62 British Association for the Advancement of Science. 
In air at rest, temperature 70°, it cooled from 90° to 80° in 5™ 405. 
In water at rest, same temperature.........secceceeeeeeeeeees IM 248, 
It is well known that in swimming it is not the fatigue so much 
as the refrigeration which fixes the limit. This appears from the 
following observation compared with the preceding. 
The instrument agitated in water, cooled from 90° to 80° in 15°. 
In order to ascertain the refrigeration produced by damp clothes, 
Dr. Osborne covered the bulb of the instrument with cotton wool, 
and having placed it at rest in an apartment at 683°, found it to cool 
from 90° to 80° in 10" 148. Placing it in the same circumstances, 
but with the cotton wool slightly damped, it cooled down in 2™ 57%. 
This proportion must be much increased when under the influence 
of the open air. The application of cotton wool to the skin, moist- 
ened with water or an evaporating lotion, he has found the most 
eligible means of cooling the surface in disease, not only on account 
of the constancy with which the refrigeration is maintained, but 
from its being peculiarly agreeable to the feelings of the patient. 
On the Influence of the Artificial Rarefaction or Diminution of At- 
mospheric Pressure in some Diseases, and the Effects of its Con- 
densation or increased Elasticity in others. By Sir JAMES 
Murray. 
The paper was divided into two parts. The first detailed the ge- 
neral principles of the rarefaction of air, and its powers as a reme- 
dial agent on the human body. The second part related to the local 
agency of condensation of air in topical diseases. 
The propositions were submitted, not as remedial means of them- 
selves alone, but as auxiliary to those already in use. It was shown, 
That the ordinary atmospheric pressure sustained by the whole body 
averages 15 tons ;—that by placing a person in an air-tight bath, with 
provision for breathing the ordinary atmosphere, half a ton or a ton 
can be removed without danger : 
That the abstraction of this elastic compression permits the easier 
expansion of the chest, elicits the bleod and animal heat to the sur- 
face of the body, opens the pores of the skin, and restores to the 
surface rashes or eruptions which had been suppressed. 
It was therefore submitted, that an agent capable of producing 
such effects is entitled to consideration in treating certain conditions 
of pectoral diseases; in eliciting internal congestions or inflamma- 
tions from central organs to the surface ; in preventing certain fevers, 
and other complaints arising from obstructions of the cutaneous 
functions; in translating gout and rheumatism from vital organs to 
the limbs ; in restoring a due balance of the circulation, and attract- 
ing the blood into the superficial veins from the deep-seated arteries. 
A case of a patient was detailed, in which congestion of the brain 
was diverted from the head by inclosing one of the lower extremi- 
ties in a rarefying bath, and abstracting about two pounds and a half 
of pressure from each inch of the surface: the influx of the fluids 
was so great, that in two hours the circumference of the limb was 
