Electric capacitors are a modern way of storing electrical charges. Some modern capacitors are complex and difficult to build, but its predecessor, the Leyden bottle, is easier to make. Building a Leyden bottle is a great way to understand static charges and basic circuit concepts. You can load and unload the bottle over and over again to experiment with different materials and loads.
Steps
Method 1 of 3: Build a Leyden Bottle

Step 1. Choose a bottle
You need to be careful about the materials you use to build the Leyden bottle. The material must act as an insulator between the inner load (+) and the outer load (-). Choose a plastic bottle or a glass jar with a lid.
If possible, find a large bottle or jar, such as 2.5 to 1 gallon (2 to 4 liters) capacity

Step 2. Put aluminum foil inside the bottle
There will need to be a conductive material inside the bottle to be able to charge it. The traditional thing was to use water inside the bottle. If you want to build a more modern Leyden bottle, you should line the inside of the bottle with a sheet of metal (aluminum foil, etc.). The conductive material will acquire a positive charge when charging the Leyden bottle.
Press the aluminum foil against the sides of the jar, making sure it covers the entire circumference

Step 3. Insert an electrode into the cap
There will need to be an electrode sticking out of the bottle to charge the inside. To do this, you can hammer a nail through the cap of the bottle. Take care that the nail is pushed far enough into the bottle to make contact with the conductive surface (i.e. the aluminum foil) inside the bottle.
You can also attach a chain or other conductive material to the nail and let it hang down and touch the inner conductive surface
Step 4. Wrap aluminum foil around the outside of the bottle
The aluminum foil should wrap completely around the bottom half of the bottle. The aluminum foil on the outside of the bottle should not come in contact with the aluminum foil on the inside. The outer foil will have a negative charge relative to the inner foil.
Method 2 of 3: Load a Leyden Bottle

Step 1. Tape a styrofoam cup to a tart pan
The styrofoam cup will act as an insulator, allowing you to lift the cake pan without touching it. This will be important in order to load the Leyden bottle effectively. Tape the glass upside down to the center of the inside of the pie pan using masking tape.
The mold acts as an electroporous or charge carrier

Step 2. Get a foam plate
You will be using the foam plate because foam is an insulator. By adding and removing electrons from the foam, the charge will not shift. Instead, the foam will retain its charge until it dissipates from things like moisture in the air.

Step 3. Rub the foam plate with wool
Rub wool against the foam plate to deposit electrons on the plate. The foam attracts the electrons from the wool and they "stick" to it. This causes the foam to have a negative charge.
You can buy a small piece of wool at a fabric store

Step 4. Touch the cake pan with the foam plate
Lift the cake tin by touching only the styrofoam cup. Rest the mold on the foam plate. In this way, the negative charge on the foam plate can be pushed against the electrons in the cake pan.

Step 5. Touch the tart pan with your finger
Tapping the pan creates a path for the electrons in the pie pan to move away from the electrons in the polystyrene. This is because all electrons have a negative charge and therefore repel each other. When you touch the mold, you will likely see, hear or feel a spark. This is the result of electrons moving from the pie pan to your finger, leaving the pan with a positive charge.
Step 6. Tap the nail with the pie pan
Tapping the positively charged mold with the nail through the bottle cap removes electrons from the inner electrode (the nail and the conductive material inside the bottle). This balances the charge on the pie pan, but leaves a positive charge on the inner electrode. Be careful to hold the bottle by the outer electrode (the aluminum foil on the outside of the bottle) and not to touch the inner electrode with anything other than the cake pan (for example, your finger).
- You can repeat the procedure several times to develop a more powerful charge in the Leyden bottle.
- As the electrons travel from the inner electrode to the pie pan, you will likely hear or see a spark.
Method 3 of 3: Download the Leyden Bottle

Step 1. Place one hand on the aluminum foil
If you place a hand on the outer electrode, you create a bridge to the surface that is negatively charged. Be careful not to touch the inner electrode or any other live surface. No spark or charge movement will occur if you touch only the outer electrode.

Step 2. Hold hands in a circle
If you are going to do this experiment as part of a group, everyone should hold hands in a circle. The first person in the circle should hold the Leyden bottle and only be in contact with the outer electrode with one hand. With her other hand, she should hold the hand of the person next to her. The last person in the circle will only hold one hand. Everyone else will hold the hands of the people on either side.

Step 3. Touch the nail
After everyone in the group is holding hands and one person touches the outer electrode, the last person in the circle should touch the inner electrode with their finger. Once you place your finger on the nail, a circuit will be created that will allow electrons to travel from the negatively charged outer electrode to the positively charged inner electrode. Everyone in the circle should feel an electric shock and a spark may be seen or heard.
If you are building the Leyden bottle on your own, touch the outer electrode with one hand and the inner electrode with the other to discharge it. As you do so, you are likely to see, hear, and feel a spark
Advice
- Take care that the entire appliance is dry.
- It is possible to give a positive charge to the outer electrode instead of the inner electrode and observe similar results.
Warnings
- Make sure to thoroughly understand Leyden bottles if you intend to make a large bottle, as they can store enough electricity to kill you.
- You must be extremely aware and be very careful in case you have any medical equipment that is sensitive to electromagnetic currents (pacemakers, insulin pumps, etc.).