It is scarcely necessary to give a description of this species which is sufficiently known; we shall content ourselves with indicating the principal characteristics which distinguish it from the other vermin living on the surface of the human body. The louse is of an oval form; flattened, longer than the crab-louse; its head is very small; its thorax is composed of three not very distinct rings; the abdomen is all of one piece, rounded off on the sides; it is ash-colored, whereas the crab-louse is entirely white. The lice which have been made use of in our provings, were taken from the head of a healthy child of five years.

Even before undertaking this experiment we expected to derive from it important results. We entertained the belief that nature pointed out to us the louse as a specific for the hereditary psora, in which belief we were strengthened by the fact that psorin develops the lice-malady in healthy persons. And we are now prepared to affirm that we have found the louse one of the most useful agents in diseases of children. We offer the following pathogenesis with a sincere pleasure which none but those who devote themselves to such patient investigations, can appreciate.


MORAL AND MENTAL: 1. Depression of spirits. Dullness of feeling. Merry in the evening. Very merry. 5. Irascible. Sad without cause. Sensation as if raised off the ground by the hair. She is waked in the night by an attack of dizziness, and inability to open the eyes. Dizziness while walking; the cerebellum feels compressed, with beating and an acute pain on rising in the morning.

HEAD.: 10. Frontal headache. Headache at intervals, and abating all at once. Headache in the evening. Heaviness of the head. Dullness of the head, on rising, with beating in the right temple. 15. Heaviness at the vertex. Violent headache, with dizziness and nausea, in the forenoon. Violent headache, worse on stooping. Headache, with nausea, when walking. Violent headache, and darting in the forehead, when walking. 20. Dull pain in the head, on rising from bed. Headache and pressure at the nasal eminence. Lancinations in the forehead. Dartings in the forehead. Dartings in the right parietal bone. 25. Intermittent dartings in the head, worse when stooping. Heat about the head. Itching of the hairy scalp, in front. Contraction of the hairy scalp. Itching of the left temple. 30. Itching of the hairy scalp. Shuddering over the left side of the hairy scalp. °Falling of the hair.

FACE: Dark complexion. Warmth of the face, afternoon. 35. Itching of the beard. The face is red and bloated. Sweat in the face. Scarlet-redness of the face. To avoid unnecessary repetition, the natural order of the symptoms has been left out, it being nearly the same as Hahnemann's arrangement. Ed.

Itching at the right lower part of the face. 40. Heat in the face. Tingling pain in the right cheek. Itching of the face and hairy scalp. The left cheek is swollen.

NOSE: Tickling and prickling at the left wing of the nose. 45. Inflammation of the nasal fosse . Dartings in the root of the nose. Itching of the tip of the nose.

EARS: Itching in the left ear, evening. Buzzing in the ears. 50. Hot ears. Itching of the right ear. Whizzing in the ears, when whistling. Cracking in the right ear, when eating.

EYES: Itching of the left eyelid. 55. Rings around the eyes. Dilatation of the pupils. Smarting of the eyes as from weeping. The eyes feel weary, are red and smart. Sensation as of sand in the eyes. 60. Smarting around the eyes.

TEETH: The lower jaw feels tired, as from chewing too much. Darlings in the right upper molares.

MOUTH: The lips are black and cracked. Dry, swollen and red lips. 65. Burning and prickling on the border of the tongue, which is red and cracked.

GASTRIC: Hunger, with inability to swallow; the pharynx seems to contract, followed by fainting and desire to vomit, at noon. Aversion to food. Constant nausea in the evening. Difficult digestion, with contraction of the stomach. 70. Colic and diarrhoea after dinner.

THROAT: Sore throat, getting worse until evening. Scraping in the throat. Sore throat every evening. Transitory choking, especially after supper. 75. Dryness of the throat. Scraping at the tonsils, when swallowing. Sore throat, with constriction of the pharynx. Constant swallowing of saliva.

STOMACH &c.: Stomach-ache, and dartings in the umbilical region. 80. Violent colic. Slight colic.

