Generating gases in syrignesThe linked video tells you pretty much all you need to know, just use table salt and sulfuric acid instead if you're not scared of the stuff.
A much safer way i think would be to make use of desiccants within the syringe which appears to be far more convenient than using plastic bottles or glass flasks and allows you to work with smaller amounts ultimately saving you cash.
H2SO4 is nasty and i could do without using that stuff, plus i cant get it anywhere near as cheap as hydrochloric acid.
The method which i have part tested requires:
2x 50ml syringes with luer locks (anything above this will be fine)
2x luer syringe caps
plastic or rubber tubing that fits the syringes (only need a small length)
some sort of lube, cooking oil will work
Powdered anhydrous magnesium sulphate
Hydrochloric acid >30%
The idea is to lube up the plungers, add some MgSO4 to one of the syringes, and depress the plunger to expel the air, suck up a small amount of acid, screw on the cap and shake the syringe until its filled with gas. With the syringe pointing upwards and away from yourself, remove the cap, attach the tubing and connect both syringes together, depress the gas containing syringe to then fill the empty syringe with relatively dry gas, attach the cap and store until needed.
Then use some sort of solvent safe tubing to inject the gas into the mescaline containing solvent and watch some tasty crystals drop out.
When i was testing this out i only got as far as generating the gas in the syringe and generated far too much.
I added around 20ml of the desiccant to a syringe, sucked up about 5ml of acid, capped it and gave it a good shake. This resulted in far too much gas causing the plunger to shoot out splattering the contents on the wall.
Going to experiment and find out what the optimum amount of acid is, until then i'd recommend to start with 1ml to be safe, and make sure you wear appropriate protection, do it in a well ventilated area, or even better outside, it took a good while for the room to air out and didn't smell too great.