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Chemical Revolution Essay

Chemical revolution involved the conceptual change which followed the development of the oxygen theory by Lavoisier that replaced the then popular phlogiston theory. Several factors contributed to this revolution including Priestley and Cavendish experiments, which proved that air is a mixture of gases rather than a single element as the then conventional understanding.

The improvement in communication of scientific findings increased public interest in chemistry and contributed to the replacement of the old concepts with new concepts.

This paper will examine the traditional scientific concepts including the much celebrated phlogiston theory of early 18th century and relate it with Lavoisier’s new approach. Initially, Lavoisier’s aim was to seek new interpretation of the existing concepts but his discovery led to replacement of the phlogiston theory.

The phlogiston theory was popular and universal in the 18th century and this limited the development of new concepts. However, Perrin notes that, “Lavoisier’s quest for reinterpretation of ideas built on concepts of earlier investigators; Boyle and Mayow, led to the oxygen theory” (54).

Phlogiston theory was a major achievement from the traditional theoretical principles since the phlogiston could be chemically established.

The starting point of chemical revolution involved the phlogiston theory, which held that combustion of substances released a phlogiston. This theory also explained the converse process of calcinations. The fact that the concepts of this theory were not a mere speculation but had experimental evidence, made the theory popular and universally accepted in early 18th century.

Even Lavoisier submitted to the universality of this theory before his experiments led to a new discovery. Towards the end of the 18th century, many substances were identifiable in laboratory and the new Lavoisier concepts led to the replacement of the phlogiston theory.

Get your 100% original paper on any topic done in as little as 3 hours Learn More Many factors contributed to the popularity of the phlogiston theory in the early 18th century. Before the phlogiston theory, it was believed that substances released the principle of inflammability when undergoing combustion and metals lost a metallic principle when undergoing calcinations.

Stahl experimentally identified the metallic principle and inflammability principles making his phlogiston theory popular. He was also able to make sulfur from its combustion products hence reversing the combustion process. Other concepts popular in the 18th century included the Etienne-Francois concepts regarding the reactivity of substances with each other and the rate of reactions.

Stahl developed the affinity tables where elements were arranged based on their reactivity which allowed a systematic study of reactions and identification of new elements.

However, some “British investigators led by Henry Cavendish and Joseph Priestley followed the isolation, identification of the properties and effects of the various components of air” (Perrin 71).

The major debate during this period especially in France revolved around the composition of air contained within bodies and its role. Some researchers believed that air was physically trapped within bodies while others argued that air is chemically combined in bodies like Gabriele-Françoise Venel.

Still others like Johann Theodor Eller held the view that decomposition produced the air trapped in the bodies. Nevertheless, in the midst of all these debates and ‘confusions’, Lavoisier’s experiments avoided the concepts of phlogiston theory and the affinity concepts laid down by earlier scientists.

Several factors contributed to Lavoisier’s success in coming up with new concepts to rival the phlogiston theory. His extensive reading of other scientists work coupled with inquisitiveness enabled him to note the differences between the findings and to design new experiments. He was also keen on the use of instruments to increase the accuracy of the results obtained from physical experiments.

We will write a custom Essay on Chemical Revolution specifically for you! Get your first paper with 15% OFF Learn More He was able to dispute the conventional hypothesis held by chemists that solutions of air made up vapor and instead proposed that an igneous fluid was responsible for turning water into steam. He opposed Stahl’s view that air cannot be compressed to fit into a specific body, by proposing that compressed air occupies less space.

Lavoisier used quantitative physical methods that were not employed by researchers of the time, which allowed him to obtain reliable and accurate results. He kept records and data collected from scientific experiments such as thermometer and barometer readings. In addition, he used quantitative methods involving weight measurements that allowed him to relate the weight of reactants and products in his experiments.

From earlier Lavoisier’s experiments, it is evident that use of quantitative methods and the earlier concepts concerning air allowed Lavoisier to develop the oxygen theory that immensely contributed to chemical revolution. However, his efforts at the start of his experiments were primarily to increase the understanding of the existing concepts rather than to replace them. Later, after more discovery and innovations he disputed the phlogiston theory causing a major conceptual change.

In 1774, Lavoisier studied the residue formed after combustion of mercury called the ‘red precipitate’. According McEnvoy, the phlogiston theory postulated that metals emitted a phlogiston during combustion leaving behind a residue (calx) (311). Lavoisier established that the red precipitate when heated decomposed into metallic mercury without the addition of charcoal as earlier suggested by Stahl.

This presented a serious limitation of the phlogiston theory since the phlogistons were not involved in the calcinations process. The developments in Lavoisier’s experiments presented many anomalies regarding the concepts of the phlogiston theory. In the beginning, the weight increase though experimentally established, could not be attributed to addition of air during combustion and calcinations.

