WEF Discussion Forums
Laboratory Management and Technical Issues
B. COLI ???
It's 1920, and your new copy of Standard Methods has just arrived....
What would you be doing when you determined "The Reaction" of your de-watered sludge? What would you determine using the "Sedgwick-Rafter" method?
And what would these be used for: USGS Platinum Rod-1902; English Standard Candle; Lovibond Tintometer?
And what tests would use these reagents: Pear's Precipitated Fuller's Earth; Lacmoid Indicator; Tolidin Solution; Silk Bolting Cloth; Liebig's Meat Extract?
Now, down to basics:
1) give the concentration of 1 grain/US gallon in more modern units
2) what was Clark's Scale used for?
3) what molar concentration is N/2 hydrochloric acid?
4) what in the world is B. COLI?
Most of this stuff I can't even begin to hazard a guess. I could google it but I feel that would be cheating. My only guesses are that the platinum rod is used in the preparation of color standards, the tintometer is used to read said standards, the meat extract is used as a broth or agar substrate for one of the microbiology methods, and N/2 HCl is 6 molar. How close am I?
This forum really needs to prompt you to log-in if posting as anonymous. The previous reply is me.
These are all guesses, google was not used.
Rounding off, I believe 1 grain/gallon would be about 17 mg/l. IIRC, there are 7000 grains to a lb, based on the weight of a "standard" barley corn.
The English Standard Candle was used for turbidity measurements.
Based on my homebrewing knowledge, I"m guessing the Lovibond tintometer was for some type of color determination.
Another guess from memory, Sedgwick-Rafter was a microscope slide marked off in gradations to help in counting colonies?
N/2 HCL would be a 0.5 normal solution of HCL.
So, Charles, are you going to provide the answers to this or not? I'm kind of anxious.
GSain goes to the head of the class.
For all of this and more, stay tuned for an upcoming edition of WEF's Laboratory Solutions where all will be revealed.
How about analyzing for lead, copper, and zinc in a water sample using a couple of chemicals, filter paper, a balance, a battery, and some Nessler tubes?
Ah, the good old days when chemists were CHEMISTS.
For those inquiring minds who have to know, I just discovered in the latest edition of Laboratory Equipment that the Lovibond Tintometer is still made. From the picture, it looks very high tech.
See for yourself at www.lovibond.com