191 1] Ernest D. Clark 197 



grams of this dried specimen in loo c.c. of water reqiiired 1.6 

 c.c. of n/100 sodium hydroxide Solution for neutralization. This 

 preparation was then allowed to stand over night with one hter 

 of water containing i c.c. of ammonium hydroxide Solution of 

 0.96 sp. gr. It was next washed with 25 liters of distilled water 

 on a Büchner funnel. After its desiccation in the usual manner, 

 5 grams of the dry material in 100 c.c. of water required only 0.65 

 c.c. of n/ioo sodium hydroxide Solution for neutralization. The 

 acidity of this product was as low as that of Meyer's best 

 preparations. 



Preparation 3. From cur own starch {A). We washed 

 this specimen ( A) of our own starch with 60 liters of distilled water. 

 Washing with the last 30 liters was by decantation. Five grams 

 of this dry specimen in 100 c.c. of water required 9 c.c. of w/ioo 

 sodium hydroxide Solution for neutralization. The main bulk of 

 the material was then washed by decantation with 30 liters more of 

 distilled water. Five grams of the material in 100 c.c. of water 

 now required 6.6 c.c. of n/ioo sodium hydroxide Solution for 

 neutralization. The product was allowed to stand for four hours 

 in one liter of distilled water treated with i c.c. of ammonium 

 hydroxide Solution of 0.96 sp. gr., and then was washed with 20 

 liters of water on a Büchner funnel. Five grams of the material 

 in 100 c.c. of water required 0.9 c.c. of n/ioo sodium hydroxide 

 Solution for neutralization. 



Preparation 4. From cur own starch (5). This specimen 

 (B) of our own starch was treated exactly like Preparation 3 and 

 bad a final acidity equal to the alkalinity of 0.8 c.c. of n/ioo 

 sodium hydroxide Solution. 



Preparations 2-4, inclusive, after treatment with water at 40°, 

 50° and 70°, gave the colors with iodine that were produced after 

 similar treatment of Preparation i. 



3. Dialysis experiments with soluble starch Solutions. Ex- 

 periments WITH SOLUTIONS IN coLD WATER. All the prcparatious 

 of soluble starch were subjected to dialysis. Two gram portions 

 were suspended in 50 c.c. of cold distilled water, the suspensions 

 were transferred to collodion bags each of which was immersed in 



