November 7, 1913] 



SCIENCE 



677 



C. S. Hudson and T. S. Harding: The Estimation 

 of Baffijiose by a Modified Biological Method. 

 William Salant and J. B. Eieger: The Elimina- 

 tion of Zinc. 



The experiments were made on rabbits. Zine 

 was given intravenously and zinc acetate subcu- 

 taneously. The urine collected for period of 24- 

 48 hours showed the presence of 1-2 milligrams of 

 zinc. Much larger amounts were found in the 

 feces and contents of the gastro-intestinal canal 

 after the subcutaneous injections. The quantities 

 of zinc varied between 8.5 and 17.1 milligrams in 

 24-48 hours, which represented 10-34 per cent, of 

 the amounts introduced. The amounts of zine 

 eliminated by this channel were greater after in- 

 travenous injection, being 17-20 milligrams, or 40 

 per cent, of the quantity administered. 

 William Salant and L. P. Treuthardt: The Ab- 

 sorption and Fate of Tin in the Body. 

 Tin in the form of a double salt was given sub- 

 cutaneously and by mouth to different animals. 

 Analyses of the urine and feces, contents of the 

 stomach and intestines, which were made gravi- 

 metrically and volumetrically, gave the following 

 results : After the subcutaneous administration 

 5-15 per cent, was eliminated in the urine in 24- 

 48 hours. The feces of the corresponding period 

 contained much smaller amounts. The contents of 

 the stomach and intestines and the feces contained 

 as much or more tin than the urine. In some ani- 

 mals the amount of tin eliminated by the kidneys 

 was smaller than that recovered from the gastro- 

 intestinal contents and feces. 



Analysis of the skin indicated the presence of 

 20-25 per cent, of the amount of tin injected. 



When double salts of tin were given by mouth, 

 small quantities of it were found in the tissues and 

 in the urine, indicating that absorption from the 

 gastrointestinal canal takes place to a very small 

 extent only and may be insignificant in some ani- 

 mals. 



The amount of tin found in the liver of rabbits 

 at the end of 48 hours varied between 0.6 per cent. 

 and 10.8 per cent. The kidneys of such animals 

 contained quantities varying between 1.6 and 8.2 

 per cent, of the amount of tin injected. Experi- 

 ments on the absorption of salt from the blood 

 indicate that 85-95 per cent, may disappear in 

 2-3 hours after the intravenous injection of 70- 

 200 milligrams tin. 



Donald D. Van Slyke and Gustave M. Meteb: 

 The Fate of Protein Digestion Products in the 

 Body. 

 Previous work by the authors has shown that 



during digestion amino acids are absorbed into 

 the blood, as the amino acid nitrogen of the latter 

 per 100 CO. rises, in a dog, from 4-5 mg. before 

 feeding to 10-12 mg. after a meal of meat. The 

 low concentration of amino acids in the blood even 

 at its maximum indicates that the digestive prod- 

 ucts must be removed rapidly from the circula- 

 tion. This is found to be the case after the injec- 

 tion of amino acids directly into the circulation. 

 They disappear from the blood almost as fast as 

 they enter it. Analysis of the tissue shows that 

 these have absorbed the amino acids from the 

 blood, vrithout subjecting them to any immediate 

 chemical change. This apparently follows later, 

 but in the muscles is so slow that no decrease in 

 amino acid nitrogen can be determined within the 

 first 3-4 hours after the injection. In the liver, 

 on the other hand, the amino acids absorbed as the 

 result of the injection have entirely disappeared in 

 this time, indicating that the metabolism of these 

 products is particularly rapid in the liver. It is 

 less so in the other organs, but whether as slug- 

 gish as in the muscles is not yet certain. During 

 starvation the amino nitrogen of the tissues, which 

 amounts to 40-80 mg. per 100 gm. of fresh tissue, 

 tends to increase rather than disappear, indi- 

 cating that the amino acids of the tissues can 

 originate from autolysis of the tissues themselves 

 as well as from digestion of food proteins. 



George Peiece: The Configuration of Some Eep- 



toses. 



(Z-u-mannohexahydroxyheptoric acid and d-a- 

 galahexahydroxyheptoric acid yield on oxidation 

 two pentahydroxykinetic acids that are optical 

 antipodes of each other. The configuration of four 

 of the asymmetric carbon atoms in each mono- 

 basic acid is known and the configuration of the 

 fifth is given by the above fact. The correspond- 

 ing heptites are also optical antipodes. 



COH COH CO,H COH 



HCOH HOCH HOCH HCOH 



HOCH HOCH HOCH HOCH 



HOCH HOCH HCOH HCOH 



HCOH HCOH HCOH HCOH 



HCOH HCOH HOCH HOCH 



CHOH CHOH CHOH CHOH 



I. II. III. ' IV. ' 



From d-mannose. From d-galactose. 



Of the following four configurations I. and III. 

 are seen to be the two that give optical antipodes 

 on oxidation or reduction of the end carbon atoms. 

 These two are, therefore, the formulae for the 

 a compounds. The /3 galactose compounds of 



