Tuesday, March 17, 2020
Ira Remsen essays
Ira Remsen essays Ira Remsen was born on February 10, 1846 in New York city. Even though he was born in the United States, he was educated in Germany. He received his M.D. at Columbia University in 1867 and he also earned a Ph.D. at the University of Munich and Gttingen in Germany. After receiving his degrees, Remsen began his investigation in pure chemistry at the University of Tbingen. It was in Germany and in Europe Remsen did most of his research. In 1876 he returned to the United States where his became one of the original faculty of Johns Hopkins University. There he founded the chemistry department. He was an excellent professor who trained a generation of prominent chemists. He was also the Director of the Chemical Laboratory and secretary of the Academic Council. In 1879, he was the founding editor of American Chemical Journal. Also in that same year, he made a remarkable, accidental discovery with a fellow researcher Constantine Fahlberg when they were working on a derivative of coal tar. One night, after a long day in his laboratory He we was having dinner with wife. When he was eating a regular roll. Remsen noticed that it was quite sweet at first, but it left a bitter after-taste. He made his wife taste the bread and he found nothing wrong or something unusual about the taste. So Remsen decided to taste his fingers and there he found that same sweet then bitter taste despite washing his hands thoroughly after working in his lab. After dinner, he returned to his laboratory and started to taste all the chemicals he was handling. When he found that chemical, it was oxidation of o-toluenesulfonamide and he called it saccharin. In 1880, Remsen and Fahlberg published their findings in the February issue of The Chemical Journal. Many people thought that it was Constantine who discovered saccharin, but he stole the formula from Remsen. When they stopped working togethe ...
Sunday, March 1, 2020
How to Conjugate French Regular -IR Verbs
How to Conjugate French Regular '-IR' Verbs There are five main kinds of verbs in French: regular -er, -ir, -re, stem-changing, and irregular. Once youve learned the rules of conjugation for each of the first three kinds of verbs, you should have no problem conjugating regular verbs in each of those categories. Regular -ir verbs are the second-largest category of French verbs. Indeed, these verbs are often referred to as second conjugation verbs. The verb form that ends in -ir is called the infinitive, and -ir is the infinitive ending. (In English, by contrast, the infinitive is the verb preceded by the word to.) The French verb with the infinitive ending removed is called the stem or radical.à Conjugating Regular French -irà Verbs To conjugate regularà -irà French verbs, its best to run through an example, step by step. Conjugate the French wordà choisirà (to choose), for example, by following these steps: Remove the infinitive ending (-ir)à to find the stem (also called the radical).Note that the stem- the verb withoutà theà -ir ending- isà chois.Add the appropriate simple conjugation ending/s shown in the table in the next section. Note that the conjugation table below does not includeà theà compound tenses, which consist ofà a form of the auxiliary verbà andà the past participle.à Choisirà normally requires the auxiliary verbà avoirà (to have) inà compound tenses and moods. Forà example,à Jaià choisià wouldà transelateà as I have chosen. But, if you were to extend the sentence, you would delete theà present perfect, as in:à Jaià choisià deuxà là ©gumes verts. I picked (chose) two green vegetables.à Example Conjugations To conjugate an -ir verb in the present tense, remove the infinitive ending and then add the appropriate endings. For example, here are the present tense conjugations for the regular -ir verbsà choisir,à finirà (to finish), andà rà ©ussirà (to succeed): Pronoun Ending choisir chois- finir fin- russir russ- Je -is choisis finis russis Tu -is choisis finis russis Il -it choisit finit russit Nous -issons choisissons finissons russissons Vous -issez choisissez finissez russissez Ils -issent choisissent finissent russissent Some Common French Regular -ir Verbs French regular -ir verbs, the second largest group of French verbs, share aà conjugation pattern. Here are just a few of the most common regular - ir verbs: Abolirà à to abolishAgirà à to actAvertirà à to warnBà ¢tirà à to buildChoisirà à to chooseà ©tablirà à to establishà ©tourdirà à to stun, deafen, make dizzyFinirà à to finishGrossirà à to gain weight, get fatGuà ©rirà à to cure, heal, recoverMaigrirà à to lose weight, get thinNourrirà à to feed, nourishObà ©irà to obeyPunirà à to punishRà ©flà ©chirà à to reflect, thinkRemplirà à to fillRà ©ussirà à to succeedRougirà à to blush, turn redVieillirà à à to grow old Exceptions: Irregular -ir Verbs Most of the French -ir verbs are regular verbs, which conform to the previously discussed rules for conjugation. Its important to keep in mind that there are a number ofà irregular -ir verbsà in French. These verbs can be tricky, but there is some good news: Only about 50 irregular -ir verbs exist in French, and they have only 16 conjugations. To simplify things further, most of those fall into just three groups. The first group of irregularà -irà verbs is essentially conjugated like the verbà partirà (to leave).à Thisà group includes such verbs as: Consentirà to consentDà ©partirà à to accordDormirà to sleepà Endormirà à to put/send to sleep The second group consists of verbs that end inà s of these verbs include: Couvrirà à to coverà Cueillirà à to pickà à Dà ©couvrirà to discoverEntrouvrirà à to half-open In the third group, verbs such asà tenirà (to hold) andà venirà (to come) and their derivatives follow a shared conjugation pattern in the present tense. Note, however, a major difference in the compound tenses:à Venirà and most of its derivatives useà à ªtreà as theirà auxiliary verb, whileà tenirà and its derivatives useà avoir. Wild Cards The remaining irregularà -irà verbs dont follow a pattern.à You just have to memorize the conjugations for each of the following verbs separately. Luckily, they are among the most frequently used French verbs, so memorizing their conjugations is completely worth the trouble. They include: Acquà ©rirà toà acquireà à Asseoirà to sitAvoirà à to haveConquà ©rirà toà conquerCourirà à to run
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