proportionsabout 3 oz. zinc to i lb. copper or 1 part zinc and 8 parts copper.

Comments are closed

PIPERIDINE

A colourless, liquid amine, smelling something like pepper and of basic character, found in pepper in association with piperic acid as the alkaloid piperine. It boils at 106 degrees C., is soluble in water and alcohol, and yields crystalline salts.

Comments are closed

PTOMAINES

The name given to certain chemical compounds resulting from the action of microorganic lite in the process of putrefaction. They are of a nitrogenous basic nature possibly alkalodaland very poisonous. Several of these substances have been isolated, including a complicated aminated body named ” putrescine” and another named “cadaverine”.

Comments are closed

PHENOLS

A series of bodies, some being liquids and some solids, many of which have antiseptic properties. Ordinary phenol or carbolic acid is the active principle of crude carbolic acid as obtained from coaltar distillation. In the pure state it is a white, poisonous, deliquescent, crystalline substance, ot sp. gr. 108, which melts at 420 C.; is soluble in water at 16 degrees C., and readily soluble in alcohol. It is used in the preparation of amiseptics, disinfectants, dyes, and explosives. Other phenolic bodies are cresol, xylenol, cumenol , carvacrol, and thymol.

Comments are closed