Still, the phlogiston theory was still relevant since there were no alternative concepts to explain these observations. The emergence of many alternative concepts by Lavoisier that produced anomalous results to the phlogiston theory led to the development of an alternative theory to replace the phlogiston theory.

In producing the new theory, Lavoisier established experimental evidence in support of his new concepts, which at the same time attacked the older doctrines of Stahl. This phenomenon comes out clearly in the late 1770s when Lavoisier produced experimental evidence that disputed the concepts of phlogiston theory while increasing strength of his oxygen theory.

During the same period, Lavoisier and Laplace innovated methods of quantitative measurement of heat, which allowed them to estimate the specific heats released by substances undergoing combustion. Lavoisier was now able to include these findings into his oxygen theory making it more understood.

Not sure if you can write a paper on Chemical Revolution by yourself? We can help you for only $16.05 $11/page Learn More An important discovery by Lavoisier that triggered the chemical revolution was the discovery of oxygen gas. Other researchers like Pierre Bayen in 1774, were able to isolate oxygen by heating mercury oxide but identified it as carbon dioxide. Joseph Priestley also managed to isolate the same gas but identified it as nitrogen (Perrin 67).

However, in 1775, Lavoisier, isolated and identified oxygen gas. He further noted that the gas was one of the components of atmospheric air thus contradicting the earlier concepts that the atmospheric air is homogeneous. This among other discoveries was revolutionary in chemistry.

Works Cited McEnvoy, John. The Revolutionary Identity and the Chemical Revolution, 1993. Web.

Perrin, Chris. “Research Traditions, Lavoisier and the Chemical Revolution.” Osiris 2.4 (1988): 53-81.

Cannabis Dependence and Psychiatric Disorders: Outline Research Paper

Nursing Assignment Help Table of Contents Cannabis Dependence

Psychiatric Disorders

Cannabis Induced Psychiatric Disorders



The purpose of this study will be to examine psychiatric disorders that have been induced by overdependence on Cannabis. Cannabis Sativa is a herb originating from the Cannabaceae family that is recognised worldwide as a euphoric and hallucinogenic drug.

The strong smelling herb is used for medicinal purposes, for making hemp fibres and for developing recreational drugs (hashish and marijuana). The different parts of Cannabis have been used for different purposes and functions with one of the most common uses being for recreational purposes.

Marijuana is basically derived from the dried flowers and leaves of the cannabis sativa plant which is usually ingested or smoked while hashish is a resinous extract obtained from the plant which is usually vaporized or smoked (Elsohy, 2007).

Cannabis is one of the most famous recreational drugs in the world after caffeine, alcohol and tobacco where over 100 million people especially in the United States are consumers of the drug on an annual basis.

The reason for this is attributed to the fact that Marijuana which is derived from the Cannabis herb allows the user to be in a state of relaxation thereby reducing any cases of anxiety, paranoia or stress.

The tetrahydrocannabinol compound found in the leaves of the herb usually acts as the main stimulant once it is consumed by the user enabling them to experience a sense of peace and relaxation (Bolla et al, 2002). The drug however presents tertiary and secondary psychoactive effects that might pose a threat to the individual taking the drugs some of which include an increased heart rate, hallucinations, loss of memory, increased anxiety levels, high energy levels and an increasing sense of hunger.

If larger doses of the drug are taken through smoking, vaporization or oral ingestion, the effects might last longer for 24 hours where the consumer experiences both the secondary and tertiary psychoactive effects of the drug (Fusar-Poli et al, 2009). Marijuana is a very addictive drug which means that once it is consumed, it is very difficult to stop smoking or ingesting the drug because of the various effects that are presented by Cannabis.

Get your 100% original paper on any topic done in as little as 3 hours Learn More Cannabis Dependence Cannabis dependence is defined as a condition where an individual who continues to take Cannabis or Marijuana demonstrates cognitive, behavioural and physiological symptoms.

Based on the DSM-IV criteria for diagnosing substance dependence on various drugs such as the one understudy (Michael et al, 2004), cannabis dependence is determined by the existence of three or the following criteria which might occur within a period of 12 months.

Tolerance which is the first DSM-IV criteria explains Cannabis dependence to be the need that an individual has to consume large amounts of Cannabis Sativa so that they can achieve an increased level of intoxication that will lead to diminished thoughts, emotions or feelings on the part of the user (Michael et al, 2004).

The second criteria based on the DSM-IV criterion for substance abuse is withdrawal which explains Cannabis dependence to be a manifestation of withdrawal symptoms such as increased restlessness, insomnia or poor sleeping habits, increased appetite as the drug brings about hunger, irritability, paranoia and anger.

