New York Agricultural Experiment Station. 175 



merely traces of putrescine. The fact that the cheese was of 

 good flavor, except for a sHght taste of creosote, indicates that 

 putrescine could not have been present in considerable 

 quantities. 



proteolytic end-products in the cheese containing 



chloroform. 



The cheese containing chloroform was, at the end of 32 weeks, 

 treated, preparatory to extraction, in the manner described 

 above in the case of the normal cheese. It was extracted with 

 several portions of water at 122° F. (50° C.) until about 12 

 liters of extract were obtained, the mass having been completely 

 extracted by this treatment. The water extract was treated with 

 tannin and filtered; the tannin was removed by lead acetate; the 

 precipitate was filtered and well washed. The excess of lead was 

 removed by sulphuric acid and the last traces by hydrogen sul- 

 phide. The filtrate was concentrated at a low temperature, 

 never above 131° F. (55° C), to a small volume. It was then 

 precipitated by phosphotungstic acid, filtered and well washed 

 with dilute sulphuric acid. 



Tyrosine. — After removing the phosphotungstic acid by 

 barium oxide and then the barium hydroxide by careful treat- 

 ment with sulphuric acid, the solution was concentrated to a 

 small volume and set aside for crystallization. After standing 

 several days, there separated from the solution a mixed crys- 

 talline and gummy mass. This precipitate was filtered, dissolved 

 in a small volume of water poured into cold 95 per ct. alcohol 

 and allowed to stand several days. A crystalline precipitate 

 formed at the bottom of the solution. The precipitate was 

 filtered, redissolved in water, decolorized with charcoal and fil- 

 tered. On concentration, this filtrate deposited a copious crys- 

 talline precipitate, greatly resembling tyrosine in appearance. 

 These crystals were washed with ether and dried over sulphuric 

 acid in vacuo. A determination gave 7.70 per ct. of nitrogen, as 

 compared with 7.73 calculated for tyrosine. 



We were unable to find in this cheese any trace of 

 oxyphenylethylamine. 



