Opening the text

The Elements of Bacteriological Technique: A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged.Eyre, J. W. H. (John William Henry)

Science

The Elements of Bacteriological Technique: A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged.

Name: The Elements of Bacteriological Technique: A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged.
Author: Eyre, J. W. H. (John William Henry)

Eyre, J. W. H. (John William Henry)

Bacteriology -- Technique

(a) Divide the figure representing the percentage strength of the
weakest lethal dilution of the carbolic acid control at the 2-1/2-minute
contact period by the figure representing the percentage strength of the
weakest lethal dilution of the x-disinfectant at the same period. The
quotient = phenol coefficient at 2-1/2 minutes.

(b) Similarly obtain the phenol coefficient at 30 minutes contact
period.

(c) Record the mean of the two coefficients obtained in (a) and (b) as
the _mean phenol coefficient_, or simply as the ~Phenol Coefficient~.

The details of the Final Test of an actual determination are set out in
the accompanying table.


TABLE 27

Organism employed, B. Coli Communis.

Culture Medium, Nutrient Agar (+10). Age, 24 hrs.
Temp. of Incubation, 37°C.

Quantities used { Culture  } Emulsion 0.1 c.c. + 5 c.c. Germicide.
                { Emulsion }

Room Temperature during Experiments, 17°C.

   Germicide   Strength          Time of exposure            Incubation
                       2-1/2   5  10  15  20  25  30  35    Time    Temp.
1 Germicide-x    4%      --   --  --  --  --  --  --  --   7 days.  37°C.
2 Germicide-x    3%      48   --  --  --  --  --  --  --   7 days.  37°C.
3 Germicide-x    2%      24   24  24  24  48  72           7 days.  37°C.
4 Germicide-x    1%      24   24  24  24  72  24  72       7 days.  37°C.
5 Germicide-x    0.5%    24   24  24  24  24  24  24  24  24 hours. 37°C.

1 Phenol         1.10%   --   --  --  --  --  --  --  --   7 days.  37°C.
2 Phenol         1.00%   24                                7 days.  37°C.
3 Phenol         0.75%   24   24  24  24  48               7 days.  37°C.
4 Phenol         0.70%   24   24  24  24  24  72           7 days.  37°C.
5 Phenol         0.65%   24   24  24  24  24  48  24  24   2 days.  37°C.


                    ((1.10/4.00) + (0.7/2.0))   0.27 + 0.35   .62
Phenol Coefficient = ------------------------ = ----------- = --- = 0.31
                                2                    2         2




APPENDIX.


METRIC AND IMPERIAL SYSTEMS OF WEIGHTS AND MEASURES.

The initial unit of the metric system is the Metre (_m._) or unit of
length, representing one-fourth-millionth part of the circumference of
the earth round the poles.

The unit of mass is the Gramme (_g._), and represents the weight of one
cubic centimetre of water at its maximum density (viz. 4° C. and 760 mm.
mercury pressure).

The unit of the measure of capacity is the Litre (_l._), and represents
the volume of a kilogramme of distilled water at its maximum density.

The decimal subdivisions of each of the units are designated by the
Latin prefixes _milli_ = 1/1000; _centi_ = 1/100; _deci_ = 1/10; the
multiples of each unit by the Greek prefixes _deka_ = 10; _hecto_ = 100;
_kilo_ = 1000; _myria_ = 10,000.

For a comparison of the values of some of the more frequently employed
expressions of the Metric System and the Imperial System, the following
may be found convenient for reference:

     ~Length:~

Public-domain text, read in full here on John Shaqi.

Opening the text

The Elements of Bacteriological Technique: A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged.Eyre, J. W. H. (John William Henry)

Science

The Elements of Bacteriological Technique: A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged.

Eyre, J. W. H. (John William Henry)

Bacteriology -- Technique

(a) Divide the figure representing the percentage strength of the
weakest lethal dilution of the carbolic acid control at the 2-1/2-minute
contact period by the figure representing the percentage strength of the
weakest lethal dilution of the x-disinfectant at the same period. The
quotient = phenol coefficient at 2-1/2 minutes.

(b) Similarly obtain the phenol coefficient at 30 minutes contact
period.

(c) Record the mean of the two coefficients obtained in (a) and (b) as
the _mean phenol coefficient_, or simply as the ~Phenol Coefficient~.

The details of the Final Test of an actual determination are set out in
the accompanying table.


TABLE 27

Organism employed, B. Coli Communis.

Culture Medium, Nutrient Agar (+10). Age, 24 hrs.
Temp. of Incubation, 37°C.

Quantities used { Culture  } Emulsion 0.1 c.c. + 5 c.c. Germicide.
                { Emulsion }

Room Temperature during Experiments, 17°C.

   Germicide   Strength          Time of exposure            Incubation
                       2-1/2   5  10  15  20  25  30  35    Time    Temp.
1 Germicide-x    4%      --   --  --  --  --  --  --  --   7 days.  37°C.
2 Germicide-x    3%      48   --  --  --  --  --  --  --   7 days.  37°C.
3 Germicide-x    2%      24   24  24  24  48  72           7 days.  37°C.
4 Germicide-x    1%      24   24  24  24  72  24  72       7 days.  37°C.
5 Germicide-x    0.5%    24   24  24  24  24  24  24  24  24 hours. 37°C.

1 Phenol         1.10%   --   --  --  --  --  --  --  --   7 days.  37°C.
2 Phenol         1.00%   24                                7 days.  37°C.
3 Phenol         0.75%   24   24  24  24  48               7 days.  37°C.
4 Phenol         0.70%   24   24  24  24  24  72           7 days.  37°C.
5 Phenol         0.65%   24   24  24  24  24  48  24  24   2 days.  37°C.


                    ((1.10/4.00) + (0.7/2.0))   0.27 + 0.35   .62
Phenol Coefficient = ------------------------ = ----------- = --- = 0.31
                                2                    2         2




APPENDIX.


METRIC AND IMPERIAL SYSTEMS OF WEIGHTS AND MEASURES.

The initial unit of the metric system is the Metre (_m._) or unit of
length, representing one-fourth-millionth part of the circumference of
the earth round the poles.

The unit of mass is the Gramme (_g._), and represents the weight of one
cubic centimetre of water at its maximum density (viz. 4° C. and 760 mm.
mercury pressure).

The unit of the measure of capacity is the Litre (_l._), and represents
the volume of a kilogramme of distilled water at its maximum density.

The decimal subdivisions of each of the units are designated by the
Latin prefixes _milli_ = 1/1000; _centi_ = 1/100; _deci_ = 1/10; the
multiples of each unit by the Greek prefixes _deka_ = 10; _hecto_ = 100;
_kilo_ = 1000; _myria_ = 10,000.

For a comparison of the values of some of the more frequently employed
expressions of the Metric System and the Imperial System, the following
may be found convenient for reference:

     ~Length:~

Public-domain text, read in full here on John Shaqi.

The Elements of Bacteriological Technique: A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged.

The Elements of Bacteriological Technique: A Laboratory Guide for Medical, Dental, and Technical Students. Second Edition Rewritten and Enlarged.

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