Nitric acid as a chemical substance need scarcely be explained to you, as you know its properties so well. I, therefore, pass on to consider its use as a medicine. You know its effects on the tissues, staining the skin a dark yellowish-brown. It is a highly corrosive acid, eating into the flesh. Hence it has been used for the removal of warts, tumors, ulcers, and exuberant granulations.
It acts very powerfully on the mucous membranes, and has a particular affinity for the outlets of mucous surfaces where skin and mucous membrane join. Hence you will find its symptoms about the mouth, lips, nostrils, meatus urinarius, and anus; in fact wherever skin and mucous membrane come together, there has Nitric acid a prominent action.
As an illustration, we find it useful in stomacace or ulceration of the mouth. Now, keeping up the character of the drug, this stomacace will present its most violent symptoms about the lips. There will be blisters and vesicles on and around the lips in connection with the sore-mouth. Ptyalism will be present, particularly in cases that have been abused by mercury. So, too, you will find that the diarrhoea is associated with sorenes and rawness of the anus. Even fissures may be present, as I have already said.
The characteristic discharges produced by Nitric acid are offensive, thin and excoriating, and, if purulent, are of a dirty yellowish-green color, and not at all laudable.
The ulcers calling for Nitric acid are offensive and characteristically irregular in outline, and tend to dip deeply. That is a sufficient distinction from the ordinary preparation of Mercurius, which produces a superficial flat ulcer. These ulcers of Nitric acid are very apt to be filled with profuse exuberant granulations. They bleed readily from the slightest touch. Even the dressing that you apply makes the ulcer bleed. The pains are of a sticking character, as if splinters were sticking into the affected parts. They are often associated with burning pains. The ulcers are worse from the application of cold water. Nitric acid is particularly indicated in syphilitic ulcers after abuse of mercury, and also in those of a scrofulous character after CALCAREA has failed.
Another evidence of the offensiveness of the exhalations and secretions in Nitric acid is found in the urine, which has a strong odor, very much like that of the horse. It probably contains an excess of hippuric acid. This symptom is most highly developed in BENZOIC ACID. So characteristic is it in that drug that you will find it curing in a great variety of diseases when that symptom is present.
The stools, too, show the putridity of Nitric acid. They are very offensive, and are green in color, and in children contain lumps of casein. They are also slimy from excess of mucus secretion and are associated with much straining; the tenesmus here closely allies it to Mercurius. At other times, particularly in scrofulous children, the stools are pale from deficiency of bile, and pasty and sour as well as offensive.
Nitric acid affects the mucous membranes, producing catarrhs. We find it indicated in coryza, particularly when it is associated with some malignant disease, as scarlatina or diphtheria. In nasal diphtheria, Nitric acid is one of the chief remedies. The discharge from the nose is watery and very offensive, excoriating every part which it touches. If you examine the nose, you will find that there is a well-developed white deposit there. Another symptom which is very characteristic as accompanying these conditions, is intermittent pulse. If the membrane is also in the throat, you will have foetid odor from the throat too. The child will complain of a feeling as though there was a splinter sticking in the throat. This is a general characteristic of Nitric acid, a sensation as of a fish-bone, splinter, or piece of glass sticking in the affected part. This runs all through the symptomatology of the remedy. You find it in the ulcers, and you find it in the rectum associated with the fistulae and piles, and you find it here in the throat.
Nitric acid is here very similar to its complement, ARUM TRIPHYLLUM, which like Nitric acid causes this excoriating discharge from the nose making the lips sore; the corners of the mouth crack, the child cannot open its mouth on account of the soreness.
Another remedy is MURIATIC ACID, which has thin excoriating discharge from the nose, intermittent pulse and loss of appetite.
Another effect of Nitric acid, and one, too, in which it has no superior, is its use to remove the bad effects of mercury. The particular symptoms which call for it in this condition are these : Irritability, restlessness and mental anxiety. This irritability amounts to cursing and swearing. There are also periosteal pains, ophthalmia, inflammation or ulceration of the cornea, with tendency of the ulcers to perforate, hardness of hearing from catarrh of the middle ear and Eustachian tube, ptyalism, ulcers in the throat, caries of bones, particularly of the mastoid process of the temporal bone, dysentery, etc.
