Heat 5 to 10 grams of the sample in a platinum dish of from 50 to 100
cc. capacity at 100° C. until the water is expelled, and add a few drops
of pure olive oil and heat slowly over a flame until swelling ceases.
Then place the dish in a muffle and heat at low redness until a white
ash is obtained. Add water to the ash, in the platinum dish, heat nearly
to boiling, filter through ash-free filter paper, and wash with hot
water until the combined filtrate and washings measure to about 60 cc.
Return the filter and contents to the platinum dish, carefully ignite,
cool and weigh. Compute percentages of water-insoluble ash and
water-soluble ash.