In medieval era, the way bodies were prepared for embalming included several steps[1]:

1) spurging (washing)
2) cleansing (emptying of the bowels and plugging the rectum)
3) bowelling (removal of the intestines)
4) searing (cauterising of the tom cavity blood vessels),
5) dressing (the application of a resin mixture in volatile oils),
6) furnishing (wrapping the corpse in cerecloth).

It is the final step that is the most interesting. Cerecloth was supplied by the Grocers and used by the Apothecary as they prepared dead bodies. Cerecloth is cloth that has been soaked in wax with resins that created a moisture barrier around the body and kept out the elements.

The remains of that warlike Prince, Edward the First, repose in a plain tomb of grey marble, which has sustained but little injury. At the request of the Society of Antiquaries, this tomb was opened in the year 1770, and the royal body was found wrapped in a strong linen cloth waxed on the inside. The head and face were covered with a facecloth of crimson sarcenet, wrapped into three folds ; and on throwing open the external mantle, the corpse was discovered richly habited in all the ensigns of majesty. The body was wrapped in a fine cerecloth, closely fitted to every part, even to the face and fingers.[2]

So how does this all tie to sugar work? I went searching for a material that I could use while working sugar, that wasnt plastic wrap. They had to have something for larger sculptures. Sugar paste will harden and crack when it is exposed to air. And it is probable they were not making a lot of small paste batches while working on a large project. It is more prudent to make a larger batch and not have to stop every 2 minutes to make more paste. Cerecloth is a product of the Grocers, used by the apothecaries. It creates an airtight, waterproof seal around things. This means it can be used to keep sugar paste fresh, in a medieval fashion, without using plastic.

For my first experiment, I made a 1/2 lb of sugar paste and kept it wrapped up in cerecloth for over a month. When I cracked open the waxed linen, my sugar paste was still fresh and pliable. It has proven effective as a tool, even in the humid NE summers.

Cerecloth recipe:
I use a high quality mid weight linen that has been washed and ironed. Soak it in melted beeswax, until fully saturated. Hang to dry, Lay flat to store. If you need to clean it, use mild soapy water. You can rewax as needed.

A thesis submitted for the degree of Doctor of Philosophy by Philip Stephen Gore
Department of Sociology, Brunei University December 2005

[2]London scenes, or, A visit to Uncle William in town : containing a description of the most remarkable buildings and curiosities in the British metropolis ; illustrated by 78 copperplate engravings ([1824?])

To purifie and refine Sugar

Refining sugar from cane into a usable product was not an easy task.

To purifie and refine Sugar
Make a strong Lixiuium of Calx vive, whereing dissolve as much course Sugar as the Livivium will beare, then put in the white of Egges (of 2 to every part of the Liquor) being beaten into an oil, stir them well together, and let them boyl a little, and there will arise a scum which must be taken off as long as any will arise, then poure all the Liquor through a great Wollen cloth bag, and so the feces will remain behinde in the bag, then boyl the Liquor again so long till some drops of it being put upon a cold plate will, when they be cold, be congealed as hard as salt. Then pour out the Liquor into pots, or moulds made for that purpose, having a hole in the narrower end thereof, which must be stopped for one night after, and after that night be opened, and there will a moist substance drop forth which is called Molosses, or Treakle, then with potters clay cover the ends of the pot, & as that clay sinketh down by reason of the sinking of the Sugar, fill them up with more clay, repeating the doing thereof till the Sugar shrink no more. Then take it out till it be hard, and dryed, then bind it up in papers.

The basic process contained three steps:

  1. Boil shredded sugar cane to remove the sugar from the plant.
  2. Clarify the sugar syrup by straining through lime water and egg whites or ox blood.
  3. Mold the clarified and strained sugar concentrate into conical molds to cure and dry.

This process resulted in a single refined sugar. This sugar was not often white, but a red or brownish color and it often contained a number of impurities including bits of cane particles and other debris. Each time the sugar was refined, the quality went up.

Most sugar purchased from Grocers was 2x refined.  The sugar was good quality, but not the best. It still retains a yellowish tinge. For this reason, sugar was often wrapped in cobalt blue paper.  Blue caused an optical illusion of making the sugar appear whiter than it actually was.  Unscrupulous grocers could often sell a lesser grade sugar as higher grade, because there was an illusion of “whiteness.”

