THE HYGIENE OF NUTRITION 223 



as to raise the concentration of the intestinal contents 

 appreciably, nor delivered to the blood so abruptly as to 

 increase markedly the percentage of sugar in circulation. 

 It seems safe to assume that the storage of glycogen is 

 effected more smoothly and easily after the ingestion of 

 starch than after the taking at one time of a large quantity 

 of sugar. 



Highly soluble bodies of low or moderate molecular weight 

 are said to confer on their concentrated solutions the prop- 

 erty of high osmotic pressure. This is not the place to 

 discuss what is meant by the expression. For practical 

 purposes it can be said that concentrated solutions take 

 water from tissues with which they may be brought in 

 contact. Hence an irritant effect is to be expected. This 

 is exemplified by the action of strong salt solutions in 

 producing vomiting. Everyone who is fond of candy 

 knows that it can be eaten until a point is reached at 

 which an uneasy sensation of satiety verging on nausea 

 is developed. This is relieved by drinking water, which, of 

 course, lowers the concentration of the syrupy gastric 

 contents and so lessens the irritation. 



Cane-sugar is much sweeter than sugar of milk or the 

 other sugars which arise in the course of digestion. It is, 

 therefore, cloying and its free use may blunt the appetite 

 for other foods. It is said also to be more disturbing to the 

 stomach than the others. These two properties perhaps 

 account sufficiently for the ill effects which are attributed 

 to the increasing consumption of candy in this country. 

 Still it is probable that the evils resulting have been much 

 exaggerated. There is, however, no question that the 

 constant eating of candy threatens to damage the teeth, 

 and the indirect impairment of the digestive powers may be 

 serious. 



The relation between sugar and the decay of the teeth 

 is apparently quite simple. Sugar is prone to ferment, 

 a change brought about by bacteria which are inevitably 

 present in the mouth. The chief product of such bacterial 

 decomposition is lactic acid. This acid attacks the lime- 



