The first cannabis/tobacco vaporizing device ,made it's appearance the year
1560 ce .
Operation[edit]
Hookah cross-section view
A small hookah
The jar at the bottom of the hookah is filled with water sufficient to submerge a few centimeters of the body tube, which is sealed tightly to it. Deeper water will only increase the inhalation force needed to use it. Tobacco or tobacco-free molasses are placed inside the bowl at the top of the hookah. Often the bowl is covered with perforated tin foil or a metal screen and coal placed on top. The foil or screen separates the coal and the tobacco, which minimizes inhalation of coal ash with the smoke and reduces the temperature the tobacco is exposed to, in order to prevent burning the tobacco directly.[citation needed]
When one inhales through the hose, air is pulled through the charcoal and into the bowl holding the tobacco. The hot air, heated by the charcoal vaporizes the tobacco without burning it.[70][verification needed] The vapor is passed down through the body tube that extends into the water in the jar. It bubbles up through the water, losing heat, and fills the top part of the jar, to which the hose is attached. When a smoker inhales from the hose, smoke passes into the lungs, and the change in pressure in the jar pulls more air through the charcoal, continuing the process.
If the hookah has been lit and smoked but has not been inhaled for an extended period, the smoke inside the water jar may be regarded as "stale" and undesirable. Stale smoke may be exhausted through the purge valve, if present. This one-way valve is opened by the positive pressure created from gently blowing into the hose. It will not function on a multiple-hose hookah unless all other hoses are plugged. Sometimes one-way valves are put in the hose sockets to avoid the need to manually plug hoses.
https://en.wikipedia.org/wiki/Hookah
Mistaken by many ,that is a smoking device.
Well if it's well "prepared" and used ,it's not.
It actually vaporizes it's load.
Still ,the heat source used (coal) releases toxic fumes and particles .
Far from ideal.
Cheers.