When I use loaf sugar that is refined in a 18th century fashion, it comes wrapped in blue paper. It appears very white.  As it exposes to air, you can see the yellowing of the impurities. Once it’s been scrapped, you get the perception that the sugar is white again, having “scrapped away the impurities.” However over time and air exposure, it starts to yellow again. This is why you need to refine the sugar further before use in a finished confection. In the Manus Christi, I called this step, skimming the scum.

When I create confections with “period” sugar and modern sugar, I will put them on a cobalt blue background.  The modern sugar is a brighter white due to commercial processing. And in a side by side display (period vs modern), I want you to believe that my confections are of the highest quality. I use the same techniques an apprentice of the time would use, the optical illusion of a bit of cobalt blue. I use wool felt, because the period sugar will grip it and not roll all over the table.

French, John. The Art of Distillation, Or, a Treatise of the Choicest Spagiricall Preparations Performed by Way of Distillation. Lond., 1653. Print p126

Resistaunce of malitious attempts by anny foraigne enemie

The Company was at times called upon to furnish ammunition and even men, both for military and naval service:
In July 1557, the Wardens were to provide 60 good, sadd and hable men to be souldgears, whereof 2 to be horsemen well horsed and armyd, 20 of them to be harquebusiers or archers, 20 to bear pikes and 1 8 to be billmen, all well harnyfhed and weponed, mete and convenient, accordynge to the appoyntment of our Soveraine Lorde and Ladye the King’s and Queene’s Majestie ; as well for the securitie of the Queene’s highness’ most royal person, as for the suretie and safe- guarde of their highnefle’s chambre and citie of London and the resistaunce of such malitious attempts as may happen to be made against the fame by anny foraigne enemie.
Some account of the Worshipful company of grocers of the city of London- BY BARON HEATH  (John Benjamin Heath)

How does this tie into Alesone? She is trained to use black powder, swords, pikes and other fighting/martial activities.  And while I believe they are talking specifically about the funding of the the men for military service, no one ever suspects the confectioner.

Appodiment Experimente- failen

Stale bread does not work as an armature. It failed at a chemical level.

I used stale manchet bread, as this is the type of bread that would be available to a wealthy household in 16th century England. Sugar was rolled to 1/16″ of an inch and sealed around a shield shape of stale bread 1/2″ thick. It was allowed to dry with the other samples created for the A&S event. By the second day, the sugar had cracked and started to ooze some sort of substance.

Cracked sugar

This had the appearance of a modern royal icing. By the time of the event 5 days later, the ooze dried to a hard crust. But flakes of paste started to flake off. The flakes were paper thin and sticky. The bread underneath had a glazed appearance and was also sticky. The consensus of the folks who say the end state was that the carbohydrates in the sugar and bread, were competing for “resources.”

This was a neat failure at the chemical level. However, it makes for a very poor substance to use as an armature. This will be the last time I use this medium as an armature for sugar paste.

Appodiment Experimente

Recreating 16th century appodiments
When building a structure it is important to know the limitations of various materials, and work to compensate for them. Sugar is a temperamental material, prone to many problems. When added to an armature structure, these problems can be compounded.

  • Sugar is heavy. The larger the piece, the more it needs an internal structure for support.
  • Sugar is very porous and extremely hygroscopic. In certain areas of the world, it should be sealed against humidity in order to prevent cracking and rehydration.
  • Metal can add significant weight to the overall piece. Depending on the material used, it can rust and is difficult to seal.
  • Paper, wood, and other plant-based materials (pasteboard) are hygroscopic. This can cause an armature to warp and rot if kept in moist conditions for too long. It is also highly flammable if working with a subtlety, which will be employing fire.

When selecting a material for armature, finding a lightweight, transportable and still structurally sound was critical.

Craft grade aluminum mesh is a good modern armature material. It is rust resistant, very pliable and can be formed easily without the need for specialized tools. Most grades of mesh is “porous” and sugar does not adhere well. Sugar has to be pushed deeper into the structure and this adds significant weight to armature. To prevent this, a secondary layer is applied to the general shape. A shape can be formed and bound with wire, however, once the secondary layer is applied, the wire has a tendency to rust. Silk beading floss is a better option for binding shapes. It can be noted, that plaster mesh can also be used to create a base armature. Though it takes a significant amount of the base material to get a shape formed. This adds to drying time and over all weight to the final piece.

There are several materials that work well over metal armatures. When paper maché/pasteboard is used asthe second layer, it creates a good barrier between metal and sugar. The paper mache’s rough texture is ideal for grabbing sugar paste. The clean white paper pulp does not have a binder and is “activated” with water. It is starch free, which means that it is safe for people with starch/gluten allergies. It is white, which reduces potential ink bleed through to the sugar. The down side to this secondary layer is time. It takes a very long time for the paper to dry completely.

A better material is plaster mesh. The plaster mesh also has a rough texture and is white. It has several advantages over paper. It can be used to create small stand a lone structures hat do not need a metal foundation. It is closer to plaster of paris in behavior than the paper. It has a better bond when securing irregularly shaped pieces of armature together. The fabric nature of the mesh allows it to be freely applied around corners and rounded edges. The dry time for the plaster mesh is roughly 10 hours. The dry time for paper mache is roughly 28 hours. This time difference allows for faster creation of a structurally sound armature.

Plaster of Paris would be the best choice for a more medieval armature. However, the combination of metal mesh and paper maché/plaster mesh does not have the heat or toxicity of plaster of Paris. Plaster of Paris when mixed with water causes an exothermic reaction and can cause severe burns. Chemicals in plaster are considered to be irritants to the skin, lungs, eyes and stomach (if ingested).[1] These hazards make Plaster of Paris dangerous for a re-creationist to use safely.

Paper and pasteboard
Paste board is a type of medieval cardboard. It is a by product of the paper industry. It can be soaked in water and allowed to form a shape. This shape can then be covered in sugar paste. The paste dries rock hard, but is difficult to get to adhere to the paper.  This armature is not for strong structures as it has to sit undisturbed while the paste dries.

When these materials are used as armatures, they need t be sized. Sizing is a material that prepares paper or other porous surfaces like terracotta for painting. It reduces the surface’s tendency to absorb liquids. The secondary layer between the armature and the sugar must be sized or the paper will leech the liquid out of the sugar too fast. Paper will pull moisture from the environment, which will cause the sugar to crack and the armature to warp. Both of these things would be catastrophic to the overall piece. A simple solution of glare prevents the paper from moisture exposure, warping and has the added benefit of being food safe.

Bees wax was used as a base. It was hard to get the sugar paste to adhere to the wax. The paste had to be wet on one side, and then stuck to itself to seal. Of all the medium, this one was one of the easiest to work with. Though it would be very heavy if used to create a large free standing structure.

Plaster mesh
Plaster mesh is a great armature surface for working with sugar paste once it has been cured, roughed and sealed. This gives the sugar a surface to grip and avoids the leeching problem caused by the porous plaster. It is ideal to use with metal and creates the lightest structure of all the bases. It takes the lease amount of time to dry.

Plaster mesh when allowed to be compacted and used as a stand-a-lone base gains a lot of weight. On a large-scale structure this would require a number of people to move.

The first attempt at sugar application was directly to the sanded wood. The sugar would not stick. There was not enough grip to the under surface for the sugar to make a solid bind. It peeled off the form, like bad paint peels from a wall that has not been properly primed.

The second attempt came after priming the surface with paper mache. I knew that sugar could grip the paper form my earlier attempts with the metal armatures. However, the paper mache would not stick to the surface either.

The third attempt came after a rasp was taken to the entire form.  This process created an uneven surface in the wood. The sugar stuck, but when it was dry it would not stay in position. It slid off the form.

The fourth attempt was a combination of priming the surface with a tempera paint, a layer of paper mache sealed with glare, followed by the sugar paste. The surface of the sugar was a bit bumpy than it normal would be as there was only one layer of sugar. The sugar was “smoothed” by burnishing it with water while it was still pliable.

As a final experimentation, wood was sanded with rough grit paper. It was sealed with glare and allowed to dry to a semi-tacky state. Sugar paste was rolled thin and water was brushed onto the surface to create a semi-tacky surface. These two tacky surfaces were then pressed together to create a bond. The sugar stayed in place to dry against the form. The dried sugar has bonded to the surface and remains in tact. The form was allowed to dry in position and sugar has created a hard shell and was able to be sanded. This could be further decorated with an additional layer of thin paste to create intricate details.

