6 



SCIENCE. 



[N. S. Vol. XXII. No. 549. 



AVhat we need from the mathematics 

 teacher is, not for them to produce young 

 men who can juggle equations, but to pro- 

 duce young men who can recognize the 

 relations of things. 



My limit of time is presumably ex- 

 hausted, and I will conclude. You prob- 

 ably will not all now agree with my opin- 

 ions,- but fair opinions honestly spoken 

 ought to offend no one ; and I am satisfied 

 that my opinions will be sustained in the 

 minds of the majority of experienced 

 teachers in engineering colleges who have 

 given careful thought to the question be- 

 fore us. When the University of Wis- 

 consin puts into effect a year hence its 

 promulgated additional requirements in 

 algebra preparation for students entering 

 the college of engineering, it' is not so much 

 because we particularly care for more pages 

 of the book to be covered in the high 

 schools, but because we hope that the 

 students (with more time allotted to the 

 subject) may attain more of the true 

 powers of reasoning that come from search- 

 ing for and recognizing the relations of 

 things. 



If a teacher's pupils are capable of trans- 

 forming (juggling) equations correctly ac- 

 cording to rule, without giving a thought 

 to the meaning of the forms produced, or 

 are capable of following through an arith- 

 metical problem by the approved method 

 without considering the reasonable accu- 

 racy of the numerical results, then that 

 teacher's sowing has been choked with 

 tares. But a teacher of mathematics who 

 leads his pupils to give due thought in the 

 course of their work to interpreting equa- 

 tions, to noticing the relations of things, 

 and to scrutinizing and checking the accu- 

 racy of every numerical result (even 

 though the pupils may evolve, for their 

 own use, awkward and unapproved an- 



alytical methods)— that teacher's sowing 

 is of golden wheat. 



DuGALD C. Jackson. 

 Univeksity of Wisconsin. 



THEORIES OF METABOLISM} 

 The sum of the chemical changes Avhich 

 take place within the organism under the 

 influence of living cells is called metab- 

 olism. This paper is to discuss the char- 

 acter of these changes and to consider, as 

 far as we may, their cause. 



It was Lavoisier who first understood 

 that oxygen supported combustion and he 

 compared life with the flame of a candle. 

 He conceived the idea that hydrogen and 

 carbon were brought to the lungs by the 

 blood and there united with oxygen. It 

 was, however, observed that the heat pro- 

 duction was not confined to the lungs, and 

 when Magnus found that venous blood was 

 richer in carbon dioxide and poorer in 

 oxygen than was arterial blood, the process 

 of oxidation was placed in the blood. Lud- 

 wig in his later years believed this. The 

 prevailing view, however, is that the proc- 

 esses of metabolism take place within the 

 cells of the body. 



Lavoisier believed that oxygen was the 

 cause of the metabolism. Liebig thought 

 that fat and carbohydrates were destroyed 

 by oxygen, while proteid metabolism took 

 place on account of muscle work. Voit 

 showed that muscle work did not increase 

 proteid metabolism and that the metab- 

 olism was not proportional to the oxygen 

 supply. The amount of oxygen absorbed 

 apparently depended upon what metabo- 

 lized in the cells. He showed that although 

 fat burned readily in the air, it burned only 

 with great difficulty in the body; and that 

 proteid burned with comparative difficulty 

 in the air, but went to pieces very readily 

 in the body. Voit believed that the cause 



^ A paper read before the New York Section of 

 the American Chemical Society. 



