If any apology were required for a somewhat late notice of Dr Sayre's method of rectifying curvature of the spine, it would be found in the fact that among the arts the healing art holds an eminent place, and has special claims on every one's attention. Dr Sayre, an American, has this year visited England to make known his method of curing those malformations of the backbone under which many persons remain cripples for the whole of their life; and now that it is known, the wonder is that it was not thought of before. In carrying out the operation, the patient is lifted from the ground, and suspended by a support under the chin and back of the head: sometimes a support is placed under the armpits, and sometimes the arms are raised. In this position the weight of the pelvis acts on the crook in the spine, and pulls it straight; a bandage dipped in plaster of Paris is then bound round the body; a few iron splints are inserted in the bandage, and as the plaster dries, a mould is formed, which keeps the straightened bones in place. The suspension is now at an end; the patient is found to be an inch or two inches taller than before the operation, and can walk without limping. After a few days, the plaster-mould is cut up each side, to allow of removal for washing the body; but the two halves are quickly replaced and held in position by a bandage. In some instances six months' wearing of the plaster-mould effects a cure, and the patient enjoys an ease and activity never before experienced. This method of cure contrasts favourably with the treatment which keeps the patient supine many weary months. As may be imagined, it succeeds better with children than with adults; but even adults have been cured. A case occurred at Cork, the patient being a woman aged twenty-two, and requiring a little mechanical pulling to assist in the straightening; but it was accomplished, and she walked out of the room two inches taller than she entered it. Mr Hoppe-Seyler, a learned German, has published a paper on Differences of Chemical Structure and of Digestion among Animals, supported by numerous examples, which shew that according to the organism so is the power to form differences of tissue; and he sums up thus: 'Looking at the question broadly, we find that the chemical composition of the tissues and the chemical functions of the organs present undoubted relations to the stages of development, which shew themselves in the zoological system, as well as in the early stages of development of each individual higher organism. These relations deserve further notice and investigation, and are qualified in many respects to prevent and correct errors in the classification of animals. It is generally supposed that the study of development is a purely morphological science, but it also presents a large field for chemical research.' This concluding sentence is significant, and should have serious consideration.