My family just watched the movie “Windtalkers” and we're wondering whether it's true that the Navajo language code was never broken by the Japanese. What can you tell us about the Navajo Marines who participated in this program? (from E.J., by email)

Dear E.J.: Yes, it's true that the Navajo code was never broken, but neither were most other American cryptosystems. There are other myths in the movie, too, that should be debunked, like the idea that there was a bodyguard for each codetalker who would kill him if he was in danger of being captured.

The real story of American Indian codetalkers is remarkable and goes back to World War I when eight Choctaws communicated via trench telephones for the 36th Division U.S. Army. During the Second World War, many tribes participated in trials, including Comanche, Ojibwa, Muskogee and Oneida, but the available speakers of both English and their native languages were insufficient for the Army's needs; the only tribe with enough bilingual military-age men was the Navajo with 50,000 members. One of the advantages of using Navajo speakers was the intonation of voiced and unvoiced consonants; another was the different grammatical modes; most important, perhaps, was the speed with which messages could be transmitted.

The first class of codetalkers was inducted in May 1942 and sent to Camp Elliott in California where they established a lexicon that ran to eight single-spaced typed pages. They deployed to Guadalcanal in September of that year and served throughout the Pacific theater. By the end of the war, there were over 420 codetalkers operating on at least six Navajo radio networks. During the Iwo Jima landing, more than 800 messages were transmitted in Navajo; not one was decoded by the Japanese.

- - - - - - - -

POISON IVY TREATMENT REDUX: Dan Upton wrote to offer an alternative to calamine lotion. “I read your article about treating poison ivy and poison oak. There is a much better product on the market than calamine lotion. It's called Technu. It's a neutralizing liquid soap that is easily applied and washed off. I am often exposed to poison oak through my work and have found Technu a reliable and effective product for removing the oil from poison oak. The liquid soap is simply applied to any exposed skin surface. Washing and rinsing removes the oil. It's easily applied in the field, too. Hopefully, this is some helpful information you may choose to include in a future article.” Thank you, Dan, for sharing your experience with a safe and easy alternative to calamine lotion. It sounds perfect for hikers, campers, and kids playing in the woods.

- - - - - - - -

I'm concerned that my home-grown tomatoes are cracking. They look pretty ugly. Why does this happen and what can I do to prevent it? (from Callie, by email)

Dear Callie: The main reason tomatoes crack is that their water supply is interrupted or irregular. A heavy rain after a dry spell can cause the inside of the fruit to plump up faster than the skin can expand, leading to splits and cracks. Another reason can be temperature fluctuations when the plants are young.

It's very important to prevent cracking as much as possible because bacteria and fungi can enter the fruit through the crack, as can damaging pests. The best way to do this is to mulch the plants well once you've put them into the soil, then water consistently for the season. Tomatoes need between 1 and 3 inches of water a week. This includes both rainfall and watering. If there's a dry spell, water the plants just enough to keep them alive. Once the dry spell is over, gradually increase the watering schedule. Using a fertilizer designed for tomato plants is also a good idea; look for one with phosphorus and potassium rather than nitrogen.

There are also a wide variety of crack-resistant tomatoes. These include Mountain Pride, Juliet, Heinz 1350, Early Girl and Valley Girl. Keep in mind that beefsteak varieties are more likely to crack. Remember, too, that it's safe to eat cracked tomatoes. Simply cut away the affected areas and enjoy the remainder of the fruit.

- - - - - - - -

MYASTHENIA GRAVIS UPDATE: B. Salvatore has written to share a couple of websites that offer additional nutritional information for people with myasthenia gravis. She recommends the Myasthenia Gravis Foundation of America (www.myasthenia.org) and the New Hampshire - Massachusetts Chapter of MGFA (www.ma-nhmgfa.org), which holds monthly meetings at which patients, family and friends are all welcome.

- - - - - - - -

Send questions of general interest to Ask Us, attention Cat Pragoff, New Hampshire Union Leader, P.O. Box 9555, Manchester 03108-9555, or by email at askuscolumn@gmail.com. Due to the volume of mail received, Ask Us is not able send personal replies.