The reason of this is apparently that the negative pressure of the pleural, and partly of the peritoneal, cavity tends to aspirate a liquid relatively thicker, so to speak, than that effused where no such extraneous mechanism is at work (James).
The passage of the fluid is readily effected by negative pressure produced by an ordinary water exhaust-pump.The P Y Y effects of the filtrate are then tested by the methods used in pharmacology.
This will evidently happen when the centre of pressure i' is two-thirds from the inner toe b and one-third from the outer toe c'; and if we displace the centre of pressure still further to the right, the condition that the centre of figure of the diagram shall be vertically under that centre of pressure can only be fulfilled by allowing the point j to cross the base to j" thus giving a negative pressure or tension at the inner toe.
A negative pressure difference indicates a weather pattern dominated by colder continental airstreams.
Vacuum-assisted closure Vacuum-assisted closure (VAC) is a non-invasive technique whereby negative pressure is delivered in a uniform manner to a wound.