336 Repokt of the Depaetment of Chemistry of the 



Table XV. — Comparison of Changes in Cheddar and Camembert Cheese. 



Age of cheese. 



Kind of cheese. 



When curd was cut 



10 hours 



2 days 



4 months 



Cheddar. . . 

 Camembert 

 Cheddar. . . 

 Camembert 

 Cheddar. . . 

 Camembert 

 Cheddar. . . 



was done: Twenty-five grams of cheese were ground with sand and 

 extracted with water at about 55° C, using 150 cc. portions, until 

 the extract amounted to 1,000 cc. The residue, containing the 

 brine-soluble substance, was placed in a dialyzing apparatus and 

 allowed to dialyze to insure the removal of all soluble calcium. 

 Sodium chloride was then added to the contents of the dialyzing 

 tube, which was then placed in a beaker of water and allowed to 

 remain 4 hours. Upon adding ammonium oxalate to some of the 

 water in the beaker, a precipitate of calcium oxalate appeared. 

 This result leads to the belief that the calcium is present in com- 

 bination in an insoluble form and that an interchange takes place 

 between it and sodium, when the insoluble compound is treated 

 with sodium chloride solution. 



In order to throw further light on the character of the brine- 

 soluble compound, a study was made of the solvent effect of several 

 different chlorides. One kilogram of cheddar cheese was ground 

 fine, thoroughly mixed, and then 25-gram portions were ground 

 with sand, placed in bottles and extracted with water in the manner 

 described in the preceding paragraph. The residues were then 

 extracted with solutions of chlorides and the results given in the 

 following table were obtained. The solutions of the salts were used 

 in such strength that 1,000 cc. contained equivalent gram molecules. 

 In the case of the weakest solution, extraction was continued as long 

 as appreciable amounts of protein were obtained in the extract, 

 4,000 cc. being used; the results in these cases are given for each 

 1,000 cc. of extract, as well as for the total. 



In connection with the data in Table XVI, attention is called to 

 certain phases of the results. 



(1) The chlorides of barium and calcium have no solvent effect. 

 The chloride of magnesium in strong molecular concentrations acts 

 much like the chlorides of sodium, ammonimn and potassium, 

 while in lower molecular concentrations its solvent power is 

 greatly reduced. 



