sinking of one pound of Bunker "C** oil required two pounds of No. 100 

 sand. The difference may be easily attributed to the differences in 

 the conditions of the tests, as well as to the different grades of oil 

 or sand used. 



According to the recommendations by the Chemical Laboratory (1947), 

 the carbonised sand is sprayed in such a way as to float on the oil 

 slick in sufficient amount to absorb and combine with it, but not to 

 force the sajid below the surface. After sufficient time is allcwed 

 for the sand to absorb the oil, the treated slick is sunk with water 

 frcm a hose. In the laboratory technique, using small amounts of material 

 in finger bowls, there was a tendency to add more sand than probably was 

 needed and the sinking was accomplished in part by added weight of sand. 



The addition of crude oil and carbonised sand has no significant 

 effect on the pH of sea water, which changed from 8,05, before the addition, 

 to 8.08 after the treatment was completed and the oil submerged by spray- 

 ing it with 27 ml. of sand. After 24 hours, the original value of 8.05 

 was restored. All pH measvirements were made with the Beckman potentiometer. 



SELECnON CF BXFERMENTAL ANIMALS 



For our study of the effects of oil slicks and the mixture of oil 

 and carbonised scmd deposited on the bottom as a result of the spraying 

 of these slicks with carbonized semd, we selected such forms that would 

 normally live attached to submerged objects, or on the bottom in estuaries 

 and harbors where this type of pollution is most apt to occur. We chose 

 in particular animals of known economic importance, but also included 

 others which aptly lend themselves to the experimental procedures desired. 

 A good test organism should be available in fairly large nunbers and be 

 hardy enough to svirvive in the laboratory tanks, supplied with running 

 sea water, for a reasonable length of time wi liiout being weakened or 

 losing its responsiveness. In measuring the reaction of the animal to 

 an altered environment, particularly one caused by the addition of a 

 substance that may prove to be inimical to its existence, the criterion 

 of change in a response that is being studied and the criterion of death 

 must be definite and clear. An added advantage may be had if the re- 

 actions of the animal can be automatically recorded or measured, as, for 

 instance, the heart beat, the rate of pimping of water by the gills, the 

 movements of tentacles, etc. After due consideration and several pre- 

 liminary tests, we decided to use the following organisms ; the hydrosoan 

 Tubularia crocea , which grows attached to pilings and docks; the barnacle 

 Balanus balanoides, a very common form growing abundantly on rocks and 

 structures near low tide mark; the embryos of the toad fish Opsanus tau, 

 one of the common bottom-dwelling fishes in harbors and bays which attaches 

 its large eggs to wood, rocks, and other submerged objects; the hard shell 

 clam Venus mercenaria , which inhabits the mud flats; and the oyster Ostrea 

 virginioa, found on rocks and on the bottom in all coastal waters. Of these 



