164 EXPERlMENl' S'TATION EECOKD. [Vol.36 



A fraction of the urea which was administered remained in the body after 24 

 hours. This urea was not retained because of any failure on the part of the 

 Icidneys to eliminate it, for the amount retained was no larger when 40 than 

 when 20 gm. of urea were taken." 



Tlie interrelations of blood fat and blood sugar content of dogs under 

 the influence of hydrazin, F. P. Underhill and E. J. Baumann {Jour. Biol. 

 Cheni., 27 (1916), No. 1, pp. 169-172) .—The object of this investigation was to 

 determine the relation of the fat content to the sugar content of the blood in 

 the case of laboratory animals (dogs) under the influence of hydrazin, which 

 results in a low blood sugar content and the loss of glycogen from both the 

 liver and muscles, and induces a so-called " fatty " liver. 



The experiments showed that during the first days of fasting there was a 

 tendency for the blood fat to decrease. This period was followed by one in 

 which there was an increase of fat content up to approximately the initial 

 value. During the interval of inanition studied there appeared to be little or 

 no relation between the blood fat and blood sugar content. 



" In hydrazin poisoning blood fat is markedly increased, the maximum being 

 coincident with the condition of hypoglycemia characteristic of hydrazin. 

 Blood fat returns to the fasting value as the sugar of the blood regains the 

 normal." 



The toxicity of carotin, H. G. Wells and O. P. Hedenburg {Jour. Biol, 

 Chem., 27 {1916), No. 1, pp. 213-216).— The authors describe the method of 

 preparation from fresh carrots of the pigment carotin used in the experiments 

 reported, in which the toxicity of carotin was determined in the case of labora- 

 tory animals (guinea pigs) given intraperitoneal and intradermic injections of 

 the substance dissolved in olive oil. The doses of carotin injected were much 

 larger than the amounts which can be obtained from any food, the larger doses 

 being as much as that contained in 200 kg. of flour. 



" These experiments indicate that even in relatively very large doses carotin, 

 whether in its natural state or saturated with chlorin, is almost entirely devoid 

 of toxicity. Such large amounts as 20 mg. injected intradermically cause only 

 a local edema and inflammation, but no necrosis." 



Clinical calorimetry. — XVIII, The number of places of significant figures 

 in the data of metabolism, experiments, F. C. Gephart, E. F. DuBois, and 

 G. LusK {Joiir. Biol. Chem., 27 {1916), No. 1, pp. 2 17-223) .—Three factors are 

 discussed as influencing the number of places of significant figures in the data. 

 These are the accuracy of the analytical results, the possible errors in the 

 methods of calculation, and the significance of the findings. It is concluded that 

 the analytical error in metabolism work is seldom much less than 1 per cent 

 and that a variation of 1 per cent in the results of an experiment would not 

 change its significance or affect its interpretation. 



" For these reasons, it seems unnecessary to publish more than three signifi- 

 cant figures in tlie tables of data and in some cases it is not worth while to 

 publish more than two. In order to avoid the accumulated rejection error it is 

 advisable to retain four figures wherever possible in the calculations and reject 

 the fourth digit only in the final result." 



A table is given showing the number of places of significant figures adopted 

 as standards in the publication of metabolism data. 



For earlier work in this series see E. S. R., 35, p. 369. 



ANIMAL PRODUCTION. 



Meat situation in the United States.— V, Methods and cost of marketing 

 live stock and meats, L. D. Hall, F. M. Simpson, and S. W. Doty (f^ 8. Dept. 

 Agr. Rpt. 113 {1916), pp. 98, pis. 20).— lu this fifth report of this series (E. S. 