Pure paste, the control
The final display is ½” thick pure paste. It was molded in a form and has been allowed to dry.  Each of the armature experiments brought to this event were started 4 days ago. The pure paste is still soft in the middle. This takes the longest to dry and uses the most amount of paste of all the options. There is more paste in this shape than there is on the wood form. The paste on the other armatures has been rolled thin enough to see my kitchen counter through. Sugar in the 16th century was an expensive commodity. I try to use as little as possible.

Perferred armature
At the end of the experimentation, my preferred armature configuration for large structures is wire mesh, tied with silk floss, covered in plaster mesh and sized with glare. It gives me the lightest and most stable of base materials. For smaller molded pieces, I like the bees wax.

[1]“MSDS :: Calcium Sulfate (Plaster of Paris).” Educational Science Supplies, Toys, Games and Kits. Science Stuff, Inc., 1 Sept. 2006. Web. 26 Jan. 2012

The arte of comfetmaking- Part 3

Ragged comfits are made in a similar fashion as smooth comfits. The difference is the decoction* of the sugar. In the case of comfits the decoction comes in the saturation of sugar to water as the syrup is cooked to a higher temperature.

Georg Flegel Bread and Confections
Georg Flegel Bread and Confections

In Part 1 and 2, I illustrated smooth comfits. These were made with syrup that had been taken to thread state, 225° F. To make ragged comfits, I brought the temperature up to Manus Christi height (firm ball state 245° F). Since there was no modern care for the prevention of crystallization, the sugar did what was expected of it when agitated. It crystallized. It is the drying of this crystallized sugar that gives the comfit its ragged appearance. It takes less time and few coats to get a larger coating of sugar, than it does with the smooth comfits. The down side is you are working with a warm wok and sugar that is coming off the spoon somewhere in the 240 range. The risk of burning bare hands is great. I used a wooden spoon to make these as the temperature was too hot. When they cooled down enough, I worked at getting the cloves separated and dried with my hands.

Ragged Cloves- Sweet, with a bit of a bite. 1/2 of one is probably good for the modern palette. Or a whole one if you like clove.

* A decoction has one or more crude drug bases, either whole or suitably prepared that was boiled with water for a specified time. The object of a decoction was to produce an aqueous solution containing soluble active drug principles that were not degraded by heat. Pharmaceutical Compounding and Dispensing, by John F., Ph.D. Marriott, Keith A, Ph.D. Wilson, Christopher Andrew Langley and Dawn Belcher

Height of manus Chriſti

Manus Christi, or “the hand of Christ”, was a confection used as a preventative, similar to a vitamin. There are many different recipes some which include crushed pearls, cinnamon, flower essence, gemstones, gold and silver leaf.1 In the 16th century Manus Christi was a delicate crystallized sugar wafer, flavored with rose water. But more importantly, Manus Christi was a stage for boiling sugar. Many apothecary and confectionery recipes tell the user to boil sugar to Manus Christi height.

To make Manus Christi
Take halfe a pound of refined Suger, and some Rose water, and boyle them together, till it come to sugar again, then stirre it about while it be somewhat cold, then take your leaf gould, and mingle with it, then cast it according to art, That is in round gobbetts, and so keep them.
-A Closet for Ladies and Gentlevvomen: Or, the Art of Preseruing, Conseruing, and Candying ; with the Manner Hovve to Make Diuers Kinds of Syrups, and All Kind of Banqueting Stuffes : Also Diuers Soueraigne Medicines … London: Printed for Arthur Iohnson …, 1602. Print.

Technical notes- for Manus Christi confection
The most ideal texture and temperature to cook the sugar is to a firm ball. At the “soft ball stage”, the sugar takes longer to crystallize and it doesn’t set up into a wafer very easily. It is also prone to re-hydrating from moisture in the atmosphere and becoming sugar sludge. At the “hard ball stage”, the sugar crystallized very quickly and sets up too quickly. You have to pour the sugar while it is still quite hot and you do not get a smooth slick surface to the candy. The sweet spot appears to be “firm ball”, the stage right between the two. There is only 15 degrees between soft and hard ball stages and the sugar will progress through these 3 stages pretty quickly. At 245° F the heat should be killed and the pot removed from the stove. This produces a very smooth candy, with a fine grain crystal. It should dissolve on the tongue producing a slight effervescence mouth feel.

