HAHNEMANN says Nitric acid is especially indicated for those disposed to diarrhoea. It is most especially effective after Kali carbonicum. Most of the symptoms are relieved after driving in a wagon ; but slight movement, especially after eating, excites heat, sweat and palpitation. It produces great tendency to take cold, and it excites pains in the back and all the limbs. As regards the skin, the sweat-pores are black, and papules are frequent. It disposes to ulcers, and those already existing bleed readily when touched or bound up ; and are the seat of sticking and burning pains, as if from nettles. Itching of the skin is a common symptom, and, after scratch- ing, large blotches appear. Warts itch. Ulcers and caries, resulting from the abuse of Mercury, are relieved by Nitric acid, especially if there be erethism. A characteristic symptom is the sensation of great weakness, sometimes felt early in the morning, as lassitude in the joints and limbs ; sometimes in NITRIC ACID. 321 the afternoon, as weariness, even to trembling, throughout the body. As a consequence, day- sleepiness, even early, soon after getting up. Sleep at night is disturbed ; sometimes by fre- quent waking, sometimes by turning and tossing, sometimes by frightful dreams, and especially often by thirst and necessity to pass water. Abdominal uneasiness and nightmare.