158 EXPEESSION OF SUFFERING: CHAP. YJ. guarding it against the rush of blood then occurring, the conjunctiva becomes suddenly filled with blood, and the eyelids everted." Not only are the muscles round the eyes strongly contracted, as Sir C. Bell states and as I have often ob- served, during screaming, loud laughter, coughing, and sneezing,. but during several other analogous actions. A man contracts these muscles when he violently blows his nose. I asked one of my boys to shout as loudly as he possibly could, and as soon as he began, he firmly contracted his orbicular muscles; I observed this repeat- edly, and on asking him why he had every time so firmly closed his eyes, I found that he was quite unaware of the fact: he had acted instinctively or unconsciously. It is not necessary, in order to lead to the contrac- tion of these muscles, that air should actually be expelled from the chest; it suffices that the muscles of the chest and abdomen should contract with great force, whilst by the closure of the glottis no air escapes. In violent vomiting or retching the diaphragm is made to descend by the chest being filled with air; it is then held in this position by the closure of the glottis, " as well as by the contraction of its own fibres." 13 The abdominal mus- cles now contract strongly upon the stomach, its proper muscles likewise contracting, and the contents are thus ejected. During each effort of vomiting " the head be- comes greatly congested, so that the features are red and swollen, and the large veins of the face and temples visi- bly dilated." At the same time, as I know from observa- tion, the muscles round the eyes are strongly contracted. This is likewise the case when the abdominal muscles 18 See Dr. Brinton's account of the act of vomiting-, in Todd's Cyclop, of Anatomy and Physiology, 1859, vol. v. Supplement, p. 318.