Men who play guitar are sort of a perfectionist. They are very particular about things in their life in general. The right chord, the right pitch, the right music, the right rhythm etc. They may not know something about everything, but they will definitely know everything about something.
The starch test. Many different food groups contain a carbohydrate known as starch. Using an iodine solution, you can test for the presence of starch. When starch is present, the iodine changes from brown to blue-black or purple. change of color to a blue-black or purple color suggests that starch is present. If there is no change in color, this suggests no starch is detectable. Note the change of the iodine to black on the potato (right) but not the apple (left). (10% Tincture of iodine.) Potato contains starch, but apple does not.
Starch belongs to a group of chemical compounds called carbohydrates. They are called this because they contain only carbon, hydrogen and oxygen. Pure dry starch is a white granular powder.