XIII. Translate the text in writing with a dictionary paying attention to infinitive constructions (you are given 30 min.)

a) The units of living matter cover a wide range of sizes. A few sorts of cells are large enough to be seen by the unaided eye; to be seen, they must be at least 0.1 milli­meters, or 100 microns, in one dimension. Many animal eggs, which are single cells, are this large. Among the few plant cells which are this large are the cells in the fleshy portion of the watermelon. Most cells are smaller than this and are said to be microscopic in size; that is, within, the range of an ordinary light microscope. Below this range is another into which fall the viruses. Particles of known viruses generally occupy the size range 100 to 1 000 or 10 to 100 millimicrons. Thus, viruses are in­dividually invisible in the light microscope and are said to be submicroscopic, although they can be visualized with the electron microscope. Within this same size range fall several aggregations of molecules which make up the structural components of many types of cells. Between the viruses which have not been demonstrated to have cellular organization, and the bacteria, which have been demonstrated to have a characteristic type of cellular organization, falls a group of organisms known as the Rickettsias. The Rickettsias are considered by some investigators to be cellular; by others to be noncellular and perhaps similar to the viruses.

b) The chemical analysis of plants is to show what the plant contains, what food it requires; the chemical analysis of the soil is to show what the latter lacks; a comparison of the results of the first analysis with those of the second will give an answer as to how soil fertility is to be raised. The result of this analysis cannot be considered comp­lete unless it is concluded by a summarized synthesis. Be­sides, both the physical and the chemical analysis of the soil are needed. But neither the one nor the other taken separately, nor both together, can solve the problem of soil fertility, still less the problem of the development of fertility, of the development .of soils. This evolution can be understood only if we study soil as a developing in­tegral whole governed by the activity of plant and animal organisms. We cannot imagine either the origin or the for­mation of soil without the direct participation of plants. Plant physiology is the principal basis of all the conclu­sions of agricultural science. If the soils of today are to be cleared of plants for a number of years it will rapidly lose its fertility and become barren dust.

TEXT 14.

Read and translate the following words:

plantation, disease, paralyze, cure, recorder, commercial, search, cause, receive, dangerous, hull, appreciate, spontaneously, neutralize, require, necessary, view, suggest, impression, scurvy.

FOOD FACTORS

In the Dutch East Indies in 1897 men on the plantations were falling sick with a strange nerve disease. They were unable to eat or hold their food. Their arms and legs became paralysed and shrunken. So many were sick, that the hospitals had no more room for victims of this disease, known as beriberi. The Dutch physician Dr. Christian Eijkman was sent from Holland to try to find out how to prevent and cure this disease. Eijkman was immersed in germ theory. He was sure that beriberi was a bacterial disease. He brought chickens with him and hoped to cultivate the germ in them. But in this he failed. However during the course of 1896 these chickens came down spontaneously with a disease very much like beriberi. Before Eijkman could do much about it, the disease vanished. Searching for causes, he found out that a certain period of time the chicken had been fed on polished rice from the hospital stores and it was after that they sickened. Put back on commercial chicken food, they recovered.

Dr. Eijkman also learnt that the favourite food of the people was white-polished rice. This was prepared by rubbing off the brown outer coating of the rice grains. Dr. Eijkman decided to try an experiment. He fed a number of hens with polished rice until they became paralysed. The hens were then divided into two groups. One group, the control, was kept on the usual polished diet. The other group was given not only polished rice, but the other brown rice skins as well. In a short time, the control group which ate nothing but white rice died of beriberi. The test group that received the brown rice polishings was cured.

This was the first carefully controlled experiment showing that there was something in a food that could prevent a dangerous disease. Eijkman did not appreciate the true meaning of this at first. He thought there was a toxin of some sort in rice grains and that this was neutralized by something in the hulls. The hulls were removed when rice was polished, leaving the toxin in the polished rice unneutralized.

However, why assume the presence of two different unknown substances, a toxin and an antoxin, when it was only necessary to assume one: some food factor required in trace? The outstanding exponents of this latter view were Hopkins and a Polish-born biochemist Casimir Funk. Each suggested that not only beriberi, but also such disease as scurvy, rickets were caused by the absence of trace of food factors.

Under the impression that these food factors belonged to the class of compounds known as "amines" Funk suggested these factors be named vitamins (the life amines) and ever since the name was adopted.

"Biology and Human Progress"

by L.Eisman, Ch.Tanzer.

Date: 2016-01-03; view: 2303