Service of notice; form; sufficiency

The notice referred to may be served personally upon the employer, or upon any agent of the employer upon whom a summons may be served in a civil action, or by sending it through the mail to the employer at the last known residence or business place thereof within the state, and shall be substantially in the following form: "To (name of employer): You are hereby notified that a personal injury was received by (name of employee injured), who was in your employ at (place) while engaged as (nature of employment), on or about the ....... day of ................... , nineteen hundred and ........ , and that compensation will be claimed therefor. Signed, .................................................. ." No variation from this form shall be material if the notice is sufficient to advise the employer that a certain employee, by name, received an injury in the course of his employment on or about a specified time, at or near a certain place. Notice served at the office of, or on the person who was the employee's immediate superior, shall be a compliance with this article.