Sounds and Charrière: the rest of the story.

Parisian cutler Joseph-Frédéric-Benoît Charrière (1803-1876) contributed greatly to surgical disciplines with innovative tools, but his legacy is the gauge system he developed in 1842 that is still used for catheters, probes, and dilators. Sounding devices have been documented in the surgical armamentarium since 3000 BC, with practitioners such as Hippocrates, Galen, Celsus, and Al-Zahrawi espousing theories on sounding and the related topics of stones and urinary obstruction. The medical revolution in 19th-century Paris propelled technology and one of the most influential men involved was Charrière, who pioneered diverse technical processes in the manufacturing of surgical instruments, led one of the largest instrument manufacturing companies, and improved on tools introduced by predecessors including his mentor Guillaume Dupuytren. Most importantly he created the catheter scale that, despite not being favored in its country of origin, became an international standard and is known today as the French system. The classification of sounds, catheters, and bougies has undergone many variations throughout the years, but the French scale still holds in current medical practice as an accurate and nearly universal sizing tool.

An ancient relation between units of length and volume based on a sphere.

The modern metric system defines units of volume based on the cube. We propose that the ancient Egyptian system of measuring capacity employed a similar concept, but used the sphere instead. When considered in ancient Egyptian units, the volume of a sphere, whose circumference is one royal cubit, equals half a hekat. Using the measurements of large sets of ancient containers as a database, the article demonstrates that this formula was characteristic of Egyptian and Egyptian-related pottery vessels but not of the ceramics of Mesopotamia, which had a different system of measuring length and volume units.

Puerto del Pendulo, doubtful sound: la visita de la expedición Malaspina a Nueva Zelanda en busca de la verdadera forma de la tierra / Puerto del Pendulo, doubtful sound: the Malaspina expedition's visit to New Zealand in quest of the true figure of the earth

The Malaspina expedition was assigned the task of conducting a series of experiments using the pendulum to measure the strength of gravity at different locations during the course of its voyage.The immediate objective was to establish the length of a pendulum beating at seconds at latitude 45º as the basic unit of a new universal system of measures. Although the new unit, the metre, was eventually established on a different principle, the gravity experiments carried out by the expedition resulted in useful geodesic information and incidentally led to the first charting of Doubtful Soundin New Zealand (AU)

La expedición Malaspina tuvo por misión realizar una serie de experimentos utilizando un péndulo para medir la fuerza de la gravedad en los diferentes lugares recorridos durante el viaje. El objetivo inmediato consistió en establecer la longitud de un péndulo oscilando durante unos segundos a una latitud de 45º como unidad básica de un nuevo sistema métrico universal. Aunque la nueva unidad, el metro, fue finalmente establecida por otro principio diferente, los experimentos que llevó a cabo la expedición sobre la gravedad proporcionaron una información geodésica muy útil y por casualidad dieron lugar al primer trazado de mapa de Doubtful Sound, en Nueva Zelanda (AU)

J.-F.-B. Charrière: the man behind the "French" gauge.

Joseph-Frédéric-Benoît Charrière, a 19th century Parisian maker of surgical instruments, has by virtue of his ingenuity and advanced thinking, continued to have his presence felt in medicine throughout the 20th century. His most significant accomplishment was the development of a uniform, standard gauge specifically designed for use in medical equipment such as catheters and probes. Unlike the gauge system adopted by the British for measurement of needles and intravenous catheters, Charrière's system has uniform increments between gauge sizes (1/3 of a millimeter), is easily calculated in terms of its metric equivalent, and has no arbitrary upper end point. Today, in the United States, this system is commonly referred to as French (Fr) sizing. In addition to the development of the French gauge, Charrière made significant advances in ether administration, urologic, and other surgical instruments, and the development of the modern syringe.

Systems of measurement: their development and use in medicine.

A brief historical review of customary measurements, the resultant chaos and the desirability for a simplified unified measurement system is discussed. The basic units of the International System of Units are described and defined, along with their application in Medicine.

Metrication of clinical laboratory data in SI units.

The development and general concepts of the Système International d'Unités (SI units) are discussed. The basic and derived quantities and units of the SI used for clinical laboratory data are reviewed. Ranges of normal values for a number of body fluid constituents are given in the units in current general use and in SI units, with corresponding conversion factors.