Why do we use alcohol lamps?

  

What is this all of a sudden?

Photo courtesy of Kenneth Co.

Yes! It's an alcohol lamp!

If you didn't know, don't be embarrassed. Because as the title suggests, alcohol lamps are now disappearing from science classes.

Why are alcohol lamps no longer being used in school classes?　This article will delve into the following three questions

What are the alternatives to alcohol lamps?

Why are alcohol lamps disappearing?

Do we need alcohol lamps?

What are the alternatives to alcohol lamps?

Experiments involving fire do not really make their appearance in today's science classes until the fourth grade of elementary school. Students learn about "state changes" such as solid, liquid, and gas, and "combustion" by heating and cooling water. Alcohol lamps have often been used for these experiments.

Recently, however, something else is replacing them.

A gas stove!

The cylinder is the same as that of a household cassette stove, but the stove itself is slightly different. The one for science experiments is one size smaller and has a net stand. It has an automatic fire extinguishing function when the cylinder becomes hot, and a knob that cannot be turned to light the stove unless it is set correctly.

Photo courtesy of Kenith Co.

Gas burners are also used as heating devices for experiments, but gas burners are more difficult to handle than alcohol lamps, so they are not often used in elementary schools to begin with.

In comparison, a gas stove is something that can be found in the home, and because of its heat power, it is much faster than an alcohol lamp or gas burner when it comes to boiling water. It also has the effect of shortening the time for experiments.

Why are alcohol lamps disappearing?

But even though they have a safety device, you might ask, "If the heat is so strong, wouldn't a gas stove be more dangerous?" Don't you think?

In fact, safety in science class is less about the strength of the flame and more about the way the flame is lit. And this is also why alcohol lamps are disappearing.

Specifically, there are three reasons

They are difficult to light.

They might explode.

It might ignite (and it is hard to notice). 1.

1. it is difficult to light.

Alcohol lamps are lit with a match. However, this match is difficult for children. According to a nationwide survey of children, about 60% of fourth-graders said they could not light a fire with a match (less than 20% of fifth-graders; the same is true of fifth-graders, who said they could not light a fire with a match). (National Institution for Youth Education, 2015). Another survey found that about 70% of parents living in the Tokyo metropolitan area with elementary school-aged children have never allowed their children to use matches (Zojirushi, 2015). For many children, it appears that science class is the first place they encounter matches. On the contrary, if a child comes from a family whose home is all-electric and uses an induction cooktop for cooking, lighting a fire by oneself is a special experience in itself.

However, the purpose of the class is not to light a fire. The goal is to observe the changes that occur when things are heated over a fire. Focusing attention on other things can be detrimental to learning. 

2. it might explode.

Even if you manage to light a fire, you still can't let your guard down. Although it is not widely known, alcohol lamps can explode. This is due to the nature of alcohol.

Alcohol is also found in disinfectants and alcohol, but that is ethanol. In contrast, the fuel for lamps is methanol. Although they are different, they are similar not only in name but also in properties. For example, when you pour rubbing ethanol on your hands, it feels cool and dries quickly. This is because ethanol easily changes from a liquid to a gas (vaporizes easily), and the same is true of methanol.

When gaseous alcohol mixes with oxygen in the air, it burns well. Alcohol lamps make use of this property.

However, if the amount of methanol in the lamp is low, the gaseous methanol will accumulate in the lamp body. If air gets into it, there is a risk of an explosion inside the lamp when it is lit. Since alcohol lamps are made of glass, any scratch or crack could cause them to explode. To prevent this from happening, it is essential to check the remaining amount of alcohol and the condition of the glass, which is a burden on the teachers. 3.

3. it might catch fire (and it is hard to notice).

And the most important thing to be aware of is "ignition," where the fire transfers to other objects. Alcohol lamps are so small that even a light bump with the elbow can cause them to fall over. If it should explode, you may not only be injured by flying glass but you may also be burned by the flaming methanol.

To make matters worse, methanol flames are not red inside, but light blue. Depending on the light, methanol flames may be difficult to see, and ignition may not be immediately apparent.

Thus, the dangers of alcohol lamps can be laid out in many ways. In fact, many serious accidents that have occurred in elementary school science classes have occurred during experiments involving heating operations (Kasuga and Morimoto, 2015). Although the risk of explosion or ignition is not zero even with gas stoves, gas stoves for science experiments have begun to spread, replacing alcohol lamps in textbooks because of their safety devices, resistance to collapse, and ease of lighting.

Is an alcohol lamp necessary?

Some of you who read this article may be wondering, "Are today's children safe if they cannot use alcohol lamps?" Some of you may be wondering, "Are children safe now if they cannot use alcohol lamps?

Is an alcohol lamp necessary or unnecessary?

To be honest, I don't think they are necessary. The safety of the child comes first, and even if the alcohol lamp cannot be used, there are other heating devices that are more convenient. Besides, the ability to freely use scientific knowledge such as "change of state" and "combustion" would be more applicable and useful in many situations than the skill to use an alcohol lamp. As evidence, the explosion and ignition of an alcohol lamp can be explained with the knowledge of "change of state" and "combustion" that elementary school students learn.

However, it is also considered that knowledge can be used only when it is accompanied by experience. Also, if they have fewer opportunities to use alcohol lamps, they will have fewer opportunities to use matches, which could be a problem in the event of a disaster.

References

Dainippon Kyoiku Kenkyujo (ed.) (2010) "Safety Manual for Science Observation and Experiments in Elementary Schools for the New Courses of Study," Revised Edition, Dainippon Books, p.74.

Hikima, K. (2011) "How to use an alcohol lamp," in Kato, N. and Hikima, K. (eds.), Safe Elementary School Science Experiments: Basic Operation Handbook, Toyokan Shuppansha, pp.60-61.

Kasuga, Hikaru, and Koichi Morimoto (2016), "A Study on the Trends of Elementary School Science Experiment Accidents in the Past 30 Years," Journal of Science Education, 57(1), pp. 11-18.

Zojirushi (2015), "Survey of Life Experiences of Imadori Elementary School Students," https://www.zojirushi.co.jp/topics/shougakusei.html (last accessed: 2017.09.15). (Link removed. URL may also be invalid).

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