Other DSM-IV criteria that are used to explain dependence of marijuana is when an individual takes the substance in large amounts for a long period of time than was intended to relieve anxiety or stress, the individual experiences a persistent desire to reduce substance abuse but unsuccessfully fails to do so and/or they spend most of their time and resources trying to acquire the substance or drug which means that their social life and other recreational activities are abandoned because of the continued use of the drug (Wenger et al, 2003).

Based on the various studies that have been conducted on the dependence of cannabis, the drug has presented a less addictive potential when compared to hard drugs such as heroin, cocaine, tobacco or alcohol (Coffey et al, 2003). According to Michael et al (2004), Cannabis dependence has been cited as one of the clinical entities of substance abuse and dependence in the DSM-IV of mental disorders criteria.

The coding criterion that is used by the DSM-IV is usually based on the international classification of diseases where the signs and symptoms of diseases are identified and described in the various versions of DSM-IV textbooks. Based on the DSM-IV criteria, cannabis dependence falls under the category of substance related disorders as the individuals who consume the drug experience the various side effects that lead to cannabis dependence (Michael et al, 2004).

We will write a custom Research Paper on Cannabis Dependence and Psychiatric Disorders: Outline specifically for you! Get your first paper with 15% OFF Learn More To further explain cannabis dependence, the extended use of marijuana or hashish is likely to produce various changes in the bodily processes of an individual which affect how cannabis is absorbed or metabolized by the individual. These changes which are referred to as pharmacokinetic changes usually force the user to increase their dosage of the drug so that they can be able to achieve a desirable effect which is known as a higher tolerance to marijuana or Cannabis Sativa (Joy et al, 1999).

Higher doses of cannabis further reinforce the metabolism rate of the individual thereby increasing the rate at which the drug is broken down and expelled from the body. This means that Cannabis sativa, marijuana and hashish act as a system of reinforcement to the metabolic functions of an individual’s digestive system as well as their small and large intestines (Wenger et al, 2003).

According to Hall et al (2001), the risk factors of Cannabis dependence are usually determined by the number of doses an individual user takes in a day as well as the frequency of these doses. Based on their research, the authors determined that one in every ten people who consumed cannabis were more than likely to become dependent on the drug at some point in their life. People who consumed the drug frequently (five times in a day) were more than likely to increase their risk of developing dependence on the drug.

The risk factors that are considered to be the major contributors to cannabis dependence based on longitudinal studies conducted by Copeland et al (2004) include the frequent use of the drug especially at a young age where drug users who begin taking the drug during their teenage or adolescent years are at a greater risk of being cannabis dependent.

Coffey et al (2000) conducted a study in Victoria, Australia where they examined 2032 high school students to determine the impact that young age had on cannabis dependence.

The results of their study revealed that mid-school consumption of cannabis sativa was mostly associated with other factors such as frequent cigarette smoking, peer pressure from other students who are ingesting or smoking cannabis sativa and anti-social behaviour such as stealing, sexual promiscuity and violent tendencies.

Coffey et al’s (2000) study also revealed that the regular use of marijuana or Cannabis Sativa among young people at an early age continued to persist even as the adolescents approached young adulthood.

A follow up study conducted by Coffey et al (2003) of the high school students who had attained the ages of 20 to 21 years revealed that one in five the adolescent users of the drug demonstrated dependence to cannabis well into the early stages of adulthood.

Not sure if you can write a paper on Cannabis Dependence and Psychiatric Disorders: Outline by yourself? We can help you for only $16.05 $11/page Learn More Other risk factors that have been related to an increased risk of cannabis dependence include psychological distress where individuals use the drug to relieve feelings of distress, anger or sadness, poor parenting where children raised by parents who are cannabis consumers are more than likely to develop cannabis dependence in their teenage and adult years and influence from peers where children with friends who smoke or ingest cannabis are more than likely to consume the drug and also become cannabis dependent at an older age.

Ehrenreich et al (1999) from their study of cannabis dependence from a young age have concluded that there exists strong evidence that children who are exposed to cannabis or marijuana at a young age are more than likely to become cannabis dependent when they are older.

Psychiatric Disorders A psychiatric disorder which is otherwise referred to as a mental illness/disorder is a psychological or behavioural pattern that is usually associated to emotional distress or mental disabilities which an individual goes through. Psychiatric disorders are not part of the normal development of an individual and they are therefore termed as abnormal manifestations of the mental health of the individual.

Psychiatric disorders encompass very many mental health conditions which affect the behavioural, intellectual and cognitive abilities of an individual and some of these mental health conditions include anxiety disorders, personality disorders, sexual disorders, eating disorders, dissociative disorders and drug dependence disorders (Akiskal