cent total amide of <0.1 for each 1% of meta isomer present.Because the absorptivities of the ortho and meta isomers at the designated wave lengths are of similar magnitude, the ortho estimate would provide an indication of the combined ortho and meta contents if the meta isomer were present.The toluenesulfonamides are only very weakly acidic. Strong alkaline solutions must be employed to suppress hydrolysis of the sodium salts and ensure against amide loss during extraction.The high pK" values (about 10) would dictate similarly strong basic conditions to ensure a single moiety if the ultraviolet absorption measurements were made on alkaline solutions. Although successful determinations were performed under these conditions in preliminary work, acidified solutions are prescribed for routine use to reduce risks of background absorption and cell etching.

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Macrornolecrtlar chelating agents possessing high selectivity for rare metal ions have been synthetized. One o j these, with the complexing group of glyoxal bis-2-mercaptoanil, is suitable for selective enrichment of gold from sea-water, while another is suitable for copper and uranium. -The enrichment of metallic ions in nature is discussed, taking hemocyanin as on example. -Both stereochemistry and isomerism, as well as cyclic conjugation during chelate formation, may influence the selectivity of cornplexing agents. The quasi-aromatic properties of clielates are discussed.

it is necessary to have as many relations between the p¡ as their number.The Method of Lagranges Undetermined Multipliers.A powerful tool in the solution to extremum problems is the so-called Undetermined-Multiplier Method due to Lagrange. The problem is typically the following. An alge-

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1. Proteolytic (substrate nitrocasein), tripeptidase (substrate glycylglycylgly-cine) and aminopeptidase (substrate leucyl-beta-naphthylamide) activities were studied in homogenates of jejunal and ileal mucosa of 7-, 10-, 14-, 21-, 35- and 60-day-old rats. 2. Proteolytic activity was practically the same in jejunum of 7-, 10-, 14- and 21-day-old rats, but after day 21 a significant increase was observed. The activity of the ileum changed very little during postnatal development and was always higher than that of the jejunum. 3. Tripeptidase activity was low in the jejunum of 7- and 14-day-old rats, an increase was observed between day 14 and 21, but later no substantial changes were found. There were no changes in the ileum. The activity in the jejunum of 7- and 14-day-old rats was lower than in the ileum, but later the jejunum was more active than the ileum. 4. Aminopeptidase activity had a similar developmental pattern to tripeptidase activity. A low activity was found in the jejunum of 7- and 14-day-old rats, the maximum was in 21-day-old rats and then a decrease was observed, though values for 60-day-old rats were still higher than for 7- and 10-day-old rats. The activity in the ileum was practically the same in all age groups studied except in 14- and 21-day-old rats, where a transient peak was observed.

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In contrast to tetracyanoethylene (TCNE), which is a x complexing agent with some selectivity for methyl substituted benzenes and phenols, 2,4,7trinitro-9-fluorenone (TNF) complexes more strongly with aromatic molecules having at least three fused ringse.g., phenanthrene, pyrene, perylene, etc. TNF and TCNE are compared as to their complexation of various