56 



These oils were synthesized so that the several fractions were 

 added or subtracted in the proportions in which they occurred in the 

 whole oil, which were the following: 



Fraction 210*C-235C 10% 



Fraction 235C-315C 40% 



Fraction 315C-355C 23% 



Residue above 355C 27% 



In view of the difficulties incident to obtaining clear-cut separa- 

 tions by fractional distillation, and consequently to obtaining clearly 

 marked differences in inhibitive or destructive effects upon living or- 

 ganisms, it was felt that the doubling of effect gained by both adding 

 and subtracting the required fraction in each case to the whole oil 

 might so increase the decisiveness of this general method as to make 

 it yield useful results. A piece of untreated wood was attached as a 

 bait to each of those treated and a set of eight specimens so prepared 

 was placed in a rack. Racks containing test pieces of each of the six- 

 teen different treatments are now in place at the following stations 

 in the Bay: San Francisco Pier No. 7, Southern Pacific Oakland Pier, 

 Mare Island, and Crockett. An analysis of the oil from each of the 

 runs has been made, as well as of that extracted from one of the test 

 pieces after treatment. Similar extractions will be made of the oil 

 of each of the test pieces, as they are removed from time to time. 



In addition to the rough indication of the relative value of the frac- 

 tions of creosote, and possible guidance in respect to creosote fortifica- 

 tion, which it seems legitimate to hope for from this series of experi- 

 ments, it has already proved of much value in furnishing information 

 for the guidance of the more carefully controlled series of experiments 

 indicated under schedules 2 and 3. 



In respect to schedule 1, &, this Committee in the cooperation with 

 the Forest Products Laboratory will be expected to give specific at- 

 tention to the tar bases, endeavoring to develop for them more accur- 

 ate methods of analysis than are now available, as well as preparing 

 four specific bases and determining their solubility in water. Toxicity 

 tests will be carried on, in conjunction, by the Biological and Chemical 

 sub-committees, on various creosote constituents with reference to ma- 

 rine borers. In addition to their direct value in the study of marine 

 protection, these tests will afford a valuable comparison between the 

 toxicities of the materials tested, on marine borers and fungi, respec- 

 tively. 



Schedules 2 and 3. The tests under these schedules are kept under 

 much more careful control than are those of schedule 1, a. This series 

 of experiments should show what constituents of creosote become fixed 

 in wood, what are not fixed, what vaporize out and what dissolve 

 away. The chemical constitution of the wood will also be studied, as 



