No. 2. Bermudez (Venezuela) Asphalt. The action of the water upon this asphalt was noticeable and similar in character to that just described, but it proceeded much more slowly and was far less in amount. For a long time the surface remained black ; later it became brownish. At first there was a slight cracking of the surface, but after ward the surface became wrinkled. In the jars the depth of action was .03 mm. in distilled water, .02 mm. in the surface water, and .01 mm. in the well water.
No. 3. Alcatraz (California) Asphalt, Grade D. There was a slight, but measurable action upon this asphalt. The color changed from black to brown, but the surface remained quite smooth. The depth of action in the jars was .005 mm.
No. 4. Alcatraz Asphalt, Grade XX. This asphalt showed greater action than the preceding, and almost as much as the Bermudez. At the end of two years the surface of the asphalt in the jar was brown and wrinkled. The depth of action was .015 mm. in distilled water, and .010 mm. in the surface water and well water.
No. 5. Alcatraz Maltha, No. 1. The action of the water upon this maltha was confined to a thin film at the surface. The color changed from black to brown, but on drying the brown color almost disappeared.
No. 6. Alcatraz Maltha, No. 2. The action was not quite as strong as in the case of Maltha No. 1.
No. 7. Cuban Asphalt, No. 1. This asphalt had a hard, shining surface, and was exceedingly brittle. There was no apparent action.
No. 8. Cuban Asphalt, No. 2. This asphalt is also very brittle. There was a very slight action at the sur face, with a change in color from black to brown. The depth of the action was too small to be measured.
No. 9. Assyrian Asphalt,* No. 2. There was no ap parent action.
No. 10. Assyrian Asphalt, No. 3. There was no ap parent action.
No. 11. Assyrian Asphalt, No. 4. There was almost no action, though in one case the surface was very slightly browned.
No. 12. Assyrian Asphalt, No. 5. This asphalt was considerably acted upon. The color was decidedly brown, and the surface spongy. The depth of action was .02 mm. in distilled water, and .01 in the surface water. This product is not intended to be used in contact with water.
No. 13. Assyrian Asphalt, No. 6. There was no ap parent action.
No. 14. Assyrian Asphalt, No. 7. There was no ap parent action.
No. 15. Asphaltina. There was a very slight action, but it was too small to be measured.
No. 16. Asphaltina Mixed with Cuban. There was no apparent action.
No. 17. Petroleum Residuum. There was no apparent action.
Table XIX shows the loss from the asphalts after two months' exposure in the jars, obtained by analysis of the supernatant water, as above described. The results are expressed in "grams per square meter of exposed sur face." The figures in the first column represent the total solid matter taken up by the water ; those in the second column,the amount of organic matter volatile at a temperature just sufficient to redden platinum ; those in the third column, the fixed solids.
It will be seen that to a certain extent the amount of soluble matter corresponds with the intensity of the action of the water upon the asphalts. For example, in almost every case the action was greatest in the jars that contained distilled water; and in those jars, also, the largest amounts of soluble matter were taken up by the water. The water over the Trinidad asphalt contained more soluble matter than most of the other samples, and this asphalt was acted upon the most strongly. The cor respondence between action of water and soluble matter was not perfect, however. Assyrian asphalt No. 5 gave up a phenomenally large amount of soluble matter in proportion to the extent of the surface action, while a few of the asphalts that were apparently unacted upon gave up some soluble matter, both organic and mineral.
The analyses of the distilled water made at the end of two years showed results slightly higher than those given in Table XIX.
The organic matter represented by the loss on ignition was asphaltic in character. During ignition it blackened and gave off the characteristic odor. This odor could be detected in the waters of the jars, and was found to cor respond in intensity with the amount of action that had taken place. The fixed solids comprised sodium chloride, carbonates and sulphates of calcium and magnesium, and oxide of iron.
The results of the second series of experiments showed the increase in weight of each sample after exposures of one day, one week, and two months. The greatest in crease of weight was observed in the case of the Trinidad asphalt.