238 GENERAL SCIENCE 



preserved with such chemicals. Eat food that you know is whole- 

 some. 



Eggs Preserved. A 10 per cent solution of silicate of soda 

 (water glass) is used extensively for preserving eggs. It forms a thin 

 film over the egg, preventing bacteria from entering. 



QUESTIONS 



1. What is the best way to preserve foods? 



2. Why should we avoid all food preserved with alum, boracic 

 acid, benzoic, etc.? 



3. Why does water glass preserve eggs? 



4. Why should paper be wrapped about fruit? 



5. What is the best way of preserving ketchup? 



6. Why should the use of saccharin in food be objectionable? 



7. Why do doctors use it as they do other medicines? 



8. Name some medicines in the same class as saccharin which 

 we would not think of taking unless we were ill. 



9. What is apt to be the condition of soda fountain goods that 

 are preserved with benzoic acid? (TO of 1 per cent.) 



10. Why are bottles containing liquid often deceptive as to the 

 amount of contents? (Refer to Illustration, page 244.) 



11. How can you compare the contents of bottles? 



12. Compare the capacity of extract bottles with some medicine 

 bottles. 



13. Examine the labels on your ketchup bottle, can of peas and 

 other canned foods. 



14. Make an exhibit of all the different containers of foods and 

 labels you are able to obtain. 



SIMPLE PURITY AND ADULTERATION TESTS 



To Decide the Freshness of an Egg. Candling is one of the 

 methods most frequently used. In a darkened room hold an egg 

 between the eye and an artificial light. A fresh egg should appear 

 unclouded and almost translucent. If dark spots are found, it is 

 stale. A rotten egg appears dark colored. 