It is particularly adapted to secondary more than to primary syphilis, and more especially adapted to secondary syphilis after the abuse of mercury. Chancres have even returned and are phagedenic. There is great soreness in the bones at night, particularly in the bones of the head and along the shins, and this is worse from every change in the weather. On a damp day, he will have a boring pain in the bones. Ulcers appear in the throat or on the surface of the body, and these are characteristically irregular in outline. Warts develop, and these are almost always more or less pediculated. There are yellowish-brown spots or copper-colored spots all over the body. There is great debility with sweat and exhaustion.
When mercury has been abused, HEPAR is probably the best antidote we have. When mercurialization is conjoined with syphilis, Nitric acid is the preferable remedy.
Nitric acid may be needed in the treatment of phthisis. There are sudden rush of blood to the chest, and decided hectic fever, which indicates ulceration of the lungs from breaking down of tubercles. The chest is extremely sore to the touch. The patient suffers from frequent haemorrhages from the lungs, the blood being bright red and profuse. There is great dyspnoea, so that the patient cannot talk without getting out of breath. There are also morning hoarseness, exhausting phthisical diarrhoea, worse in the morning, and sharp stitches through the right chest to the scapula. The pulse is intermittent. The least attempt at exertion causes palpitation of the heart and dyspnoea. The sweat comes particularly at night and towards morning and exhausts the patient very much. The skin is apt to be cold towards morning. He is chilly on getting into bed. Heat comes in flashes, or it is only in the hands and feet.. The skin is of a tickling character and seems to annoy him all night. You hear, on examination, loud rales all through the chest, and the expectoration is offensive, bloody and decidedly purulent, and of a dirty green color, not being yellowish-green and laudable as you find under LYCOPODIUM and PULSATILLA. Sometimes the cough is loose and rattling in character. The patient is usually of thin build with dark hair and eyes.
Nitric acid is very often indicated in phthisis after CALCAREA OSTREARUM or KALI CARB. Calcarea is especially suited to leucophlegmatic patients. The face is pale and sallow. There is soreness of the chest which is very much aggravated by touch or pressure. The cough is loose and rattling. Diarrhoea, if present, is worse in the evening. Hoarseness, though persistent, is painless. When, however, the Calcarea condition has run into the acid debility, Nitric acid is one of the very best remedies to follow. It does not often cure but it relieves and prolongs life for years.
Still another application that we may make of Nitric acid is in typhoid fever, particularly in the ulcerative stage, that is when Peyer's patches have begun to ulcerate. You will find the patient greatly exhausted. The characteristic indications for Nitric acid are these : Stools are green, slimy and offensive, and sometimes purulent, the pus coming from these ulcers, and there is profuse bright red haemorrhage from the bowels, with fainting on the slightest motion. The tongue is either white and studded with vesicles or little sore spots, or it is brownish and dry. We have well-marked pneumonic complications. There seems to be threatening paralysis of the lungs, which you know is by no means an uncommon thing in typhoid fever. This incipient paralysis of the lungs is expressed by loud rattling of mucus in the lungs. The pulse in such cases, ypu will find to be intermitting at every third beat.
Now do not forget MOSCHUS, PHOSPHORUS, ANTIMONIUM TART., ARSENICUM and CUPRUM and other remedies that I have mentioned in this connection.
In haemorrhage from the bowels during typhoid, you may also remember ALURNEN, which is useful when there are large clots passed.
ARSENICUM is called for in this haemorrhage from the bowels when the flow consists of dark watery blood, and is associated with anxiety and restlessness.
We find HAMAMELIS indicated when there is a dark venous flow, without anxiety. Sometimes, the blood is dark and pitch-like.
Still another remedy is LEPTANDRA, which is useful in typhoid fever with symptoms of a bilious character, when the stools consist of black blood, looking like pitch.