COMPARISON OP RESULTS 



1 I 7 



The apparatus is held in place by angle irons soldered to the 

 bottom of the tank and a brace resting against the upright bar 

 bearing the gear-wheels. 



The water in the tank is heated by injecting steam, or by 

 burners under the tank. As the tank holds about 300 pounds 

 of water it is not subject to sudden changes of temperature, 

 and little trouble has been experienced in raising and lowering 

 the temperature of the water and maintaining it at any desired 

 temperature. 



An electric motor, or a small water-motor with only a very 

 moderate head of water, will furnish ample power. 



105. Comparison of Results. The following data show the re- 

 sults obtained by the digester as compared with those furnished by 

 the official method, temperature and time of digestion being the 

 same in each instance. 



AMMONIUM CITRATE SOLUTION ON PHOSPHATES. 



Total 



Time 



of 

 Substance. treatment. 



{ Yt hour 



1 " 



2 hours 

 Steamed bone, .................. -j 3^ " 



5 

 lYt 



Marl, 



hours 



f Yt hour 

 II " 

 Acidulated bone, .......... ........ { 2 hours 



Bone, ............................ Yi hour 



Ammoniated dissolved bone, ...... Yt 



Cottonseed-meal and castor pomace, ^ 



Phosphobone, ............ . ...... % 



In comparing duplicates, the results from the use of the 

 digester are found to be subject to less variation than those from 

 the usual method. It is seen that in many, in fact, the majority 



