History of medicine : Part 6

1700 – 1900: 18th and 19th centuries

 

The industrial revolution of the 18th and 19th centuries saw a massive change in the way people lived and how this affected their health. People moved from small villages and an agricultural lifestyle to live in towns and cities that sprang up around the new factories, where they could work. People lived in dirty, overcrowded conditions with poor sanitation and dirty drinking water. Many died from diseases such as cholera, tuberculosis, measles and pneumonia – infections that could spread quickly and easily in these conditions.

Two of the big medical advances of this time were:

• vaccinations
• X-rays.

 

A microscopic revolution

People’s understanding of the body increased tremendously and finally dispelled ideas that had remained from ancient Greek times. Scientific knowledge spread rapidly because scientists began to publish their work in books. A Dutch clockmaker, Anton Van Leeuwenhoek, made one of the earliest microscopes to use a glass lens. The detail the revolutionary microscopes could see allowed the English scientist Robert Hooke to observe cells for the first time. In 1661 the Italian scientist Marcello Malpighi identified capillaries which finally showed the link between arteries and veins and proving Harvey’s theory for the circulation of blood.

 

Medicines comes of age

Medicine also made great advances during this time. Edward Jenner pioneered the earliest vaccinations and discoveries by Louis Pasteur and Robert Koch led to the understanding that infections were caused by certain bacteria or germs. The study of microbes, or microbiology, was born and the increased knowledge of pathogenic microbes led to the development of new medicines to tackle infectious diseases. The pharmaceutical industry was born.

The ideas of an earlier physician,Thomas Sydenham, were applied and this led to a great advance in the treatment of patients. He recognised the importance of detailed observation, record-keeping and the influence of the environment on the health of the patient.

The importance of hygiene

Perhaps the most famous nurse ever, Florence Nightingale, worked in a military hospital during the Crimean war. Conditions were poor and 80% of soldiers died from infections they caught in the hospital rather than their original wounds. Florence Nightingale improved standards of hygiene and sanitation which dramatically reduced the infections in her hospital. When she returned from the war, Florence Nightingale embarked on a campaign to modernise and improve hospitals. She set the foundations of hospital design and nursing practice that are still seen today.

 

Under the surgeon`s knife

Surgery also made great advances. Industry could produce better surgical instruments and operations were often performed in open theatres with interested members of the public invited to view them. There were no anaesthetics and surgeons prided themselves in the speed with which they operated; just a few minutes for a leg amputation. From the 1840’s onwards, the discovery of the anaesthetics ether, chloroform and cocaine allowed surgeons to take more time and care over operations. Modern anaesthetics mean that operations lasting several hours are now commonplace.

 

Antiseptics

Joseph Lister realised that infections caught during an operation often lead to death by septicaemia. He pioneered the use of carbolic acid as the first antiseptic to clean wounds and surgical instruments. Operations were performed with a fine spray of carbolic acid passed over the patient to kill any microbes in the air. In one Newcastle hospital, use of Lister’s antiseptic technique reduced deaths from infection from nearly 60% down to just 4%.

 

Vaccination

 

Smallpox was a killer disease in the 18th century. Infected people would become covered in horrible skin sores and often die a painful death. Those who recovered were left with terrible scars or poc marks on their skin. We now understand that it is caused by a virus (the variola virus). It infects the internal organs, causes severe blistering of the skin and death due to blood poisoning or secondary infections.

 

Kill or Cure

Edward Jenner is credited with the development of vaccination but in fact it was first introduced into England by Lady Mary Wortley Montagu in 1721. She tried a method that was used in Turkey where people deliberately infected themselves with a mild form of smallpox. This was the first form of innoculation. Sadly, many people died from the smallpox they were using to protect themselves. Clearly something different needed to be done.

