Being condemned to submit to a dental operation of unusual severity, the opportunity to experiment was gladly availed of, even at the expense of comfort. One special aggravation of the operation was the prying open of the mouth, in order to build up from the root one of the teeth located farthest back in the mouth. The mouth was not large enough to suit the facile convenience of the dentist, and hence he made use of all the skill and power he possessed to enlarge the cavity, and having stretched it to the utmost, firm wedges held it open, without possibility of protest, for three hours on a stretch; and on these instruments and conditions of torture I had ample opportunity to experiment; so sufficient--for all practical purposes--that I do not feel it necessary to repeat the experiment, even in the interest of scientific investigation. The experiment proved, however, my contention, that even the greatest possible pain is of itself not very severe, and that it requires but a slight diversion to make one forget it, for the time being, entirely. I was able, at any moment of the combined irritation, to concentrate my mind upon some subject or object, and to lose the sense of pain out of my consciousness altogether--and at will. Major General O. O. Howard, U. S. A. (retired) has recently corroborated, to the author, out of his own experience, the possibility of forgetting pain through slight diversion. He lost an arm during the Civil War, and in the process of recovery some of the nerve-ends were not properly cicatrized, so that ever since the wound healed the General has not been free from the sensation of pain, whenever his mind has reverted to it, and yet he is able at any time to forget it by change of thought. In like manner, fear-of-trouble is the major part of all the so-called trouble that is experienced. As intimated in the "definitions," under the caption of "Trouble," there are few real conditions that are very uncomfortable, if apprehension of still more uncomfortable conditions is not imported to exaggerate the existing discomfort. Fear of freezing to death or of drowning may be made very terrible, for instance, whereas the end in freezing and in drowning is known to be so comfortable, and even blissful, that those who are on the point of passing out of life by those means dislike to be called back to life again. The heroism of mothers in the event of child-birth is too well known to call for reference, but there is the greatest difference in the ease or in the discomfort of the condition attending the process, which is largely influenced by the feeling of welcome or the attitude of aversion with which the new-comer is greeted by the mother.