100 Proceedings of Indiana Academy of Science 



gases are connected there is a diffusion of the gases into each other 

 which, unless the gases are appreciably polar like HCl+NHs, is of the 

 mixture type of solution. Here the laws of mixtures hold. In the same 

 way, when a gas dissolves in a liquid, if the gas is not appreciably polar, 

 Henry's law is obeyed. Non-polar organic liquids like the paraffins, 

 or benzene and its homologs, have very little tendency toward secondary 

 valence combination. The attraction of the molecules for each other is 

 analogous to gravity and is proportional to their molecular weights. 

 Indeed since the mutual attraction of two bodies is inversely propor- 

 tional to the square of the distance between them gravity alone may 

 well be sufficient, when they are touching, to hold the heavier mole- 

 cules together. If these are the only forces acting, the laws of mixtures 

 should hold. Thus we find that the vapor pressures of solutions of 

 benzene and toluene may be exactly predicted from the concentration. 

 Where there is a polarity effect superimposed, deviations from these 

 simple laws are to be expected. 



In the polar solvent, water, the lower alcohols, the lower organic 

 acids, polyhydric alcohols and the sugars are found to be extremely 

 .soluble. These compounds have sufficient polarity to bring about the 

 secondary valence type of solution. But when we come to the higher 

 alcohols or acids, the ethers and similar compounds which do contain 

 a polar oxygen, but which have so many nonpolar carbons that the 

 polarity of the oxygen is greatly diminished, the solubility varies with 

 the likeness in degree of polarity.' This gives a valuable method for 

 the prediction of .solubilities. 



The properties of many organic sub.stances can be largely predicted 

 from the principles laid down here. In general, nitrogen and oxygen 

 in organic compounds are the seats of most reactions. The reason for 

 this is chiefly because of their polarity, modified by the extent and 

 arrangement of the carbons. The halogens, sulfur, phosphorus, etc., 

 have similar properties to a lesser extent. Some work has been done 

 on explaining oiganic reactions according to the octet theory by Lang- 

 muir, Stieglitz, Huggins and others,'" but only a start has been made. 

 It is hoped to make a study of certain organic reactions along the 

 line of the above reasoning. 



Summary. 



A plausible explanation of the physical and chemical properties 

 of water has been made by an extension of the Lewis-Langmuir theory 

 of atomic structure. 



'•'The more nearly alike two substances arc in their ileKrco of jiolaiity the greater 

 the tendency to form miscible solutions. Substances widely sei)arated in degree of 

 polarity have very slight if any mutual solubility. The lower alcohols and organic 

 acids are completely miscible in water ; ether is somewhat soluble while benzene and 

 the saturated hydrocarbons are so very non-polar that they are practically insoluble in 

 water. 



"Langmuir. J. Am. Chem. Soc, i2, 274 (1920). Stieglitz. ibid., /,.(, 1293 (1922). 

 Huggins. ibid., .',.}. 1B07 (1922). Crocker, ibid., J,.',. 1618 (1922). Conant. ibid., i.l, 

 1705 (1921). 



