论文部分内容阅读
地球上的生物中间,有许多是肉眼所不能看见的有机体,牠们自成为一个世界。直到显微镜发明以後,人们才有可能研究他们所一向不知道的各种微生物,其中也包括着细菌,把这些有机体继续研究後,知道牠们中间有些是人类的朋友,帮助着发面包,制乳酪,酿麦酒,各种葡萄酒和酒精,给土壤施氮肥等等。可是大部分的细菌是有害的,牠们使人和动植物患各式各样的疾病。科学家在研究这些疾病的时候,逐渐认为这些疾病中,有些并不是细菌引起的,而是由一些尚未知的,小得连在最进步的显微镜中都无法看见的生物所引起的。直到上世纪的末叶,俄国科学家Д.И.伊凡诺夫斯基才把这些生物发现了。
Many living creatures on Earth are organisms that can not be seen by the naked eye, and they have become one world by themselves. It was not until the discovery of the microscope that it was possible for people to study the kinds of microbes that they had never known before, including bacteria, to continue their study of these organisms, knowing that some of them were human friends, helping to make bread, cheese, Ale, all kinds of wine and alcohol, nitrogen fertilizer to the soil and more. But most of the bacteria are harmful, they cause a wide range of diseases to people, animals and plants. As they studied these diseases, scientists gradually came to think that some of these diseases were not caused by bacteria but by unknown organisms that were so small that they could not be seen in the most advanced microscopes. Until the end of the last century, the Russian scientist Ivanovski discovered these creatures.