30 JOURNAL OF THE 



2. The loss of moisture, due partly to thfe vaporizing of water by 

 heat generated by grinding, and partly to the action of the air on 

 the finer particles necessarily exposed during the pulverization. 



3. The decrease in content of Insoluble Phosphoric Acid caused 

 by the more complete action of the solvent on the finer particles. 



4. The increase of the Total Phosphoric Acid caused by the loss 

 of moisture. 



5. The increase of the Reverted and Available Phosphoric Acid 

 due first to the increase of the Total, and second to the decrease of 

 the Insoluble. 



The last four results are shown to be directly proportional to the 

 fineness of the grinding. 



In conclusion, I would suggest the advisability of passing the fer- 

 tilizer sample through a 40 mesh sieve, instead of 20 as is the custom 

 now. This would give better mixing and consequently a more reli- 

 able sample could be taken, and again the fineness obtained would 

 more nearly approach what is required by the plant in the process 

 of its growth. It would not have the disadvantage of the 20 mesh, 

 nor the objection met with in the 100 mesh grinding; neither the 

 coarse mass sampled with difficulty in the former, nor the too great 

 loss of water in the finer particles and the greater solvent action on 

 them in the latter. H. B. BATTLE. 



Laboratory N. C. Exp. Station, 



Raleigh, May 19th, 1886. 



ON THE LOSS OF MOISTURE IN BOTTLED 



SAMPLES. 



H. B. BATTTE. 



Frequently having had occasion to repeat a determination of total 

 phosphoric acid in a commercial fertilizer, I almost invariable found 

 the second determination made two or three weeks subsequent to 

 the first to give a higher result. This variation being so constant I 

 was forced to think that it was not the result of error of analysis, 

 but owing to loss of moisture in the samples. 



The samples of fertilizers used were placed in a wide mouth bottle 

 about 2 oz. capacity and closed with ordinary cork. Five distinct 



