The inconveniences occasioned by the smell of sulphuric ether, the considerable doses required to be given, and its tendency to irritate the bronchial tubes, led Simpson to inquire for and to try other analogous liquids. He was recommended, among others by Dr. Gregory, to try chloroform, discovered by Soubeiran in 1831 and Liebig in 1832, and accurately investigated by Dumas in 1835. He concluded after much labour, and the expenditure of some hundreds of pounds, that chloroform, without the unpleasant smell of ether, produced more rapid effects with a smaller dose, and he very soon began to use it in midwifery and to introduce it to his surgical friends for operations. It was brought before the Edinburgh Medico-Chirurgical Society on the 10th November 1847; and so well-known and favoured did it become that in a very short time Simpson’s Edinburgh chemists were manufacturing 7000 doses a day. Here we might almost stop in this record, but for two things, one the controversies Simpson had as to the impropriety and irreligiousness of removing pain, supposed to be one of the Creator’s ordinances which ought not to be mitigated; and the other, the deaths that began to occur under the administration of chloroform. As to the first, a specimen of the objectors is furnished by a clergyman, who wrote “that chloroform was a decoy of Satan, apparently offering itself to bless woman; but in the end it will harden society, and rob God of the deep earnest cries which arise in time of trouble for help.” Even the relief of pain in surgical operations was held by many to be unwarrantable. But a powerful counter-argument was found, in the much greater ease and certainty of success with which surgeons could now perform their operations when the cries and writhings of the patient were removed. The controversy that ensued, however, would fill a volume, and Simpson in it proved himself, as ever, a hard hitter. For many years scarcely anything but chloroform was used for producing anæsthesia; but gradually numerous unexpected deaths under its administration led many to think that it had too depressing an effect on the action of the heart, in some cases at least, and led to the trial of other agents, including bichloride of methylene, the reintroduction of ether, and nitrous oxide. The two latter are very largely used at present, and so also is a mixture composed of one part by measure of alcohol to two of chloroform and three of ether, also known as the A.C.E. mixture, from the first letters of the three constituents. This is now considered by many to be safer than chloroform. What will be the judgment of future experience we can have no pretensions to decide.