The first ice calorimeter was developed by the French-Scottish physician Joseph Black (1728-1799), the French scientist Antoine Lavoisier (1743-1794) and the French mathematician and astronomer Pierre-Simon Laplace (1749-1827).
It was used to determine the heat released in various chemical changes. The calculations were based on the latent heat previously discovered by Black. These experiments meant the beginning of thermal chemistry. Lavoisier and Laplace discovered that the heat emitted by Guinea pigs in an ice calorimeter was approximately equal to the heat that would be produced in the same time period by the oxidation of the carbon equivalent to the heat released from the carbon dioxide produced by the Guinea pig. As a result, they established a relationship between direct and indirect calorimetry.
Valentin Hauy (1745-1822), an employee at the French Ministry of Foreign Affairs, started in 1784 a training center for blind masseurs. The aim was to provide the blind with an economic and social position, since he assumed that a blind person was better practiced in feeling and palpating muscles and therefore had a professional lead over 'sighted'.
With financial help of Duke Ernst II von Gotha (1745-1804), German theologian Christian Gotthilf Salzmann (1744-1811) (photo) bought the estate Schnepfenthal at the foot of the Thuringian Forest, where he started a philanthropic school where he himself gave the first physical education classes. From 1786 Johann Christoph Friedrich GutsMuths (1759-1839) took over that task.
The development of the ECG started with the discovery of electrical potentials in living tissue. This electromotive effect was first investigated by the Italian anatomist Aloysio Luigi Galvani (1737-1798). During his experiments he demonstrated that muscles can generate electricity. Galvani noted that dissected frog legs contracted when the rural nerves were stimulated with a metal scalpel. On September 20, 1786 he wrote:
"I dissected and prepared a frog in the normal way, and while doing something else, I placed it on a table where an electric machine was at some distance from its conductor and separated from it by an important space, when one of my assistants happened to touch lightly the frog's rural nerves with the tip of a scalpel, pulling all the leg muscles together, as if they had been affected by powerful cramps."
Later he showed that direct contact with an electric generator led to muscle contraction. Galvani also used copper hooks that were attached to the frog's spinal cord and hung from an iron railing in his garden. He noted that the frog legs contracted during thunderstorms, but also in good weather. He interpreted these results in terms of 'animal electricity' or the retention of 'neuroelectric fluid' as in an electric eel. Later he also showed that electric stimulation of a frog heart led to contraction of the heart muscles. Galvani also discovered that if one placed the nerve of a frog on the injured muscle of another frog, the muscles of the first frog contracted.
In 1786 Thomas Jefferson (1743-1826), the third president of the United States, claimed the invention of the pedometer. Because he never patented the device, it must be regarded as an historical speculation. The device was tied to the test person's belt and sometimes also called 'Tomish meter'. In order to measure the distance traveled, weighted metal balls within the device were swinging on a pendulum. The device was not very accurate, it only gave a rough estimate of the distance traveled.
The Irish physician Adair Crawford (1749-1795) built the first calorimetric breathing chamber for the simultaneous measurement of gas exchange and heat production.
Just like Antoine Lavoisier (1743-1836) Crawford used a space with three compartments (A). But unlike Lavoisier, he used water instead of ice, so the conditions in the calorimeter probably affected metabolism much less. A series of pots and bins (B, C, D) was successively emptied and refilled with water via valves T, U, and V, which moved the room air into the pots for analysis. The gas measurements with this device were not satisfactory
Together with the French physiologist Armand Seguin (1767-1835), Antoine Lavoisier (1743-1794) performed breathing experiments on humans at two different ambient temperatures, determining the first human basal metabolic values.
Not all details are known about the device, it is known that they used a face mask and that the exhaled air was collected and then analyzed for oxygen and carbon dioxide.
Modern science owes a lot to Lavoisier's experiments, especially in the field of gas exchange. In November 1790 he reported: