Introduction:

In 1866, E. Goldstein discovered a new type of radiation in a gas discharge tube, which he called canal rays. These rays were found to have a positive charge and eventually led to the discovery of a subatomic particle known as the proton.

Observation of Deflection:

Goldstein observed that when the gas discharge tube was subjected to a high voltage, the canal rays produced within the tube were deflected towards the positively charged electrode. This indicated that the canal rays themselves carried a positive charge.

Deflection by Electric and Magnetic Fields:

Further experiments conducted by Goldstein involved the use of electric and magnetic fields to study the behavior of the canal rays. When an electric field was applied perpendicular to the direction of the rays, the rays were deflected towards the positively charged plate. This deflection indicated that the canal rays were positively charged. Additionally, when a magnetic field was applied perpendicular to the direction of the rays, the rays were also deflected, further confirming their positive charge.

Comparison with Cathode Rays:

Goldstein also compared the behavior of canal rays with that of cathode rays, which had been previously discovered by J.J. Thomson. Cathode rays were found to be negatively charged and were deflected towards the negatively charged electrode. When the canal rays and cathode rays were simultaneously present in the gas discharge tube, their deflections in opposite directions provided evidence for their opposite charges.

Conclusion:

Based on these experimental observations, E. Goldstein concluded that the canal rays were positively charged. This discovery paved the way for further investigations into the nature of these radiations, eventually leading to the discovery of the proton as a subatomic particle. The study of canal rays and their positive charge played a crucial role in the development of our understanding of atomic and subatomic particles.