Lac caninum is not a novelty in remedies. "Dioscorides, Rhasis, Pliny, and Sextus recommended it for the removal of the dead foetus. Sammonicus and Sextus praise it in photophobia and otitis. Pliny claims that it cures ulceration of the internal os. It was considered an antidote to deadly poisons." (Quotation by Hering.) Hering adds that the remedy was revived by Reisig, of New York, who used it successfully in the treatment of diphtheria. After Reisig the remedy was used by Bayard and Swan, to whose indefatigable exertions we owe the present status of this medicine. Swan's potencies were prepared from Reisig's 17th. The provings were made with the 30th and upwards and are published in a little volume by Swan and Berridge. As in the case of Bufo, Castor equi, and other remedies of ancient times, homoeopathy has stepped in to confirm the accuracy of the old observers. In the provings a large number of the symptoms were manifested in the region of the throat, the effects being diagnosed as actual diphtheria in some instances. It is in diphtheria, both as curative and prophylactic that Lac can. has won its greatest fame; and the provings and clinical experience have developed a grand characteristic in this and other affections—an alternation of sides, often very rapid. "Soreness of throat commences with a tickling sensation which causes constant cough then a sensation of a lump on one side, causing constant deglutition this condition entirely ceases, only to commence on the opposite side, and often alternates, again returning to its first condition; these sore throats are very apt to begin and end with the menses." This "alternation of sides" once led me to the cure of an eczematous condition of the eyelids in a child. The child's aunt, who brought her to me, casually remarked that it often left one side entirely and went to the other and then back again. Lac can. cleared it up in a very short time. Rheumatic and other affections having this peculiarity of changing from side to side are very likely to be benefited by Lac can. From diphtheria, with its fetid discharges, it is not a far step to ozaena, and Lac can. has proved itself curative in a number of cases. Corners of mouth and alae nasi cracked. It has cured a case presenting the following characters: Crusts under which grey matter forms. Throat bad, swallowing difficult; mucous follicles swollen, covered with cream-coloured mucus. Nose bad; feared destruction of bones. Bloody pus discharges several times a day. Bones of nose sore to pressure. In addition to the changing sides characteristics Lac can. has: "Inflamed surfaces (of throat) glistening." The same appearance when found on ulcerated surfaces in the skin is a leading indication for Lac can. The mental symptoms are remarkable. One prover had delusions about snakes; imagined she was surrounded by them; was afraid to close her eyes at night for fear of being bitten by a large snake which she imagined was beside the bed. Awoke in the night with a sensation that she was lying on a large snake. After menses, imagined all sorts of things about snakes. These snake-symptoms led to a cure. E. T. Balch (H. P., x. 286) asked for advice in this case: "Maud R., 10, demi-brunette, of healthy parents, one and a half years before fell forward and hurt her chest whilst playing. Nothing was thought of it at the time, but when brought to Dr. Balch she was pale, emaciated, capricious, no desire for play. Sleep disturbed by frightful dreams, during the day piteously begs her mother to take her, she is so afraid. She feels as though snakes were on her back. In response to advice tendered one dose of Lac. can. 50m. was given, dry, and in twenty-four hours the child became more lively and cheerful and very soon all abnormal sensations disappeared. Another mental curiosity which has proved a useful pointer is this: "Imagines he wears some one else's nose." Restlessness, nervousness, and prostration appear in the provings and show the relation of the remedy to diphtheritic paralysis as well as to diphtheria itself. In one prover the symptoms occurred periodically: < in morning of one day and < in afternoon of next. Wandering rheumatic pains. The sensation of lightness or levitation was noticed—seemed to walk on air; not to touch the bed when lying. Cannot bear one part of her body to touch another; must even keep her fingers apart. The symptoms in general were < at night. Cold winds and cold, sharp air <. Cold washing = pain in herpetic eruption. Cold application > pain in upper jaw and teeth; and cold water gave momentary > to sore throat. Pains in ankles, forehead, and upper jaw were > by warmth. Rest and lying down > most symptoms; motion <. Flexion >, extension <. Going up and down stairs = pain in heart. Walking = leucorrhoea, < sores between labia and thighs. Touch < (external throat; breasts, causing sexual excitement). < After sleep. The Schema comprises both caused and cured symptoms; the latter are bracketed or have the name of the disease in which they occurred appended in brackets.