isobutylene and cumene and free radical polymerizable monomers such as styrene acrylic acid methacrylic acid acrylonitrile and other vinyl compounds this list is merely representative as a rule the present solid insoluble materials may find application in any of the monomers or solvents which require stabilization by conventional soluble polymerization inhibitors in a preferred application the inhibitors are used to stabilize lower ethers especially diethyl and diisopropyl ethers in use the solid insoluble stabilizers are placed in intimate contact with the liquid being stabilized this may be done by mixing particles of solid as such with the liquid this may also be done by placing the particles in a mesh or screen bag or compartment with which the liquid is in contact this latter embodiment has the advantage that the particles of inhibitor automaticaly separate from the liquid when desired the amount of solid inhibitor employed will generally be at least as great on a weight basis as the amount of soluble inhibitor employed amounts of from about 1 part per billion basis organic liquid to about 1 basis organic liquid may be employed with amounts from about 10 parts per billion to about 0 1 by weight being preferred the invention will be further illustrated by the following examples which are not intended to limit the invention 39 s scope the procedure of f camps et al tet let 1713 14 1971 was followed to 13 0 g 125 mmoles of macroreticular polystyrene amberlite xe 305 rohm haas and 27 6 g 67 5 mmoles of thallic acetate sesquihydrate tl oac 3 1 5 h 2 o suspended in 200 ml of carbon tetrachloride was added dropwise with stirring 12 8 g 4 1 ml.