132 Kansas Academu of Science. 



acid. The jars were inverted and allowed to stand six months. 

 At the end of that period the following things were noted : 

 condition of the cap, loss in volume, condition of solution, 

 whether clear or turbid, and the presence of zinc. The follow- 

 ing results were obtained : 



I. On five out of seven jars the White Crown caps were in 

 perfect condition. The outer rims of two caps were slightly 

 corroded. All of the Mason caps were corroded. 



II. There was no loss in volume in the jars sealed with 

 White Crown caps. In five of the seven jars sealed with Mason 

 caps there was a loss in volume. Two jars had completely 

 evaporated, one had evaporated one-half, another three- 

 fourths, and the fifth had a slight loss. 



III. The solution in each of the jars sealed with White 

 Crown caps was clear, while in two of the jars sealed with 

 Mason caps the solution was decidedly turbid. 



IV. Zinc was absent in each of the solutions in the jars 

 sealed with White Crown caps and present in each of the 

 solutions sealed with Mason caps. 



The general conclusions are that the White CroM^n cap is 

 superior to the Mason cap : 



1. It does not permit the contents to come in contact with 

 any metal. 



2. It is more sanitary in that it is more easily cleaned. The 

 whole surface is smooth. 



3. It permits a tighter seal. 



