Where is the Bee—
Where is the Blush—
Where is the Hay?
Ah, said July—
Where is the Seed—
Where is the Bud—
Where is the May—
~ Emily Dickinson, " Answer July"
The earliest glass jars were called wax sealers since wax was poured into a channel around the lip that held on a tin lid. This process was complicated and error-prone, but was largely the only one available for a long time and widely used even into the early 1900s.
From1860 to1900 a great many patents were issued for various jar closures. The more esoteric closures were quickly abandoned and can fetch high prices in today's antique market. Antique mason jars' values depend on the age, rarity, and condition.
The age and rarity of a jar can be determined by its color, shape, mold and production marks, and closure. Most antique jars that are not colorless are a shade of aqua known as "Ball blue," named for the prevalent jar maker. Colored jars were considered better for canning use as they block some light from reaching the food which helps to retain flavor and nutritional value longer. More rarely, jars will turn up in amber and occasionally in darker shades of green. Rarer still are cobalt blues, blacks, and milk glass jars. Some unscrupulous dealers will irradiate jars to bring out colors not original to the jar.
Even so, simple jars have gone up in price since they are gaining the attention of the younger buyers, but the clear jars are still in production, and Ball reproduced the blue jars.
http://www.huffingtonpost.com/2014/06/06/mason-jar-salads_n_5452313.html . There are recipes listed, but here is an example...
Caprese Pasta Salad
2 tbsp basil pesto (homemade or store-bought)
1 cup cherry tomatoes
1 ½ oz fresh mozzarella, chopped into bite sized pieces
2 oz cooked penne pasta
½ cup fresh spinach leaves
½ cup fresh basil, chopped
From another article, "Despite the obvious cuteness factor, these jars will keep your greens fresher than fresh, they won’t stain, they’re BPA free, microwave and dishwasher safe, perfectly sized for salads for one, won’t leak, travel well, and are reusable...There really are only two rules to the mason jar salad: Start with the dressing or sauce, and end with the lettuce and herbs. However you want to layer the rest of the ingredients—try different meats, beans, lettuces, cheeses, vinaigrettes, or sauces—is up to you (though I usually layer by weight so heavier items, like tomatoes, are on the bottom)."
"Let my words, like vegetables, be tender and sweet, for tomorrow I may have to eat them."