Magnesium sulfate

Magnesium sulfate (or magnesium sulphate) is an inorganic salt (chemical compound) containing magnesium, sulfur and oxygen, with the formula MgSO₄. It is often encountered as the heptahydrate sulfate mineral epsomite (MgSO₄·7H₂O), commonly called Epsom salt, taking its name from a bitter saline spring in Epsom in Surrey, England, where the salt was produced from the springs that arise where the porous chalk of the North Downs meets non-porous London clay. The monohydrate, MgSO₄·H₂O is found as the mineral kieserite. The overall global annual usage in the mid-1970s of the monohydrate was 2.3 million tons, of which the majority was used in agriculture.

Anhydrous magnesium sulfate is used as a drying agent. The anhydrous form is hygroscopic (readily absorbs water from the air) and is therefore difficult to weigh accurately; the hydrate is often preferred when preparing solutions (for example, in medical preparations). Epsom salt has been traditionally used as a component of bath salts. Epsom salt can also be used as a beauty product. Athletes use it to soothe sore muscles, while gardeners use it to improve crops. It has a variety of other uses. Epsom salt is also effective in the removal of splinters.

Epsom

Not to be confused with the camera manufactures "Epson"

Coordinates: 51°20′10″N 0°16′01″W / 51.336°N 0.267°W / 51.336; -0.267

Epsom (/ˈɛpsəm/) is a market town in Surrey, England, 13.6 miles (21.9 km) south south-west of London. The town straddles chalk downland (Epsom Downs) and the upper Thanet Beds. Epsom Downs Racecourse holds The Derby, now a generic name for sports competitions in English-speaking countries. The town also gives its name to Epsom salts, extracted from mineral waters there.

Epsom is the source of the Hogsmill River and includes the semi-rural Horton and Langley Vale.

History

Epsom lies within the Copthorne hundred used for periodic, strategic meetings of the wealthy and powerful in Anglo Saxon England, and later having a Hundred Court. The name of Epsom is early recorded as forms of Ebba's ham (home or perhaps manor). Ebba was a Saxon landowner. Many Spring line settlements by springs in Anglo-Saxon England were founded at the foot of dry valleys such as here and Effingham, Bookham, Cheam, Sutton, Carshalton, Croydon and Bromley. A relic from this period is a 7th-century brooch found in Epsom and now in the British Museum.

Salt

Common salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in its natural form as a crystalline mineral is known as rock salt or halite. Salt is present in vast quantities in seawater, where it is the main mineral constituent; the open ocean has about 35 grams (1.2 oz) of solids per litre, a salinity of 3.5%. Salt is essential for animal life, and saltiness is one of the basic human tastes. The tissues of animals contain larger quantities of salt than do plant tissues; therefore the typical diets of nomads who subsist on their flocks and herds require little or no added salt, whereas cereal-based diets require supplementation. Salt is one of the oldest and most ubiquitous of food seasonings, and salting is an important method of food preservation.

Some of the earliest evidence of salt processing dates to around 8,000 years ago, when people living in Romania were boiling spring water to extract the salts; a salt-works in China has been found which dates to approximately the same period. Salt was prized by the ancient Hebrews, the Greeks, the Romans, the Byzantines, the Hittites and the Egyptians. Salt became an important article of trade and was transported by boat across the Mediterranean Sea, along specially built salt roads, and across the Sahara in camel caravans. The scarcity and universal need for salt has led nations to go to war over salt and use it to raise tax revenues. Salt is also used in religious ceremonies and has other cultural significance.

Tree stump

After a tree has been cut and felled, the stump or tree stump is usually a small remaining portion of the trunk with the roots still in the ground. Stumps may show the age-defining rings of a tree. The study of these rings is known as dendrochronology.

Regeneration

Stumps (both those on the ground and stumps of removed branches) are sometimes able to regenerate into new trees. Often, a deciduous tree that has been cut will re-sprout in multiple places around the edge of the stump or from the roots. Depending on whether the tree is being removed permanently or whether the forest is expected to recover, this can be either desirable or undesirable. Stump sprouts can grow very quickly and sometimes become viable trees themselves either for aesthetics or timber, due to the existing root structure; however, the cut portion of the trunk may weaken the sprouts and introduce disease into the newly forming tree(s).

The process of deliberately cutting a tree to a stump to regrow is known as coppicing.