A chemical has recently appeared on the market that is far better than any of those formerly used. The product is Quaternary-O, which in the words of the manufacturer is a "high molecular weight quaternary ammonium surface active agent." Translated, this is a super-detergent with superior wetting action. It is a thick, brownish goo resembling automobile lubrication grease. It dissolves slowly in hot water, but not in cold. The fossils are placed in a saucepan and covered with a solution of Quaternary-O. Several tablespoons of Quaternary-O dissolved in a pint of water is a strong enough solution. The liquid containing the fossils is brought to a rolling boil, and boiling for ten to fifteen minutes cleans most specimens. Longer boiling, up to half an hour for stubborn specimens, does not seem to hurt the fossil despite the slight acidity of the solution. As the liquid boils down, more water should be added.

After the liquid cools, the fossils are ready to be removed. The clear liquid remaining after the solution stands awhile can be poured off and reused almost indefinitely. There is a slight odor during the boiling, but it is not unpleasant. Do not plunge hot fossils into cold water; they might shatter.

Fossils that seem particularly well suited to Quaternary-O cleaning are those from shale, sandstone, or somewhat weathered limestone matrices that are not too thick. Even rather thick matrix can be removed layer by layer if the boiling is combined with scraping to remove the layer of loosened material before the specimen is boiled again. Any fossil that has weathered free of matrix is usually sturdy and will clean well.

The boiling is almost as effective as ultrasonic cleaning in its ability to remove matrix from intricate pores and openings, and to reveal borings in brachiopod shells, pores in blastoids, and surface ornamentation in clams and brachiopods. Such details may not have been visible even after scrupulous cleaning by hand. As with all types of cleaning, a good practice is to try a damaged specimen first to see whether there is any reaction to the Quaternary-O and whether the fossil will withstand bouncing about in the pan under a rolling boil.

The sludge removed from the bottom of the boiling pan can be allowed to settle through several changes of water in a jar. It will contain perfectly cleaned microfossils such as ostracods, conodonts, microcrinoids, fish teeth and bones, and who-knows-what. If fossils from only one locality are boiled at one time, and the sludges are kept separate, the microfossils will not be mixed. Thus they will be a bonus along with well-cleaned fossils.

Quaternary-O is available from K and K Labs, 121 Express Street, Plain-view, N.Y. 11803. The cost is approximately $10.00 a pound, or $2.00 a pound in 40 lb. lots. It may be worthwhile to consolidate orders from a group of collectors to take advantage of the quantity price.

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