Page:Popular Science Monthly Volume 80.djvu/125

Rh glass cases, greatly assisted by attached mechanical devices, helped the understanding of their structure and function.

The adult human body was, in its entirety and in parts, shown in the natural state, in the form of models, paintings, lumières and drawings, all displayed in the most artistic form and executed by artists of the first order, the high walls and high windows admitting a flood of light and rendering inspection thorough and easy. Mechanical devices were in operation for showing contraction of muscles; for explaining the action of the nervous system and the differences between mere reflex action and an action involving the cooperation of the higher nerve centers; for showing the circulation of the blood by a system of capillary glass tubes and the amount of work done by the heart; for demonstrating the function of the special senses and the mechanism of respiration and of voice and sound production. The subject of nutrition was given a prominent place. The more elementary chemical substances constituting the principal natural food products were shown in glass bottles and, further, shown by charts to which the percentage number of each elementary substance was attached, with the daily amounts of each required by man. Against a wall, there were arranged the quantities of water, salts, proteids, fats and carbo-hydrates which man consumed in a year and in the form of natural foodstuffs. At another table we were introduced into the mysteries of food adulteration and shown how cinnamon was made out of brick dust, pepper out powdered linseed oil-cake and strawberry syrup without strawberries.