After one frog's heart has been stimulated, an extract of fluid from that heart can make a second frog's heart beat faster. what conclusion did otto loewi draw from these results?

When one frog's heart is stimulated and the extract from this stimulated heart is transferred to the heart of another non-stimulated frog, the rate of heart beat of the second frog will be increased too because of the transmission of the impulses via the synapses. Hence, this observation proves that the transmission of the impulses at the synapses is a chemical event.