STOOL: Soft stool, in the evening. Diarrhoea evening and next morning. Hard and scanty stool.

URINARY, GENITAL, &c.: 85. Frequent and copious discharge of a watery, yellow-greenish urine. Red urine. Yellow, clear urine. Frequent and copious micturition. Continual erection, without desire. 90. Leucorrhoea. Shifting pain in the uterus, in the evening. Painful stitch in the uterus. Painful dartings, heat and itching in the uterus.

BRONCHIAL, CHEST: Thirst with hoarseness, towards evening. 95. Dry and convulsive cough. Numbness while drawing breath. Pain in the breasts, when drawing breath. Pain in the chest, worse when touched. Oppression on the chest, in the evening.

BACK: 100. Tickling at the nape of the neck and between the shoulders. Itching of the nape of the neck and back. Frequent pain in the loins, when standing. Itching of the back.

EXTREMITIES: Bruising pain on the shoulders and arms. 105. Darting at the arms. Itching of the forearm, in the evening. Pain in the bend of the right arm. Itching of the forearm, in the evening. Tickling at the left wrist. 110. Tickling at the wrists. Darting in the back of the left hand. Itching at the backs of the hands. Itching of the back of the hand, with redness and swelling of the veins. Tremor of the hands. 115. Darting and itching at the first phalanx of the middle-finger. Tingling in the tips of the middle and index fingers. Itching at the ring-finger. Itching of first phalanx of right index-finger. Redness and itching at the right hip. 120. Itching as from nettles in the bend of the thigh. The skin on the left thigh peels off. Weakness of the lower limbs. The knee and upper portion of the left lower limb feel tired. Violent lancination above the left knee-pan. 125. Beating above the left knee-pan. Weariness of the knees, especially the left, in the evening. Intense itching at the right instep. Cold sweat at the feet, followed by excessive coldness, in the evening. Ganglion under the foot, hard, swollen, and painful when walking.

SLEEP, FEVER: 130. Yawning. Drowsy. Uneasy sleep. Restless night. Frequent waking. 135. Dreams about a mob, then amorous dreams with an emission. Confused dreams about being pursued. He dreams that he is dissecting one of his friends. He dreams that he sees people skate on the Seine, in summer. She dreams that she sees acquaintances walk on water. 140. She dreams that she is sick in a dirty hospital, full of vermin; water flows from her mouth. Dream about large-lice. She dreams that she sees a large, black figure flying to the clouds. He dreams that he is to die in a prison, whence he escapes by crawling out. Shuddering all over, eight or ten times in succession. 145. Shuddering in the evening. Shuddering and twitching. Fever.

CUTANEOUS: Pimples in the face, on the forehead, temples, chin, &c., vesicular with a black point in the center. Miliary pimples at the nape of the neck, on a red base. 150. Red pimples on the hands, passing off soon. Red, inflamed pimples on the temples, shoulders, arms, legs. Inflamed pimples on the back, red all around, white in the middle, with a black point in the center. Red inflamed pimples in the face, evening. Smarting pimples on the back, white at their tips. 155. Red inflamed pimples on the left shoulder and arm. White blotches above the left breast. A number of small pimples on the left knee, black at the center. Small red pimples on the feet, on taking them out of the warm water. Red pimples on the shoulders. 160. Small red pimples and itching on the right calf. Red pimples with a black point in the middle, on the right side of the neck. Miliary pimples on the calves, with itching. Miliary eruption at the inside of the thighs, with itching. Former pimples at the nape of the neck reappear. 165. Miliary pimples at the inside of the arms. White pimples on the forehead.

GENERAL: Increase of physical strength. Swelling of the breasts, face, and then of the whole body. Itching all over. 170. Face, hands and feet look red. Tickling all over. Starting when sitting or lying in the evening. Prickling all over, the whole day. Prickling all over, especially at the front part of the thigh. 175. Weariness, dizziness, faint feeling. Shivering, heat and dryness of the extremities. Itching of the skin. Heaviness. Itching here and there, at night.