Dr. Vorster (“Allgemeine Zeitschrift für Psychiatrie,” L. Band, 3 and 4 Heft.) details his experiments on the quantity of hæmoglobin and the specific gravity of the blood of the insane. He refers to the previous experiments of Macphail, Smyth, and Winkler, with which his own results are in general agreement. He observes it has been found in ordinary medicine that the appearance of the patient affords no criterion as to the amount of hæmoglobin in the blood. Schmalz found that there was a parallel relation between the quantity of haemoglobin and the specific gravity of the blood, though not between the specific gravity and the number of the blood corpuscles. Dr. Vorster's experiments were made upon 128 patients, 104 of whom were males and 24 females. He considers the normal specific gravity of the blood to range from 1,055 to 1,062 for males, and from 1,051 to 1,058 for females. Anything under 90 per cent, of the hæmoglobin in males or 85 per cent, in females he holds to be pathological. Vorster's method of research allowed him to experiment on a small quantity of blood.