216 



SCIENCE 



[N. S. Vol. XLIV. No. 1128 



Water 1,000 gm 



Saccharose 50 



Sodium nitrate 2.0 



Potassium dihydrogen phosphate .... 1.0 



Magnesium sulphate -25 



Potassium chloride -25 



Ferrous sulphate -01 



Calcium carbonate 40 



The form in which nitrogen is supplied and also 

 the amount of nitrogen are the most important fac- 

 tors when growth is conducted in the absence of 

 calcium carbonate. Cultures which produce no 

 citric acid when grown in the above media with 3.0 

 grams of sodium nitrate per liter will produce very 

 considerable amounts of citric acid if the sodium 

 nitrate be reduced to 1.2 grams per liter. 



The most favorable media found for the produc- 

 tion of free citric acid was 



Water 1,000 | 



Saccharose 50 



Ammonium dihydrogen phosphate .... 2.0 



Magnesium sulphate -25 



Potassium chloride .25 



Ferrous sulphate -01 



On this media several strains of A. niger will 

 produce almost pure citric acid with only traces of 

 oxalic. 



Growth was conducted on 50 c.e. of media con- 

 tained in a 200 e.c. Erlenmeyer flask at 30° C. 

 Cultures were examined at 6 to 10 days of age. 

 The cultures employed were obtained from Dr. 

 Charles Thom. 



The influence of hydrogen ion concentration, the 

 substitution of other sugars for saccharose and the 

 influence of numerous inorganic salts on this reac- 

 tion have been studied but can not be reported in 

 detail at this time. 



The Equation of Fermentation of Glucose by Ba- 

 cillus coli communis: Oliver Kamm. 

 The acid, alcohol, gas fermentation of glucose by 

 B. coli, as given by Harden,- was found to be a 

 combination of several fermentations. In particu- 

 lar, the lactic acid fermentation was found to 

 proceed independently. In the absence of most in- 

 organic salts and especially of phosphates, evidence 

 was obtained that the gas formation (carbon di- 

 oxide and hydrogen) is due to the secondary fer- 

 mentations of formic acid. 



The Liberation of Ammonia from Ammonium Salts 



by B. Coli Communis: Eobeet Bengis and A. E. 



Eose. 



A synthetic medium containing ammonia lactate 

 and ammonia phosphate was used in growing B. 

 Coli communis in quantity. The bouillon, when 

 aerated, lost appreciable amounts of NH S and the 



2 J. Chem. Soc, 79 [1], 610-28. 



amount that could be removed in this way was in- 

 creased by inoculation with B. Coli communis. In 

 agar media the amount of ammonia given off under 

 sterile conditions was very minute, but upon inocu- 

 lation with B. Coli more NH 3 was liberated than in 

 the bouillon media. 

 The Change in Urinary Constituents following the 



Feeding of B. Coli Communis : Arthur Knudson 



and A. E. Eose. 



The dogs were kept on a basal ration for long 

 periods. This ration consisted, in part, of a fixed 

 amount of bouillon which was inoculated at stated 

 intervals with B. Coli communis. There was a 

 rapid increase of indican and etherial sulfur elimi- 

 nated in the urine following the inoculation of the 

 bouillon, but these gradually decreased for a 

 period of 2 to 3 weeks to the status of the normal 

 periods, though B. Coli was still introduced. After 

 a period of rest from B. Coli, the inoculation again 

 produced an increase in these two constituents in 

 the urine of the dogs, with the same gradual de- 

 crease. Other changes were noted. 

 The Analysis of the Urine as a Part of the Physical 



Examination of the College Student: G. O. 



Higlet, E. T. Lowrey and C. T. J. Dodge. 



This work was begun in September, 1915. From 

 the urine voided by the student at the close of the 

 physical examination a sample was taken and 

 tested for albumen and dextrose and, in some cases, 

 for other pathological substances. If any such 

 substance was found, the student was advised to 

 consult a physician. Also, the student's urine was 

 reexamined twice, at intervals of a month or so, if 

 found necessary. 



Of 426 students who took the test, the urine of 

 15 showed albumin in two successive tests, and 5 

 showed sugar. A strong test for bile was obtained 

 in one case. This work will be continued next year. 

 Plant Immuno-Chemistry : E. W. Thatcher. 



The question as to whether there is in plants a 

 series of phenomena comparable to those of anti- 

 bodies in animals has not yet been settled, but is 

 now being investigated. Two general methods of 

 investigation are being employed: (a) a compara- 

 tive biochemical study of the composition of 

 healthy and diseased plants, and (6) a biochemical 

 and microehemical study of the reactions pro- 

 duced in the host by the growing parasite. Suffi- 

 cient progress has been made to justify the recog- 

 nition of two types of resistance, or immunity; 

 (a) an antagonism of the tissue substances of the 

 infected plant to the action of the enzymes or other 

 agents excreted by the growing hyphas of the para- 

 site, and (6) a hyper-sensitiveness of the host, 

 whereby its tissues at the point of entrance of the 



