230 REPORT OF THE CHEMIST OF THE 
acid upon the rate at which acids convert casein into solution. The 
acids used in our study are hydrochloric, lactic, sulphuric and 
acetic; the temperatures, 0°, 25° and 45° C.; and the concentra- 
tions, N-125, N-500, N-1000 and N-2000. The numbers in the 
tables indicate degrees of solution, as explained on p. 228 in con- 
nection with Fig. 6. The figures on the left in each column ex- 
press degrees of solution, as shown by the appearance of the filtrate 
when treated with sodium hydroxide; those at the right indicate the 
results of tne xanthoproteic test. 
