The origin of pencils
The origin of the modern pencil can be traced back to 1564 when a large graphite mine was discovered in Cumbria, England. People cut the pure graphite into sheets, then into square rods. The graphite rods were then inserted into hand made wooden holders. Because graphite looked like lead ore, they called it black lead hence the “lead” pencil. For a while the English had a monopoly of pencil production until a Frenchman patented a way of using graphite powder mixed with clay then baked. The hardness of the graphite varies by the ratio of clay to graphite. A pencil marked "HB" is hard and black; while a pencil marked "HH" is very hard. An alternative more widespread classification is to indicate the degree of hardness by numbers such as 2B, 4B (Softer) or 2H, 3H (harder). The best pencils are made in Germany, say the Germans. Even though it is possible to make synthetic graphite, a good pencil needs natural graphite.
Graphite is a form of carbon and can be considered the highest grade of coal, although it is not normally used as fuel because it is difficult to ignite. Unlike diamond another form of carbon; graphite is an excellent electrical conductor. Graphite is found within sedimentary rock within the earth’s crust. Sedimentary rock is a type of rock formed by the deposition of organic material that settle and accumulate into sediment. Sedimentary rock is found everywhere on earth but forms just 8 per cent of the total volume of the crust. Water, wind and ice move sediment and deposit it in certain areas so that sedimentary rock is found in layers, called beds or strata.
The study of the sequence of sedimentary rock strata is the main source for scientific knowledge about the history of life on earth and the earth’s history in general. The earth is now estimated to be at least 4.6 billion years old. Sedimentary rock is also an important source of natural resources such as drinking water, fossil fuels and mineral ores including graphite. For these organic compounds to be found, they must have been deposited there a long time ago. What we are harvesting today are plant and animal material from millions of years ago. So the organic material being produced today will be converted into sedimentary rock tomorrow. This is useful to know when we think about what we want our education system to produce.
In the health system when you say “Hb” then we think ‘Haemoglobin’ not pencil. Within the body, haemoglobin is the compound inside the red blood cells that carries oxygen. Almost all women who have visited a health facility know about their “Hb” because it is an important indicator of good health. There are many different types of haemoglobin. The most common are Haemoglobin ‘A’, which is found in adults. Newborn babies are born with high levels of Haemoglobin ‘F’ which is what the foetus uses while still in the uterus.
Haemoglobin ‘F’ has a very high affinity for oxygen and this is how the foetus is able to extract oxygen from the mother during pregnancy. Once born, Haemoglobin ‘A’ gradually replaces ‘F’. There are more than 400 abnormal types of haemoglobin. In our part of the world, Haemoglobin ‘S’ is not uncommon. Its presence is the cause of sickle cell disease. However the more common problem with haemoglobin is not the type of haemoglobin but the quantity within the body. This is mainly due to insufficient amounts of iron, which is needed to make haemoglobin.
Virtually every living creature needs iron to survive. For humans, beans, leafy green vegetables, red meat and whole grains are good sources of iron. The problem is not so much as intake as who you share your blood iron stores with. In the case of pregnant women it is the foetus that is sharing so often they need a boost to maintain levels. In the case of children it is worms in the intestines that are enjoying life. Being children you can imagine that their iron stores are small to begin with and they are growing rapidly. Iron deficiency anaemia occurs. People with anaemia feel weak, tire easily and have trouble concentrating. When the problem is not corrected early and quickly enough cognitive deficiencies can become permanent. Deworming children is a simple and effective way of preventing this.
If a child infested with worms is dewormed, their school performance improves. The dead worms excreted in stool are acted on by scavengers such as bacteria and eventually find themselves as part of the sediment. After millions of years they will be a part of the organic layer within sedimentary rock. So we have the opportunity, by paying attention to the health of our school children, to not only improve their school performance and their life in general but to produce ‘free’ graphite for making pencils in the future. Investing in health pays.