Sever 11 was exceedingly well filled last night to listen to the fifth of the interesting series of lectures on the human system. The doctor took up the subject as announced, and held the attention of his audience very satisfactorily to the end. Excuse must be made for the action of a few men, who rather rudely left before the lecture was over, on the ground of the examinations.

Dr. Farnham took up the subject of the influence of exercise on the digestive organs. He said that it promoted circulation of the food, respiration, and assimilation of the food. He said he accepted Lord Palnerston's saying as good, - "That the best care for the inside of a man was the outside of a horse." He further said that the mind was greatly refreshed when the body was moving at a rapid rate through the air as riding, driving, sailing or coasting. Boxing he considered good for digestion.

Dr. Farnham gave a long and intricate description, illustrated by diagrams, of the action of the heart and the circulation of the blood. The size of an average man's heart was about the size of his first, - generally larger, - and weighed about one pound in a healthy condition. The pulsation of a healthy heart was about 72 to the minute, but Napoleon's was never more than 40, and Sir William Congreve's never less than 128.

The heart consisted of a "right and left heart" joined into one, by a kind of muscular wall. This wall was sometimes lacking from birth, and owing to the imperfect circulation, people thus afficted turned a bright blue; this disease, cyanosis, is very apt to kill the sufferer in a few years. Having located the heart the lecturer proceeded to show how the blood going from the right auricle was passed into the ventricle and then sent travelling over the body. But ignorance of medical terms prevents our describing it at length.

The lecturer advised his hearers to think as little as possible about their hearts; that the heart of each man regulated itself according to his size, temperament, and occupation. He deplored the fact that many afflicted themselves with imaginary disease of the organ by firmly believing they were possessed with it. We will publish a synopsis of the next lecture as soon as possible.