 

Observation and vaccination

Jenner was a doctor who worked in Gloucestershire and the great advance he made was to notice that individuals who had contracted cowpox (the cow’s equivalent of smallpox) rarely caught the deadly human version. In 1796 he deliberately infected an eight year old boy called James Phipps with the pus from a cowpox sore. The boy became ill with cowpox but recovered. He then infected him with the normally deadly smallpox. As Jenner had predicted the earlier infection with the cowpox actually protected the boy who never caught smallpox. The practice of modern vaccination was born.

 

Cowpox VS smallpox

After many more successful vaccinations, Jenner published his results in 1798. However, they were met with scepticism and many doctors still carried out the more dangerous practice of innoculation with live smallpox pus. It was not until 1840 that this dangerous practice was banned and in 1853 vaccination by Jenner’s method was made compulsory. Protestors argued against compulsory vaccination, saying that it limited their personal choice; a similar debate to the one raging today over the MMR vaccine.

 

Understanding the immune system

When Jenner tried his first vaccinations, the way microbes cause infectious diseases was not understood and he did not know about the immune system. We now understand how vaccination works.

Pathogens are microbes that cause disease. These can be viruses, like smallpox, or bacteria. If a small amount of the weakened, or inactive microbe is introduced into the body it stimulates the immune system to produce antibodies to fight off the disease. The immune system remembers the microbe and can defend the body against any live form of the microbe that it may encounter in the future. The person is said to be immune to the disease.

 

Eradication of smallpox

Nearly 200 years after Jenner’s discovery, a programme of vaccination by the World Health Organisation (WHO) was started with the aim to completely eradicate the smallpox virus. It is estimated that smallpox killed 500 million people worldwide during the last century. The last case of naturally-transmitted smallpox was reported in Africa, in 1977. In 1980, the WHO officially announced the end of smallpox. There remain two highly-guarded stocks of the virus in laboratories in the USA and Russia. These are preserved for research purposes. Some authorities speculate that other laboratories have stocks that could be used in germ warfare but these claims are yet to be proven.

Jenner’s discovery has led to a greater understanding of the human immune system and vaccination programmes against diseases such as measles, mumps, polio and tuberculosis have improved the health of millions who need not fear these killer diseases.

 

X-rays – the start of medical imaging

 

X-rays were discovered in 1895 by the German Physicist Wilhelm Roentgen. He was studying cathode rays produced by a recently-invented piece of equipment called a Crooke’s tube when he noticed that a fluorescent screen across the room started to glow.

 

The start of medical imaging

The glow appeared to be caused by some unknown rays coming from the Crooke’s tube. He tried to block these rays with cardboard but found that they passed straight through it. Amazingly, if he put his hand between the tube and the screen, he could see an image of the bones in his hand. He named this new radiation X-rays and immediately realised how important his discovery would be to the world of medicine.

We are now familiar with atoms, protons, neutrons and electrons but when Roentgen discovered his mysterious rays the structure of the atom was unknown. For this fantastic discovery, Roentgen received the first Nobel prize in Physics in 1901.Today, the use of x-rays is common in hospitals and dentists all over the world.

 

X-rays

We now understand X-rays to be part of the electromagnetic spectrum with a very high energy and short wavelength.

Their high energy means that X-rays can pass through skin and muscle. They are absorbed by dense tissues like cartilage and bone. This produces an image on photographic film which can show damage hidden to the naked eye.

 

Modern Scanners

A modern development of the X-ray is found in CT scanners. Computerised tomography (or CT) scanners use several beams of X-rays simultaneously from different angles. Detectors measure the amount of each beam that is absorbed in the body and the data is fed into a computer that can build up a virtual, three-dimensional model of the area being examined. CT scans are very sophisticated and can be used to look for damage in much more than bone. They are often used to plan complex surgery and locate tumours before radiotherapy.

 

From cancers to airport check-in

X-rays can be used to treat disorders like cancers. In this case, a radiotherapist carefully calculates the dose of X-rays targeted onto the tumour inside the body. These X-rays are over 150 times stronger than those used to in X-radiographs and kill the cancer cells in the tumour.

Low energy X-rays are now widely used to see inside baggage in airports and other areas where security is important.