222 



SCIENCE 



[N. S. Vol. XXXIV. No. i 



decomposed thaa those in similar extracts of heart 

 muscle. 



The Effect of Pregnancy on the Lipins of the 

 Ovary and Corpus Luteum of the Cow: Jacob 



EOSENBLOOM. 



(From the Laboratory of Biological Chemistry 

 of Columbia University, at the College of Physi- 

 cians and Surgeons, New York.) 



A comparative study of the amounts of neutral 

 fat, fatty acid, leeithan and cholesterol, in ether 

 and alcohol extracts of the ovary and corpus 

 luteum of the cow, showed that pregnancy had no 

 effect on the respective proportions in which these 

 substances appeared in the extracts. 



Selation of Permeability to the Fertilisation of 

 the Ovum: B. P. Lyon and Shackell. 



Demethylization under Normal and Pathological 

 Conditions: I., Chronic Alcoholism: Wm. Sal- 

 ant and I. K. Phelps. 



Elimination of Caffein in the Urine: Wm. Salant 

 and J. B. Rieger. 



The Effect of Diet on Resistance to Drugs: Wm. 

 Salant. 



The Stability of the Photogenic Material of the 

 LampyridcB and its Probable Chemical Nature: 

 F. Alex McDermott. 



The photogenic compound present in the Lam- 

 pyridse is much more stable towards atmospheric 

 oxygen than has usually been thought, especially 

 when dried out of contact with air; it presents 

 many points of similarity to other known biologic 

 products; from embryologie and chemical consid- 

 erations it appears probable that it is a lipoid or 

 lecithin. 



Gases of Swiss Cheese: William M. Clakk. 

 The Brine Soluble Compound found in Cheese: 



L. L. Van Slyke and Alfred W. Boswobth. 



(Chemical Laboratory, New York Agricultural 

 Experiment Station, Geneva, N. Y.) 



Investigations which have been conducted in this 

 laboratory during the past years have shown that 

 during the ripening of Cheddar cheese a form of 

 protein is always produced which is soluble in a 

 5 per cent, sodium chloride solution. The presence 

 of this brine-soluble compound was shown to be 

 connected in some way with the development of 

 acid in the cheese. The compound was at first 

 erroneously supposed to be paracasein-monolactate 

 and later free paracasein. In recent work it was 

 noticed that calcium was always to be found asso- 

 ciated with this brine-soluble compound when it 

 was separated from the other cheese constituents 



by extraction with solution of e.p. sodium chloride 

 (free from calcium), after first removing the 

 water-soluble constituents. 



This brine-soluble compound is always present 

 in Cheddar cheese. In a cheese two years old 40 

 per cent, of the nitrogen was present in this form. 

 It is also a fact that in cheddar cheese all of the 

 calcium is never extracted with water, part of it 

 always being found in the brine extract. In cam- 

 embert cheese, however, the reverse is found. 

 After the first few hours this cheese contains no 

 brine-soluble compound and all the calcium is 

 found in the water extract. The brine-soluble 

 compound is formed in this cheese, but, owing to 

 the method of making, more acid is allowed to 

 develop than in cheddar cheese and, as a conse- 

 quence, the brine-soluble compound loses its cal- 

 ciiun and thereby becomes free paracasein, which 

 is insoluble in brine solution. 



We believe that, according to the evidence in 

 hand, the following equation represents the reac- 

 tion which takes place where the compound in 

 question is taken into solution by a salt solution : 



Calcium caseinate + 2 NaCl ?=i 



Sodium caseinate -|- CaCL. 



We believe that the mass action, thus repre- 

 sented, is also connected with the precipitation 

 produced upon adding calcium chloride to the 

 brine-soluble compound after its solution has been 

 freed from excess of chlorides by dialysis. 

 The Influence of Sodium Chloride on the Pre- 



oipitability of Casein by Acetic Acid, and its 



bearing on the Partition of Nitrogen in Butter: 



Wm. N. Beeg. 

 The Estimation of Creatin : Stanley E. Benedict. 



Twenty e.c. of urine (or a volume equal to 

 twice the amount which will be required for an 

 accurate creatinine reading) is treated with 20 e.c. 

 of approximately normal hydrochloric acid and 

 the mixture boiled nearly to dryness in a beaker 

 or open flask. After the mixture has almost 

 reached dryness it is placed in a boiling water- 

 bath, and allowed to remain there for about five 

 minutes after the residue is approximately dry. 

 With the aid of warm water the residue is then 

 washed into a fifty e.c. volumetric flask, the mix- 

 ture cooled and five e.c. of 8-10 per cent, basic 

 lead acetate solution added, and the mixture di- 

 luted to exactly fifty e.c, and mixed by shaking. 

 The mixture is filtered through a dry filter into a 

 dry beaker and twenty-five e.c. of the filtrate used 

 for the colorimetric determination as in Folin's 

 process, save that six e.c. 10 per cent, alkali are 



