From the December 24 1893 Brooklyn Daily Eagle:

“A patient in a Glasgow hospital had received an injury which resulted in melancholia. Though formerly a happy husband and father, he now repeatedly contemplated the murder of his wife and children. There were no phenomena connected in any part of the body by which the injury could be located; but it was discovered by careful close investigation that immediately after the accident for two weeks he had suffered from what is called psychical blindness or mind blindness; that is to say, his physical sight was not at all affected, but his mind was not able to interpret what he saw. That gave Dr. MacEwen the key to the injury. He located on the outside of the skull this convolution known as the angular gyrus, and found, on removing a button of the bone, that a portion of the inner layer of the bone had become detached and was pressing on the brain, one corner of it being embedded in the brain substance. The button of the bone was removed from the brain, and, after removing the splinter, was replaced in its proper position. The man got well, and, though still excitable, lost entirely his homicidal tendencies.”