A commercially produced pharmaceutical is almost pure. In contrast, the purity of illegal drugs is ofcourse, unspecified: the user may get the supposed drug, a diluted verison of the drug, or an entirely different substance. Every illegal drug has been sold in bogus forms at some point in history. Almost all street cocaine, for example is heavily diluted with other substances. In a study of purported mescaline, ever sample proved to be something else (usually LSD or PCP). It is very easy to pass off cheap pills and powders as a similar-looking drug. Because synthtic drugs dicerted from pharmaceutical sources have the greatest purity, many illegally made synthetics are made to look like them, with fake labels and packaging. Even natural drugs such as psilocybin may be store-bought mushrooms dusted with amphetamine or another cheap stimulant. The low purity of illegal drugs also results from sloppy manufacturing. Illicit labs have little regard for precision, proper storage, or avoiding contamination. The result is the production of chemicals of which drug makers have little knowledge. The user is very lucky if a synthetic illegal drug is 90% pure- and it's purity is more likely to anywhere from 60% down to 10%, or it may contain none of the supposed drug at all. What are the other ingredient, you ask? They can be anything from fillers such as cornstarch and talcum powder, to cheaper substances that mimic the drugs effects, such as local anesthetics, caffeine and strychnine. Drugs are "cut" to increase volume by mixing the pure drug with other, cheaper substances. This is usually done with a sharp knifeor a razor blade, finely chopping and mixing the powders so that it looks like a uniform substance. It is easy to dilute powders in this way, but drugs in hard chunks are more diffcult to combine with other substances without the result being quite obviously a mixture-the chunks have to be broken up to mix them, and even then the final product looks clearly diluted. For this reason, rock-like cocaine is often perferred, and even heavily cut cocaine will be with a few rocks to make it look more authentic. There are many tests of drug purity, ranging from sophisticated laboratory methods to relatively crude appraisals. Some commerical laboratories will provide an accurate and confidential analysis of a drug for a small fee. A very effective home method is to check the melting point of a drug. Using an apparatus called a hot box, a flask of mineral oil is placed over a flame. A thermometer is placed in the oil to measure it's temperature. Suspended in the oil is a test-tube containing a small amount of the drug. When the drug begins to melt, the temperature is noted. Different chemicals melt at very specific temperatures. This procedure is so precise that even the percentage of adulteration can be determined. For example, if about 25% of a sample melts at 187 degrees and the rest melts at 203 degrees, it can be assumed that the sample is 25% cocaine and 75% lactose. Melting points in degrees Celsius Cocaine freebase-98 Lidocaine-127MDMA-148 Mannitol-165 Methamphetamine-170 Heroin-173 Quinine-177 Cocaine hydrochloride (powder)-187 Lactose-203 Vitamine B powder-224 Caffeine-237 PCP-243 Ephedrine-247 Baking Soda-270 Paul Gahlinger, M.D., Ph.D.