The crude fatty acids turn black with sulphuric acid, as the oil does, and yield a similar substance with nitric acid. It is similar in appearance, but differs in that it melts at about 50 deg. C., and is soluble in glacial acetic acid, which is not the case with the substance from the oil. These fatty acids crystallize on cooling, in a most characteristic and beautiful way, forming wavy circular plates totally unlike any that I have seen before. The above experiments may, I think, be taken as conclusive as to the nature of tea oil and cabbage oil. The former may certainly be considered a useful lubricating agent for the finer kinds of machinery. The work upon wood oil is not yet sufficiently complete to show us the nature of its proximate constituents. I am continuing the examination of this oil. Perhaps I need scarcely add that there is no connection between this "wood oil" and the Gurgun balsam, the product of _Dipterocarpus turbinatus_, which is also known as "wood oil." * * * * * THE OTOSCOPE. Prof. Leon Le Fort has recently presented to the Academy of Medicine, in the name of Dr. Rattel, a new otoscope, which we illustrate herewith. The first person to whom the idea occurred to illuminate the ear was Fabricius d'Acquapendentus (1600). To do this he placed the patient in front of a window in such a way as to cause the luminous rays to enter the external auditory canal. It was he likewise who conceived the idea of placing a light behind a bottle filled with water, and of projecting its concentrated rays into the ear. In 1585 Fabricius de Hilden invented the speculum auris. This instrument was employed by him for the first time under the following circumstances: A girl ten years of age had in playing introduced a small glass ball into her left ear, and four surgeons, called in successively and at different times, had been unable to extract it. Meanwhile the little patient was suffering from an earache that extended over almost the entire head, and that increased at night and especially in cold and damp weather. To these symptoms were added strokes of epilepsy and an atrophy of the left arm. Finally, in November, 1595, De Hilden, being called in, acquainted himself with the cause of the trouble, and decided to remove the foreign body. To do this, he selected, as he tells us, "a well lighted place, caused the solar light to enter the ailing ear, lubricated the sides of the auditory canal with oil of almonds, and introduced his apparatus." Then, passing a scoop with some violence between the side of the auditory canal and the glass ball, he succeeded in extracting the latter. At the beginning of the 17th century, then, physicians had at their disposal all that was necessary for making an examination of the ear, viz.: (1) a luminous source; (2) a means of concentrating the light; and (3) an instrument which, entering the auditory canal, held its sides apart.