This is one of the most efficient members of this group. It is an active poison, but, as it is returned with the contents of the stomach, no danger attends its administration. It does not act so speedily as copper and zinc. It produces very little nausea, but, when the action begins, the effects are suddenly experienced, and are powerful, without leaving after-depression and sickness. It is not so well adapted to the treatment of narcotic poisoning as the copper and zinc sulphates, but it is the most desirable emetic in the treatment of croup. It was formerly much prescribed in this disease as an emetic, but it fell out of fashion until revived recently by Dr. Fordyce Barker. The author's experience in its use is, in the main, in accord with the much more extended experience of Dr. Barker.

Administration

As the yellow subsulphate of mercury has but little taste, it is easily administered to children. It should be prescribed in the form of powder, rubbed up with sugar of milk. The dose varies from two to five grains. Dr. Barker makes the useful suggestion that powders of this preparation, labeled "croup-powders," should be kept in every household, the children of which have a tendency to attacks of croup. It should be given when the first symptoms manifest themselves, and its repetition will be governed by the state of the breathing.