What northern Italian cities became very wealthy through trade and why? (during the Renaissance)

Northern Italy was not richer in resources than many other parts of Europe, the level of development, stimulated by trade, allowed it to prosper. In particular, Florence became one of the wealthiest cities in Northern Italy

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.

buildings sir and respect