1. Models are analogies that allow us to clarify hypotheses—proposed explanations of relationships between causes and effects. What roles do models play in testing hypotheses? Models provide the physical testing and proof of a hypothesis by exploring the extent to which the two factors relate within the given hypothesis. It puts a theory into action, to see if the theory is correct.
2. What did the humoral model of disease propose as the cause for cholera? The humoral model of disease said that disease was caused by an imbalance in one or more of four "humors" or fluids in the body: blood, phlegm, black bile, and yellow bile. Physicians would decide on a treatment based on what they thought was the cause of the imbalance. There were treatments that included the act of "blood-letting" where they would either cut the person, and allow them to bleed for a short time, or apply leaches to them to remove blood.
3. What did the miasma model of disease propose as the cause for cholera? The miasma model of disease proposed that the cause for cholera was caused and spread from person to person through bad vapors or gases in the air. 4. Unlike Snow’s later work on cholera, his research on anesthesia was experimental in nature. What general skills of experimental design were necessary to plan effective experiments to test dosage measuring and delivery systems for anesthesia, or to investigate the properties and effects of different drugs? In order for Snow to plan effective experiments to test dosage measuring and delivery systems for anesthesia, or to investigate the properties and effects of different drugs, he had to first decide that he would no longer be a surgeon, but focus his time primarily on his anesthesiology practices. The fact that Snow built a lab in his home, and used “animal subjects” for his testing, and recorded these findings, helped him investigate the properties and effects of different drugs.
5. Why are experiments considered strong tests of hypotheses? Experiments are considered strong tests of hypothesis because they are what scientists use to test a hypothesis. The use of experiments can find out if a hypothesis is true or not. Experiments can also lead to a change in a hypothesis.
PART II QUESTIONS
1. What causes cholera, and how is it transmitted?
Cholera is caused by the contamination of water by means of bacteria from partially digested food, feces, or decaying matter. It is transmitted through a contaminated water supply. 2. Why weren’t Snow’s ideas about cholera accepted at this early date? Snow’s ideas about cholera was not accepted well at this early date, because scientists were skeptical back then, and had to have some kind of definitive proof. Also, they did not want to believe something that the scientific community did not condone or represent. 3. Explain why cholera outbreaks are more consistent with contamination of water than air. Snow had extensive experience with the use of gases, and none of which had any signs of relationship with the causes of cholera. Because of this fact, Snow knew it had to do something with the water supply. Cholera is a waterborne disease, it cannot be transmitted through the air.
4. Given that cholera outbreaks are more consistent with contamination of water than air, why did the miasma model persist? The miasma model persisted because that is what the scientific community has agreed upon is the cause, and anything else was just a theory that was shunned and thought negatively upon.
5. How did Snow’s experimental research on anesthesia help him design a new model for the cause of cholera? When Snow had experimental research on anesthesia with animals, he found that the properties of gases were in no way consistent with the belief that cholera was caused by bacteria in the air. This led Snow to design a new hypothesis with water being the cause of cholera.
6. Why would evidence of cholera in people living...