41 6 The Biochemical Society^ England [June-September 



extract otherwise converted, cooled to 20° C, 30 c.c. of a saturated 

 picric acid Solution and 15 c.c. of a 10 percent sodium hydroxid Solu- 

 tion are added. After standing for 5 minutes the coloured liquid is 

 made up to 500 c.c. The colour is matched in any suitable colourim- 

 eter against that given by the Standard Creatinine Solution. It can 

 also be matched against 8 millimetres of a Solution of potassium 

 bichromate containing 24.54 grammes of bichromate per litre. the 

 colour of which corresponds with 10 milligrammes of creatine in 

 500 c.c. of liquid. 



Residual Nitrogen usually returned as " Meat Bases." The 

 sum of the percentages of nitrogen existing in the form of coagulable 

 proteins, and albumoses and peptones (and of course gelatine, when 

 present) is subtracted from the total nitrogen: the residual nitrogen 

 multiplied by 6.25 is usually returned as " meat bases." It is clear 

 that when creatine and Creatinine are estimated, the nitrogen present 

 in these substances may be deducted from the total nitrogen, in which 

 case the expression " meat bases " must be qualified by the additional 

 words " other than creatine and Creatinine." Perhaps, however, the 

 best mode of expression is to State the percentage of "meat bases" 

 as above, and to point out in an independent Statement that this con- 

 tains such and such a percentage of combined creatine and Creatinine 

 expressed as Creatinine. It is suggested that no useful purpose is to 

 be served by making separate estimations of these two bases, 



It will be interesting to have the views of the Members on the 

 employment of the arbitrary factor 6.25 for the conversion of re- 

 sidual nitrogen into the equivalent of so-called "meat bases" and 

 also on the question of the food value of the various groups of con- 

 stituents mentioned in the above Classification. 



In Order to make the discussion as practical as possible, it is par- 

 ticularly requested that proposals in reference to new or alternative 

 processes of analysis should not be introduced except on the basis 

 of experimental data. 



IL PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS AND 



OTHER ANALYTICAL CHEMISTS, AND THE BIOCHEMICAL 



SOCIETY, IN JOINT SESSION 



Reported by E. Richards Bolton, Joint Hon. Secretary 



May 5. Society of Public Analysts and Other Analyti- 



