- Scientists make observations
- Lightning is a kind of weather phenomenon
- Weather phenomenon can be observed
- Therefore, scientists make observations on lightning

- Scientists make observations on lightning
- Lightning is a kind of electrical discharge
- So, scientists make observations on electrical discharge in the form of lightning

Hence, scientists make observations on electrical discharge in the form of lightning
Early scientists most likely saw a discharge of electricity for the first time when observing a
- Scientists make observations 
- Lightning is a kind of weather phenomenon 
- Lightning is a kind of electrical discharge 
- Weather phenomenon can be observed