I don't know for sure, but I would think breaking down the elements of the "ingredients" for a blend is why (if any are solid. Meth has some nasty ingredients-
Psuedoephedrine (E)- yup the stuff in Sudafed- why anything sold with the ingredient is sold behind the counters, Iodine crystals, Red Phosphorus (RP is made from the strike pad on a match book. NOT the matches themselves but the pad it is striked on.) Colemans Fuel, Muriatic Acid (HCl), Acetone, Methanol, Lye
GROSS! Why in the hell would someone want to put this stuff in their bodies?
Something interesting I read- Be careful of using the coffee pots in hotel rooms- apparently they are great sources of heat to produce meth...
http://www.kk.org/streetuse/archives/2007/02/coffee_pot_mini_meth_lab.php