378 R. W. GLASER AND J. W. CHAPMAN. 



solutions. The material treated with the 10 per cent. Na 2 CO 3 

 solution gave slight coagulation tests with acetic and nitric 

 acids showing that a small amount of protein went into solution. 

 The polyhedra treated with the carbonate were examined micro- 

 scopically and it was found that some fragments had partially 

 dissolved while most of the polyhedra, which had apparently 

 resisted fragmentation in the mortar had swollen to double their 

 normal size. 



Concentrated HC1 (37 per cent.) used both hot and cold seems 

 to dissolve the polyhedra with difficulty. The solubility of the 

 bodies in boiling HNO 3 seems to lie between 15 and 20 per cent. 

 We began with 4 per cent. HNOs in which the polyhedra are 

 not affected and worked up to 31 per cent. HNO 3 in which they 

 dissolve instantaneously on boiling. The fact that the liquid 

 clears when some of the lower percentages of HNOs are used is 

 not sufficient evidence that all of the polyhedra have been 

 dissolved. For this reason the solubility of the bodies towards 

 the acid was checked by microscopical examinations. 



(NH),iOH does not seem to affect the polyhedra, but the other 

 alkalies such as KOH and NaOH dissolve them readily. It was 

 found that as low a percentage as 1/16 per cent. NaOH will 

 dissolve polyhedra if they are boiled in the solution. For con- 

 venience 2 per cent. NaOH was used for the following tests. 

 Two grams of ground bodies were dissolved in the alkali by means 

 of heat. The solution was then dialyzed in order to get rid of 

 the alkali. The dialysis was usually complete after 24 to 48 

 hours. At the end of this procedure the proteins remain in 

 solution (i. e., on dissolving in alkali, after which, although the 

 alkali be removed, the polyhedra proteins remain soluble) and 

 the tests for soluble proteins can be applied. We obtained 

 positive reactions with acetic acid, nitric acid, cupric sulphate, 

 mercuric chloride, acetic acid with potassium ferrocyanide and 

 ammonium sulphate. 



It might be well to mention that the percentages of NaOH used were accurate 

 and the material pure. In making up the solution we did not rely on the so-called 

 purity of the hydroxide sticks, but always eliminated every trace of Na2COs by 

 precipitation with Ba(OHl2. 



After determining that the polyhedra are protein in nature it 



