452 RELATIVE ADVANTAGES OF ETHER AND CHLOROFORM. 
oil of vitriol chamber, bv effecting their conversion into 
ammonia. This is done by passing the escaping gases, 
mixed with steam, over heated charcoal, and then into dilute 
sulphuric acid, by which sulphate of ammonia is obtained. 
The following is Mr. Williams’s description of the arrange¬ 
ment he employs, and which has been tried on a large scale 
at the Pontardawe Vitriol Works. 
The apparatus fitted up was of the following description : 
C£ A furnace was built above the exit tube of one of their 
vitriol chambers, and a brick gas retort, about fourteen inches 
in diameter, eight feet long, and open at both ends, was 
passed through its whole length. The retort was filled with 
charcoal, and kept at a red heat; the exit tube of the 
chamber, and a steam-jet to supply the hydrogen, were 
attached to one end, whilst to the other end was fixed an 
upright leaden cylinder, filled with coke, and moistened 
with diluted sulphuric acid. On passing the waste gases 
and steam through the retort containing red-hot charcoal, 
both were decomposed, the oxygen of each uniting with the 
charcoal to form carbonic acid ; the nitrogen and hvdrogen 
combining to form ammonia; then together, probably form¬ 
ing carbonate of ammonia, which was again decomposed by 
the diluted sulphuric acid, the sulphate of ammonia being 
found remaining in solution. This solution was then evapo¬ 
rated, and in July, 1857, I first had the pleasure of obtain¬ 
ing anv quantity of crystals of sulphate of ammonia, by 
this process, from a vitriol chamber in actual work.” 
Mr. Williams does not intend to make this process the 
subject of a patent. 
THE RELATIVE ADVANTAGES OE ETHER AND 
CHLOROFORM. 
At the last sitting of the Imperial Society of Medicine of 
Lyons, the important question of the relative advantages of 
ether and chloroform as anaesthetics was fully discussed. 
Dr. Barrier stated that, to his knowledge, there were only 
three well authenticated cases in which ether had caused 
death, and that even in those there were some extenuating 
circumstances. The deaths caused by chloroform, on the 
contrary, were numerous. If, therefore, ether was slower 
in its action, and more disagreeable in its effect, it was, on 
the other hand, infinitely less dangerous. Dr. Petrequin, 
following on the same side, drew a parallel between the 
means possessed by science for counteracting the dangerous 
