The vote upon the charges and specifications must be taken by yeas and nays, beginning with the first specification under the first charge and continuing until all the specifications under the first charge have been disposed of. A vote must be taken in the same way upon each specification and all specifications and other charges in the articles of impeachment until they all are disposed of. If two-thirds of the members elected concur in favor of a conviction upon any of the charges or specifications the accused must be convicted, otherwise the accused must be acquitted.