Several valuable contributions have lately been made to our knowledge of the effects of thyroid feeding, more especially in the treatment of insanity, not however the less valuable as a guide to its probable benefit in idiocy. I wish more especially to allude to the researches of Dr. Lewis C. Bruce, at the Royal Asylum, Edinburgh, as reported in the "Journal of Mental Science" for January and October, 1895. There is much in the above essay that I could profitably comment upon, but I will content myself with saying that the outcome of these researches, which intimately concern the treatment of idiocy, is that Dr. Bruce has established the fact that thyroid feeding acts as a direct cerebral stimulant, which he thinks "may prove advantageous in cases where the higher cortical cells remain in an anergic condition." Dr. Bruce mentions the case of a patient who had not spoken for several months; one day, during the administration of the thyroid extract, he suddenly began to talk, and soon became quite communicative. Whilst these pages are passing through the press, M. Auguste Voisin, Physician to La Salpêtrière, has had the courtesy to send me detailed particulars of a case of insanity in which the success of the thyroid treatment was phenomenal. The patient was a female, aged 25, and her mental derangement assumed the form of religious monomania, insomnia, and aural hallucinations; there was great emaciation, dryness of the skin, and cold extremities.[44] No benefit having resulted from six months' treatment, including hypnotism, M. Voisin determined to try the subcutaneous injection of sterilised thyroid juice. After a few weeks of this treatment, a notable amelioration was observed; shortly afterwards all her unfavourable symptoms disappeared, and she was discharged cured. One of the most interesting features in this case is the result of the analysis of the blood, as to its corpuscular richness. Before thyroid treatment was commenced, the number of corpuscles was only 2,225,000 per cubic millimetre; after the cure by the thyroid juice, the number was more than doubled, being 4,774,000 per cubic millimetre. In Dr. Lewis Bruce's cases, to which I have already referred, the result was the reverse of that observed by M. Voisin; for in the eight uncomplicated cases recorded by Dr. Bruce, with one exception, there was in all of them a diminution in the number of red corpuscles.