Koessler's theoretical initial dose of rag weed extract is one drop of the weakest dilution that will just redden the conjunctiva. As he finds rag weed more toxic than the English timothy, his actual first dose is one-half of this theoretical dose. The actual first dose will vary from one drop of a 1 to 1,000,000 to one drop of a 1 to 20,000 dilution, the smaller of which he estimates to contain of pollen protein one one-hundredth part of a millionth of a gramme or .000,000,01 gramme. Shade of Samuel Hahnemann, the first and greatest homoeopath! And they drove you out of Leipzig into poverty and exile for teaching that in using drugs that are similar to the disease there is serious danger of aggravating the disease; that the dose must be extremely small; and that disease so sensitized the patient that a dose so small as to be inappreciable in health becomes active in disease! The smaller doses of pollen extract are given every three or four days and increased as rapidly as possible, judging the increasing tolerance or resistance by a diminishing eye or skin reaction. With larger doses, the interval is longer, a week or ten days. The pioneer, Noon, and all workers since, warn against increasing the dose too fast, for the reactive power of the patient is easily exhausted, his resistance lowered and he may be left more sensitive than before. =Dangers of Pollen Injections.= Treatment by pollen injection is beset with dangers for the unlucky patient. It has been noted how Dunbar nearly killed his first patient by injecting the serum of the horse that had been immunized to pollen. All experimenters, without exception, say that the injection of pollen extract is attended with danger to the patient, danger of anaphylactic shock, and warn against the use of any but the most infinitesimal doses. The hay fever patient is a human being who, in some way, has been sensitized to pollen. He is in a state of exquisite anaphylaxis and a dose of pollen injected into his blood may kill him in twenty minutes. Goodale reports shock (faintness, nausea, vomiting) in two patients following the mere rubbing of a drop of pollen extract into a scratch on the skin. Evidently the scratch was too deep and the pollen poison was absorbed rapidly into the blood instead of being stopped by the deep epithelia. I have seen a similar absorption and general reaction in children after a skin test with tuberculin, when the tuberculin entered the blood through too deep a scratch.