Natural families

Natural methods, ie, natural family planning, are methods based on awareness of the fertile and infertile segments of the menstmal cycle. This awareness can be utilized to avoid pregnancy or to become pregnant. 

By the mid-nineteenth century, approximately sixty-five elements were known When Graham planned a chemistry course in the mid-nineteenth century, he divided the elements into "groups or natural families," based on their properties he divided the metals into nine "orders" distributed among three "classes" (alkalis and alkali-earths metals of earths and metals proper, divided according to affinity for oxygen).49 The classes of elements are not abruptly separated, he stated, but shade "into each other in their characters, like the classes created by the naturalists for the objects of the organic world. "50... 

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Richard Grossman is a psychotherapist currently on staff at both the Albert Einstein College of Medicine and the Beth Israel Medical Center in New York. He has been director of the Center for Health and Medicine at Montefiore Hospital and Medical Center in New York and has written many books, including The Other Medicines (1985), The Natural Family Doctor (1987), and Fear at Work (1990). This 1983 article first appeared in Health magazine as part of Grossman s column called Richard s Almanac. ... 

Khoka, Cuca, Coca, or Spadie, the latter a corruption of the Brazilian word Ypadii or Ipadii, is of the natural family Erythroxylaceae, formerly Linaceae. It belongs to the genus Erythroxylum P. Br. which contains numerous species, the majority natives of tropical South America and the West Indies, although some are found in Madagascar and the Mauritius. 

Many chemists (and M. Dumas in particular), on several occasions, pointed out the existence of some interesting relations between the equivalents of the bodies which belong to the same natural family or group. 

While the elements will follow the nine vertical rows (to the first until the last depending by their molecular weight), the horizontal rows include the natural families. In order to obtain this arrangement, certain elements (of which atomic weight was found almost equal and which probably was not very carefully determined) have to be rearranged tellurium before iodine, osmium before iridium and platinum, and these before the gold. 

For numerical integration, the system (8.68)-(8.70) can be handled via splitting. A natural family of methods based on Verlet is the following [19] ... 

Yet Adanson said no such thing. He never explained exactly what use he made of his 65 artificial systems while seeking his natural families. The closest he came were these two statements ... 

If we consider cations belonging to a natural family, thus the series Ba, Ca, Mg or the scries Pb, Cu, Cd, then we find that indeed with a higher reversal of charge... 

Don, D. (1823). An illustration of the natural family of plants called Melastomataceae. 

We must conclude that apart from the ancient natural families of elements which have been recognized since long, we have got but artificial assemblies. The system of periodic series, just as the system of the multiples of hydrogen, so far did not provide any certain and definite rule for discovering either the simple substances recently discovered, or those that we do not know yet. ... 

Figure 5.2 In 1888 Leduc kept grouping metalloids in Dumas s four natural families and metals in Ihenard s six artificial sections (Leduc, Anatole, Cours eUmentaire de chimie redigi conformiment au programme de 1885 pour la classe de rhitorique et le haccalaureat es lettres (2e edition), Vve E. Belin et fils, Paris, 1888, p. 9).

The interest aroused by Mendeleev s periodic classification was also limited by its similarities with the main groups of elements, which have been established during the first half of the nineteenth century. The natural families of metalloids were widely used in textbooks, without any great controversy regarding their... 

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