The micro-organisms of fermentation practically considered / by Alfred Jörgensen.

  • Jörgensen, Alfred, 1848-1925.
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: The micro-organisms of fermentation practically considered / by Alfred Jörgensen. Source: Wellcome Collection.

    48/198 (page 26)
    counting. Experinaeuts must also be made in order to determine of how many squares the eell contents must be counted in order to arrive at a true average. Such a counting and determination of the average number is con- tinued until tlie increased number of squares bas no influence on the average value. The number of countings necessary, and the accuracy generally, depend on the experience of the observer and the care exercised. Hansen found that under ordinary circumstances it was sufficient to count the cells in 48 or 64 small squares.