Experiment with 10% Salt Solution

We mixed 200g of salt and 2 litres of pure tap water. We expected that this solution should have completely different features than clean tap water. Our hypotheses were right. The heat was cumulating in the lower side of the device. It seemed like the heat was dissipating. Suddenly, there was a large bubble with high temperature floating 10 cm up to the measuring cylinder. It had mixed with the solution around it and its temperature then dropped significantly. That repeated itself a few times as you may clearly see on the final screenshot. In some moments, the temperature differences were almost 80 ^oC on 30cm high of the measuring cylinder. In conclusion, we would like to add that the salt solution may be used like the perfect thermal insulator but sometimes heating the solution may be very dangerous.