Anaerobic organisms are often overlooked in clinical and biologic laboratories because of the lack of a simple anaerobic medium which can be used just as any aerobic broth without the use of anaerobe jars or other special equipment or technics. It is well known that most clear liquid mediums when heated to drive out the air will be anaerobic for a short time. Whether this period is long enough to allow germination of the spores or growth of the anaerobes present depends on the composition of the medium, the amount of aeration while inoculating and several other factors. For most purposes the period of anaerobiosis obtainable in this manner is not sufficient. To avoid the use of mechanical devices such as the marble seal, special tubes or layers of oil or petrolatum, various substances have been added in attempts to prolong the anaerobiosis and still have a clear liquid medium