Salinity . As described by Knudsen (1901). 

 Electrometric end points were used after 

 August 1951. 



Inorganic phosphorus . By the method of 

 Robinson and Thompson (1948), except that 

 a Fisher electrophotometer was used to 

 measure color intensity. 



Total phosphorus . By the method of Harvey 

 (1948), except that the Fisher AC electro- 

 photometer was used to measure color 

 intensity. 



Nitrate-nitrite nitrogen , 

 of Marvin (1955). 



By the method 



Protein (tyrosine and tyrosine-tryptophan 

 index ). The values are given in milligrams 

 per liter of tyrosine-tryptophan for the 

 first three cruises, and for tyrosine 

 thereafter. The determinations for the 

 first three cruises were according to the 

 method of Erdman and Little (1950) and for 

 the remainder by an adaptation of the 

 method of Sizer and Peacock (1947). There 

 are no data for interconversion of the 

 results. Wangersky developed the latter 

 method and his description follows: 



"The sea water samples were treated 

 with an equal volume of 0.25 normal 

 NciOH, then autoc laved for five hours at 

 a pressure of forty pounds. The seunples 

 were trcuisferred after cooling to cen- 

 trifuge tubes, a small amount of celite 

 was added to each tube, and the samples 

 then spun for ten minutes at 900 - 1000 

 revolutions per minute. The supernatant 

 liquid was then drawn off into a quartz 

 or silica spectrophotometer cell, cind 

 read at 2400 A. on the Beckmsin model 

 D. C. spectrophotometer. 



"Since a few of the sample bottles 

 may lose fluid by expansion during the 

 autoclaving, the Scunples were run in 

 triplicate. The slope of the Beer's 

 law curve for this anailysis varies with 

 the temperature, pressure, and time of 

 heating, maiing it advisjible to run a 

 full set of stcindards with each batch 

 of samples. The celite was added in 

 order to settle the slight haze of col- 

 loidal magnesium hydroxide, which would 

 have otherwise given a false high read- 

 ing. If the celite was added before 

 the autoclaving,' the high temperature 

 caused it to decompose, giving a reading 



even higher than the magnesium 

 hydroxide alone. 



"The standards and blanks were 

 made equivalent to normal sea water 

 in NaCl and Mg ++." 



Carbohydrates . By the method of Erd- 

 man and Little (1950). See also 

 Collier at al. (1953), and Zein-Eldin 

 and May (in press). 



URANIUM AND PHOSPHORUS CONCENTRATIONS 



IN CERTAIN SAMPLES OF WATER AND SEDIMENTS 



FROM THE GULF OF MEXICO 



At the time these cruises were in 

 progress the U. S. Geological Survey was 

 interested in the uranium and phosphorus 

 concentrations in the water and bottom 

 sediments. The samples were collected 

 aboard the ALASKA and forwarded to the 

 Trace Element Section of the Geological 

 Survey for analysis. We are indebted to 

 the Geological Survey through Dr. Frank 

 Grimaldi and his associates for making 

 these data available for inclusion here. 

 The data are presented in the following 

 tables. Phosphorus was determined by a 

 method essentially that of Quinlan and 

 DeSesa (1955). Uranium was determined by 

 fluorometric analysis (Grimaldi, May, and 

 Fletcher, 1952). 



REMARKS ON ANALYSES OF 

 ORGANIC COMPOUNDS 



Since this is the first oceanographic 

 investigation to incorporate a systematic 

 survey of specific classes of organic com- 

 pounds, it is appropriate to give some of 

 the reasons for doing so. 



It is known that biologically active 

 orgjinic compounds exist in solution or 

 suspension in variable concentrations in 

 natural sea waters (Collier, Ray, Mag- 

 nitsky, and Bell, 1953). The possible 

 significance of these compotinds was re- 

 viewed by Collier (1953). The generally 

 low concentrations of carbohydrate-like 

 materials in the Gulf of Mexico was sus- 

 pected and recognized in our easlj work 

 (Collier et al . , 1953). However, when the 

 present series of oceanographic studies 

 was being planned it was considered desir- 

 able to study this matter in more detail. 