Manus Christi height- sugar stage
There are conflicting opinions of what the Manus Christi height actual is in modern temperatures. Some believe it is the blow/thread state of 225° F. If you bring the sugar only to this height for making the confection, you end up with several of the problems listed above. There are others that believe, if you heat the sugar 20 small degrees is enough to change the chemistry, into a more structured sugar. This is the temp that I use for my Manus Christi height. I find that I get a better, more consistent result in my confections with both modern refined and non-modern refined sugars.

Why is this distinction important? Well, in the case of comfits those 20 degrees is the difference between a smooth comfit and a rough comfit. That has everything to do with sugar concentration and crystallization than actual comfit making technique.

The arte of comfetmaking- Part 2

Sir Hugh Plat: Delights For Ladies
54. The art of comfit making, teaching how to cover all kinds of seeds, fruits or spices with sugar.

“At the first coate put on but one halfe spoonfull with the ladle, and all to move the bason, move, stirre and rubbe the seeds with thy left hand a pretty while, for they will take sugar the better, & dry them well after every coate. Doe this at every coate, not only in moving the bason, but also with the stirring of the comfits with the left hand and drying the same: thus dooing you shall make great speed in the making: as, in everie three hours you may make three pounds of comfits. And as the comfits doe increase in greatness, so you may take more sugar in your ladle to cast on. But for plaine comfits let your Sugar be of light decoction last, and of a higher decoction first, and not too hote.”

Let your sugar cool slightly, like 2-3 minutes. It’s 225 degrees. Ladle 1 table spoon at a time. I like to drop mine into the wok from at least arm height up. This will cool the sugar slightly so it can be handled.
Ladling sugar 1 table spoon at a time

Stir. Remember the sugar is hot and your pan should be warm. If you cannot hold onto the pan with your bare hand as you stir, your pan is too hot. The sugar will make the seeds stick together. Keep stirring. I like stirring with the back of my hand.
sticky seeds

As you stir, the coating will dry and the seeds will separate.
nearly dried

“When your comfits bee made, set your dishes with your comfits upon papers in them before the heat of the fire, or in the hot sun, or in an Oven after the bread is drawne, by the space of an houre or two, and this will make them very white.”

When your seed have sufficient coating, put them on a sheet pan to dry. I put mine on the radiator. The sugar will turn whiter as it dries. You can see what just a little bit of sugar over many coats will do to a comfit.
Finished comfits

Part 3- smooth vs rough comfits, on the morrow.

The arte of comfetmaking- Part 1

Sir Hugh Plat: Delights For Ladies
54. The art of comfit making, teaching how to cover all kinds of seeds, fruits or spices with sugar.
“First of all you must have a deepe bottomed bason of fine cleane brasse or latton, with two eares of Iron to hand it with two severall cordes over a bason or earthen pan with hote coales. You must also have a broad pan to put ashes in, and hot coales upon them. You must also have a cleane latton bason to melt your sugar in, or a faire brazen skillet. You must have a fine brason ladle, to let run the Sugar upon the seedes. You must also have a brasen slice, to scrape away the sugar from the hanging bason if neede require. Having all these necessarie vessels and instruments, worke as followeth.”

A modern set of tools includes a wok, gas stove, and a gravy ladle.  The wok is shallow enough you can get your hand in to work, heats evenly and retains heat so you do not need to be working over live heat. A gas stove allows for better temperature control, though this can be done via electric, but you need to watch out for scorching. If you do not  have a gravy ladle, and deep bowl spoon, that can handle a tablespoon of melted sugar.

“Choose the whitest, finest and hardest Sugar, and then you need not to clarifie it, but beate it onlie into fine powder that it may dissolve the sooner. But first make all your seeds very cleane, and dry them in your hanging bason.”

I use a small batch artisan refined loaf sugar. The Grocer that created the sugar is using an 18th century refining processes. This is as close to period refined sugar I am able to purchase. It has a larger sugar crystal structure and has a harder texture. It also has a noticeably different taste than modern granulated sugar. One thing that needed to be done was breaking the cone into small chunks prior to dissolving. The resulting sugar has a grittier texture than modern sugar. This loaf was shaved into pieced and then ground to a finer powder for better dissolving. I did not need to refine the sugar as it is already double refined. But I did have to skim the scum off of the boiling syrup. I ended up loosing .25 lbs from my end product, due to impurities.

