146 BENEDICT— THE INFLUENCE OF [February 4, 



It is my privilege to explain to you how it is hoped to develop 

 another line which, while it has by no means the attractive outlook 

 presented by bacteriology and preventive medicine in general, may 

 yet prove to be of the greatest value to mankind. I refer to inves- 

 tigations in the nutrition of man. If by proper study we can find 

 what foods are best adapted to different purposes, if in what quan- 

 tities they should best be ingested, what preliminary treatment is 

 most desirable, we will have solved a great many problems regard- 

 ing the diseases of digestion and will have made a large contribu- 

 tion to a wider branch of preventive medicine. 



While the compound microscope can be used for studying the 

 tissues, it requires a very different type of apparatus for studying 

 the changes that take place in the whole body and the apparatus 

 which, in our investigations, compares in a way to the compound 

 microscope of the bacteriologist has the formidable name of respira- 

 tion calorimeter. The microscope can reveal to us clearly what 

 happens after the tissue is dead; it cannot, except in a few instances, 

 give us a true picture of the processes which take place in the living 

 body. These processes are extremely complex but we do know 

 that as a result of food ingested, we obtain from the body heat, 

 muscular work and mental work, and that there are certain excre- 

 tions. During youth there is also a noticeable growth, while after 

 the growth has been established, there is also repair of waste tissue. 

 It is in studying these particular functions that we find it necessary 

 to resort to a special apparatus — the respiration calorimeter. 



We eat a great variety of foodstuffs and it is necessary for the 

 body to so break down and rearrange the materials in these foods 

 that the body can make the best use of them. For example, ordi- 

 nary sugar cannot be used directly by the body but must first be 

 broken down into dextrose and this dextrose is probably in part 

 converted into another compound which is distributed through the 

 muscles and particularly in the liver — a substance very closely allied 

 chemically to sugar and called glycogen. 



Like the frontiersman building his log house, the standing tree 

 is of no use to him, but after the tree has been felled and the log 

 hewn into the proper shape, then and then only can he begin to con- 

 struct his house. But it is only during youth that the body is par- 



