Sensitivity to caffeine, as with other drugs, varies. Some people drink 5 to 10 cups a day and swear it never bothers them, while some claim one cup makes them nervous. If you like coffee and it doesn't affect you adversely, don't worry so much about having that second cup.
Some drugs accumulate in the system; caffeine does not. It's metabolized at the rate of 15 percent an hour and rapidly excreted from the body.
Q. I have a number of ballpoint pens that have visible ink inside but do not write. Can they be reactivated in any way?
Green Bay, Wis.
A. How devilishly clever the manufacturers of ballpoint pens are, to design a pen that still has ink in it but will not write. Leah Colihan, public relations manager with the Bic Corporation, advises us that the ink has a shelf life. "Like a battery," explains Colihan, "once the ink's shelf life has expired, there is virtually nothing that can be done to restore it."
Notice that the Bic people say that "virtually" nothing can be done to restore the pen. Since virtually means almost entirely, perhaps there is a way to restore the pen after all. Although I've never been able to do it, there must be a reader who knows how to bring a seemingly dead pen back to life. Please let us know.
In the meantime, don't buy 10 pens to a pack, thinking you'll have enough to last you for five years, because they're supposed to self-destruct simultaneously.
Q. I have an 8-year-old Salton espresso machine that was given to me as a gift. I wrote to Salton at a Bronx, N.Y., address for spare parts but the letter was returned with a post office notation that the company had moved, and the forwarding order had expired. Can you provide an address?
Q. I need parts for a Salton yogurt maker but their letters are returned. There's no listing for them in the New York phone book. Can you provide any information?
Cape May, N.J.
A. Consumers who need spare parts for Salton products are presently out of luck. The company was bought by Sevko, which is situated in Illinois. When I called the company to ask for an address where consumers could get spare parts, the person who answered the phone refused to give me authorization to publish their address. She said they didn't want to be deluged with requests for parts at this time. When I asked to speak to one of the executives, she replied that they were all at a board meeting. I left my number but nobody called back. Perhaps eventually they'll get their act together.
Q. In a store I saw bags of sugar for sale and the label said that the sugar was refined from sugar beets. Is this sugar any different from sugar refined from sugar cane? Also, what is the difference between confectioners' sugar and powdered sugar, and can I substitute either one for regular sugar?
Mountain View, Calif.
A. "There is no difference in the sugar refined from either cane or beet," says the Sugar Association. "Sugar cane, a giant grass, thrives in a warm, moist climate, storing sugar in its stalk. The sugar beet grows best in a temperate climate and stores its sugar in its white root. Chemically, sugar
from both sources is the same."