Phenol is a product of the distillation of coal tar. It may also be obtained by the distillation of other organic substances, and, finally, may be made artificially- synthetic carbolic acid. Crude phenol is an imperfectly purified article, the result of two distillations. It is a dark-reddish liquid, useful as a disinfectant, and cheap. Further distillations produce pure phenol, which is colorless, crystallizes in needles, and, if absolutely pure, does not absorb water from the air.

If 5 to 10 % of water be added to the melted crystals, phenol will remain clear and not recrystallize on cooling; the further addition of water will cause a separation, phenol going to the bottom as an oily layer, the mixture not becoming clear again until 90 to 95 % of water has been added. The standard solution for ward use is made 1 part in 20 parts of water. The phenol and water should be well mixed, as they do not readily combine. Phenol is freely soluble in glycerin, alcohol, and ether. It sometimes acquires a reddish color on exposure, said to be due to minute quantities of metal, probably copper, contained in traces of the tar products present.

Physiological Effects

Phenol applied locally is antiseptic, irritant, and anaesthetic. In concentrated form it is a severe caustic. The vapor, internally, is stimulant and disinfectant. Taken into the stomach, the acid arrests fermentative changes, and in large doses is a powerful irritant and narcotic poison, acting on the respiratory and vasomotor centres, which it quickly paralyzes. It is rapidly absorbed by the unbroken skin, the subcutaneous tissues, the mucous surfaces, wounds, the respiratory passages, and the stomach, and is excreted by the urine, to which it gives a dark, smoky, or greenish color; also by the saliva, which is increased in quantity.

Phenol is a deodorizer and disinfectant as well as an antiseptic. It is very destructive to low forms of life if used in sufficient strength, but in solutions of a strength which may be safely used externally, as in the dressing of wounds, or applications to skin or membrane, it only prevents the development of germs, and does not kill their spores. Used constantly, as in dressings, even dilute phenol will produce in time a gangrenous condition.

Symptoms Of Poisoning

The first signs of poisoning from the use, either external or internal, of phenol, are: giddiness, tension of the head, and, usually, the dark color of the urine. More serious evidences of danger are: contracted pupils; pallor; embarrassed breathing; a small, slow, feeble pulse; ringing or singing in the ears; and sudden vertigo.

When swallowed in poisonous doses there is at once a hot burning sensation from mouth to stomach, and the symptoms come on immediately. The lips and lining of the mouth are white and hardened; there is nausea, with violent pain and vomiting of frothy mucus; the lips, ears, and eyelids are livid; the pupils contracted and insensible to light. The skin is cold and covered with clammy perspiration; the pulse very feeble and almost always rapid, - 120 - though it has been known to fall to 40 or 50 a minute; the respirations are rapid, irregular, and difficult, sometimes stertorous, sometimes gasping, and the breath has the odor of the acid. Insensibility, coma, and collapse follow quickly in succession, and death may occur within a few minutes from paralysis of the respiration, or, if a very large amount has been taken, from paralysis of the heart. The average time of death is between one and ten hours, and the fatal dose may range from ʒ i. to ℥ ss. (4-16 Gm.)

Treatment Of Poisoning

In the treatment of this poison emetics are not always of use, owing to a paralyzed condition of the stomach, and the stomach-pump should be used, washing out the stomach with 50 % alcohol. The chemical antidotes are sulphate of magnesia or of soda, or syrup of lime, and they should be freely given (℥ iii. of the sulphates have been given) as long as the patient can swallow, or until there is improvement. Lime water and milk in equal parts may be given, and vegetable demulcents - as flaxseed tea, - but no oils or glycerin, as they dissolve the acid and aid its absorption. Atropine is a physiological antagonist, maintaining respiration; and cardiac stimulants may be required, given hypoder-mically.

Phenol is in general use as an antiseptic and disinfectant, though the manner of its employment has been greatly modified and changed in some respects from that of former years. For the practical work of the nurse in cleaning and disinfecting it stands high, and is used in a strength of 1 in 20 or 1 in 40. Articles to be disinfected, viz. soiled clothing, sputum cups, etc., must soak in it for varying lengths of time, according to the nature of the case.

Phenol may be used for clothing, as it does not stain. In the sick-room its strong odor makes it unpleasant to many persons, and this odor may be covered by using oil of peppermint or cinnamon.

Average dose, gr. i.-0.06 Gm., in glycerin or simple syrup - well diluted.

There is a large and constantly increasing group of compounds allied to phenol, called cresols. They are derived from coal tar, and possess strong antiseptic and germicidal powers. As a rule, they are less poisonous than phenol. Among them may be mentioned creolin, lysol, saprol, sozal, chlorphenol, pheno-salyl, aseptol, etc. The well-known Dobell's solution contains phenol, sodium bicarbonate, borax, and glycerin.