“Take for every two pounds of sugar, a quarter pound of annis seeds, or coriander seeds, and your comfits wil be great enough, and if you will make them greater, take half a pound more of sugar, or one pound more, and then they will be faire and large. And halfe a pound of Annis seeds, with two pounds of sugar will make fine small comfits. You may also take a quarter and a halfe of annis seeds, and three ponds of sugar, or halfe a pound of annis seeds and foure pounds of sugar. Do the like in Coriander seeds.”

I am only doing a small batch of 1 cup of coriander seeds.

“Melt your sugar in this manner. Put three pounds of your powder sugar into the bason, and one pinte of cleane running water thereunto, stirre it well with a brasen slice, untill all be moist and well wet, then set it over the fire, without smoke or flame, and melt it well, that there bee no whole gristie sugar in the bottome, and let it seeth mildely, untill it will streame from the ladle like Turpentine, with long streame and not drop, then it is come to his decoction, let it seeth no more, but keep it upon hote imbers that it may run from the ladle upon the seeds.”

I am doing a small batch of sugar syrup, 1 lb of sugar loaf to 1 cup of water.

“To make them speedily. Let your water be seething hot, or seething, and put powder of Sugar unto them, cast on your Sugar boiling hote: have a good warme fire under the hanging bason. Take as much water to your sugar, as will dissolve the same. Never skim your sugar if it bee cleane and fine. Put no kinde of starch or Amylum to your sugar. Seeth not your Sugar too long, for that will make it black, yellow or tawnie. Moove the seeds in the hanging bason as fast as you can or may, when the sugar is in casting.”

Tip 1: Set on a really low boil. This is IMPORTANT. Low. Boil. The impurities in the sugar loaf make it boil over on anything other than low.

Tip 2: Skim the scum. I know the paragraph above says don’t do this if the sugar is fine. My loaf has impurities. I do not want any to be in your final product. With a modern sugar, you skip this step.
initial boil   Impurities

Tip 3: Use a candy thermometer until you are comfortable with what sugar looks like, sounds like and behaves at various stages. Sugar undergoes chemical and structural changes at the various stage points. It will often keep boiling at a specific temperature until the chemistry changes and then it will move up to the next state.

Water boils at 212. Your sugar pot should look like this: tightly controlled bubbles, violent boil. It will stay here for a while.
212 degrees

Thread state is 225. You sugar pot should look like this: bigger bubbles, less violent boil. The sugar bubbles should start having “form.
225 Thread

Tip 4: Make yourself comfortable. The rule of thumb is it will take 3x longer than you think it will. It will either boil over or go past the stage you are looking for if you are not watching. 1 lb of loaf sugar takes me about 50-60 minutes to get to thread stage.

Tip 5: Do not rush. No one likes scorched, burnt sugar. The smell will linger for days. And you do not want to make friends with your local FD.

Tip 6: People in period did not care about crystallization. It is not important to water down the sides of the pot during cooking, as you find in modern candy recipes.

The final syrup will look like this.
Part 2- making the comfits, on the morrow.

Gumme and dragant

Gum tragacanth, also known as gumma dragantis and gum dragon, is a sticky extrude of a family of plants belonging to the genus Astragalus. This plant family grows in the Middle East. By the 1300s, gum tragacanth was an article of commerce in Europe. Just as with sugar imports, gum tragacanth’s main entry point into the rest of Europe was via Italy. [1] It is also one of the ingredients that the Grocers had the power to garble and examine.

The type of plant from which the gum is harvested dictates the type and usage of tragacanth. The sweeter, whiter ribbon tragacanth or “maftuli,” was employed in pharmaceutical mixtures and confections. The bitter, less clear flake tragacanth or “kharmony, ” was employed in textiles, leather working, paper making and gilding. The point in the harvest cycle when the gum is collected generally determines the grade.

The terms ribbon and flake refer to the way the gum looks during the extrusion process. Gum production begins through a cut in the tap root. As the gum is harvested, the quality of the ribbon degrades. It is a seasonal product. Much of the harvesting occurs in June and runs through the start of Autumn. It is viscous, odorless, tasteless and water-soluble. These are the qualities which make it an excellent binder.

[1] Gentry, Howard. “Gum Tragacanth in Iran.” Economic Botany 11.1 (1957): 40-63. JSTORE. Web.