754 The Outline of Science 



chemist is a transformist. With a wave of his wand he changes 

 soft unsaturated fats, which are apt to become rancid and smelly, 

 into hard saturated fats which last and keep sweet. With an- 

 other wave he transforms rank fish oil so that it can be used for 

 soap or even for food. From beef-fat the chemist originally 

 made margarine, but other sources of fat from coco-nut and 

 cotton-seed, from pea-nut and soya-bean may now be added to 

 this excellent "composite butter." The fact is the animal fats 

 are being more and more displaced by vegetable fats. But our 

 point was simply that with a little coaxing the chemist can change 

 a material so that we do not know it when we see it, and that he 

 can make excellent butter without applying to the cow. 



Transformations of Cellulose 



The cell-walls of plants are made of cellulose, a carbohydrate 

 with the same formula as starch (CcHioOs) , which often hardens 

 into wood. We necessarily eat cellulose when we eat cabbage 

 and the like, but we do not get much good out of it, and it is 

 more important in other connections. It has gone to make coal, 

 it forms wood, and it is the convenient starting-point for many 

 of the chemist's transformations. For although he may go back 

 to the inorganic elements, carbon, hydrogen, oxygen, and nitro- 

 gen, it is much more convenient not to have to begin at the very 

 beginning. 



From wood-pulp most modern paper is made, and the deli- 

 cate fibres seen in paper when examined under a microscope are 

 the remains of the cell-walls of the plants. Cellulose is also used 

 for paper cups and napkins, twine and suit-cases; but it is even 

 more important when used along with other materials as in "mer- 

 cerised" cotton, and the artificial silk this can be made to yield. 



In this connection Dr. Slosson makes good use of the story 

 of Nobel's cut finger. 



Alfred Nobe] was a Swedish chemist and a pacifist. One 

 day while working in the laboratory he cut his finger, as 



