Science Buddies: "Ask an Expert"

For a project, I'd like to demonstrate one of Joseph's experiments, like how he found dephlogisticated air or perhaps an experiment on photosynthesis and how he was able to observe it. I was thinking of putting a lighted candle in a large container and seal it, then count the time of how long it takes for the candle to burn out. Then I would have another equally large container WITH a live plant + water, a lighted candle, and great lighting. I think the plant will make more CO2 and that means it would take longer for the candle to burn out.
The only problem is I don't know if photosynthesis is a fast or slow process.

Hi,

This sounds like a very interesting project. Here is a website that might provide useful information:

http://www.juliantrubin.com/bigten/oxyg ... ments.html

Unfortunately photosynthesis is not extremely fast I most situations. It involves a series of reactions, and some plants don’t do all the reactions all at once(I think some take both a light and a dark period to complete the cycle. Note tha Priestley waited 27 days to regenerate the oxygen in one of his experiments..

You may find this electronic copy of Priestley’s book “Experoments and Observations on different kinds of air” to be of interest:

http://books.google.com/books?id=gB0UAA ... q=&f=false

http://books.google.com/books?id=Azu4AA ... q=&f=false

Here is an overview of photosynthesis:

http://en.wikipedia.org/wiki/Photosynthesis

The history of science is fascinating. You should have a lot of fun doing this project!

Best regardss,

Barrett L. Tomlinson

THANKS FOR THE RESOURCES.

Based on it, would this experiment work.

A live plant with water in a small bowl and candle. Together those items are put in a large sealed container, I would then lit up the candle with concentrated sunlight and it should burn out all the oxygen. Then, in one-two weeks time, I will attempt to relight the candle that is in the sealed container with concentrated light. It should burn again, which demonstrates how Priestley observed plants affect "air".

Hi,

It sounds like an interesting experiment to try. Good luck!

Best regards,

Barrett L. Tomlinson

As I only have about 1 week of time, I was thinking of doing an experiment on how Joseph created Soda water. Is there a simple, time efficient way of mimicking what joseph have done ? The reason why I need to demonstrate one of Joseph Priestley experiment is for a project of mine.

Also, any suggestions on what else I could demonstrate that mimicks his works.