The success of these agents, especially _ether_ and _chloroform_, in _preventing pain_, is undoubted; nor do they appear to have any other effect, nor to prevent any necessary effort or process of nature, except in a few cases which will be mentioned further on. Many hundred operations of the most severe kind, such as cutting off limbs, removing tumors, stones, and so forth, have been performed while the patients were under the influence of these agents, and without causing them _the slightest pain_; in fact, many remain, during the whole process, in a pleasant dream, and cannot be persuaded, when they wake, that the dreaded operation is over. The same thing has also been observed in hundreds of cases of midwifery, both in natural labor and when instruments have been used. In numerous instances the female has been _put to sleep_, and safely delivered, without knowing or feeling anything whatever, during the whole time; the first intimation that she had become a mother, being the cheering cry of her newborn babe. In some instances, the state of insensibility has been continued for a long time, and during its continuance, the most hazardous operations have been safely performed. So far as can be safely judged, from the limited time during which such means have been used, it appears that there is no danger whatever, from their employment, except when improperly administered, and in certain peculiar conditions of the system; which causes of danger will, of course, be removed by competent experience and knowledge. It is highly encouraging however, to note, though ether and chloroform have both been used so extensively and indiscriminately, both by those who understood their nature and those who did not, that the cases in which they are proved to have done injury, are _not more than two or three_; and in all those that I have heard of, some obvious impropriety had been committed in their use. It should be borne in mind, however, that even if the danger from them was considerable, we might still be justified in their use. It is well known that, in numerous cases, the _fear_ of suffering, beforehand, and its severity while being endured, produce the most serious, and even fatal results. Many a patient has passed safely through the ordinary effects of a painful operation, and yet sunk from the mere effects of _fear_ and physical suffering. Instances have even been known in which a fear of this kind has caused _death_, and frequently it has given a shock from which the patient never fully recovered. There is also, frequently, great danger from the violent efforts and struggles of a person in pain, and many necessary operations are even prevented altogether by them; this is often observed in difficult labors. When insensibility is produced, however, all these causes of difficulty and danger are removed; the patient's _fears_ are quieted, suffering is entirely prevented, and there is no struggling to prevent the necessary assistance.