30 BULLETIN OF THE UNIVERSITY OP WISCONSIN. 



taste; which, however, is not sharp and salty like that of chlor- 

 ine and bromine ions. Iodine ions have a salty taste but it is 

 different in quality and less intense than that of either chlorine 

 or bromine ions. It takes about a ■■• solution of iodine ions to 

 produce a distinctly salty taste. 



6. The taste of K0 3 ions is slight, probably a trifle salty; 

 only in strong solutions do they produce a sharp burning sensa- 

 tion on the tip and edges of the tongue. The ions S0 4 and 

 CH3 COO have but very little taste; the effect of the latter 

 seems to be a trifle sweet. 



7. The taste of sodium ions is slight. It is difficult to de- 

 scribe, being a smooth effect on the tongue somewhat similar 

 perhaps to that produced by a very dilute solution of hydroxyl 

 ions. Potassium ions have a more pronounced taste than sodium 

 ions. It is a peculiar, bitter, rather disagreeable taste that can 

 be much more readily detected than can that of sodium ions. 

 Lithium ions have no pronounced taste, their effect is some- 

 what like that of sodium ions, though less in degree. Magne- 

 sium ions are bitter. It takes about a £ solution to cause a dis- 

 tinctly bitter taste. Calcium ions are bitter, but the taste is 

 different in quality from that of magnesium ions. Ammonium 

 ions also have a bitter taste. The taste of silver ions is "me- 

 tallic"; they cause a peculiar puckering sensation on the mem- 

 branes of the mouth cavity. Even a ^ solution of silver 

 ions can still be tasted. Mercury ions can be faintly detected 

 by the sense of taste in ^ solution. Their taste is "metallic" 

 and their effect on the membranes of the mouth cavity reminds 

 one of that of silver ions. 



8. The intensity of the salty taste of the halogen ions de- 

 creases as the atomic weight increases. The investigation of 

 the cathions also indicates that a relation exists between their 

 taste and their atomic weights in the sense of the periodic law. 

 When the taste of the ions is compared with their mobility as 

 expressed by their speed of migration under the influence of 

 the electric current, a number of instances are found that would 

 point to the conclusion that the greater the mobility the more 



