Complex sentence: After leaving Westminster School, he was apprenticed, in 1802, to his brother, an apothecary, with the view of adopting the profession of medicine, but his will was bent was towards chemistry, a sound knowledge of which he acquired in his spare time.
Split into simpler sentences: After leaving Westminster School, he was apprenticed, in 1802, to his brother, an apothecary, with the view of adopting the profession of medicine. However, Brande's bent was towards chemistry, a sound knowledge of which he acquired in his spare time.