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Discussion Groups / English Usage / January 2009litmus test
What does it mean "a litmus test". The entire sentence as below: And in some ways, they are a litmus test; a measure of the lake's health. Thanks in advance. > What does it mean "a litmus test". > > The entire sentence as below: > And in some ways, they are a litmus test; a measure of the lake's > health. When I studied chemistry in school, we used litmus paper to test the acidity of liquids. You got different colours depending on the pH value. >> What does it mean "a litmus test". >> [quoted text clipped - 4 lines] >When I studied chemistry in school, we used litmus paper to test the >acidity of liquids. You got different colours depending on the pH value. Yes, and now the meaning has been extended so that it can be figuratively used to refer to any "decisively indicative test" (COD). That works all right in examples like "the by-election will be a litmus test of the government's popularity" but it's rather unfortunate when it's used here as "a measure of the lake's health", in a situation where one can expect a real litmus test. One should also avoid describing Jerusalem as a Mecca for tourists. James > On Sun, 25 Jan 2009 11:48:11 GMT, Lars Enderin > [quoted text clipped - 15 lines] > lake's health", in a situation where one can expect a real > litmus test. But we don't have enough context; perhaps "they" are really, hm I meant figuratively, a "litmus test; a measure of the lake's health". > One should also avoid describing Jerusalem as a Mecca for > tourists. ...or Mecca "the Holy Land" In message <8f4ee0d4-3674-4d1f-af9c-fd8233c71d81@x14g2000yqk.googlegroups.com>, Arcadian Rises <Arcadianrises@aol.com> writes >On Jan 25, 7:070 >> On Sun, 25 Jan 2009 11:48:11 GMT, Lars Enderin >> [quoted text clipped - 23 lines] > >...or Mecca "the Holy Land" Or starting a crusade to allow non-muslims to be allowed to visit Mecca.  SignatureIan >> On Sun, 25 Jan 2009 11:48:11 GMT, Lars Enderin >> [quoted text clipped - 18 lines] >But we don't have enough context; perhaps "they" are really, hm I >meant figuratively, a "litmus test; a measure of the lake's health". On a body of water I would expect a litmus test to be only for acidity/alkalinity. Of course, they have better tests than litmus for that. Signature************* DAVE HATUNEN (hatunen@cox.net) ************* * Tucson Arizona, out where the cacti grow * * My typos & mispellings are intentional copyright traps * James Hogg filted: >One should also avoid describing Jerusalem as a Mecca for >tourists. I once heard a cow orker suggest that he needed to have "a little pow-wow with Anirudh" about some project plan...I asked him if he really meant to suggest a pow-wow with an Indian.... (They don't ork cows in Bangalore)....r Signature"You got Schadenfreude on my Weltanschauung!" "You got Weltanschauung in my Schadenfreude!" \ > One should also avoid describing Jerusalem as a Mecca for > tourists. I don't know about that. It sounds like the basis for a good ad campaign. John Kane Kingston ON Canada > > What does it mean "a litmus test". > > [quoted text clipped - 4 lines] > When I studied chemistry in school, we used litmus paper to test the > acidity of liquids. You got different colours depending on the pH value. As I recall, litmus paper turns either pink or blue to indicate acid or base (I forget which is which), but it does not give any but the roughest indication of the amount of acidity or alkilinity. It's either acid or base, but litmus doesn't tell how much. Thus the expression "litmus test" means a pass/fail criterion. A common example is abortion as a litmus test for a judicial nominee: the wingnuts on either side of the question will vote for or against the candidate on this criterion alone. SignatureJohn Varela Trade OLD lamps for NEW for email >As I recall, litmus paper turns either pink or blue to indicate acid >or base (I forget which is which), but it does not give any but the >roughest indication of the amount of acidity or alkilinity. It's >either acid or base, but litmus doesn't tell how much. And either would indicate that a lake was unhealthy. SignatureSteve Hayes from Tshwane, South Africa Web: http://hayesfam.bravehost.com/stevesig.htm Blog: http://methodius.blogspot.com E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk > >As I recall, litmus paper turns either pink or blue to indicate acid > >or base (I forget which is which), but it does not give any but the > >roughest indication of the amount of acidity or alkilinity. It's > >either acid or base, but litmus doesn't tell how much. > > And either would indicate that a lake was unhealthy. I was going to say the same thing, but http://en.wikipedia.org/wiki/Litmus_paper implies that litmus at full color, either red or blue, represents a pH either less than 4.5 or greater than 8.3. I don't know if that would indicate an unhealthy lake (again, yes or no) but it wouldn't surprise me to learn that it does. SignatureJohn Varela Trade OLD lamps for NEW for email >On Mon, 26 Jan 2009 23:50:09 UTC, Steve Hayes ><hayesmstw@hotmail.com> wrote: [quoted text clipped - 12 lines] >unhealthy lake (again, yes or no) but it wouldn't surprise me to >learn that it does. Well now, a pH of 7.0 is neutral. It's a logarithmic scale representing the negative of the logarithm to base 10 of the concentration (more strictly, the activity) in water of the H+ ion, which represents the acid principle. The other ion is OH-, representing the opposite or alkaline principle. The + and - represent electrical charge. Actually it's more complicated, but that will do. Most of water (H+ and OH- together make 2 H's and an O, or H2O) is plain un-ionised H2O. A body of water has a small proportion of its molecules separated into H+ and OH- ions, and is normally neutral, that is to say neither acid nor alkaline, the two ions being in balance and the pH being 7.0, meaning that the concentration of H+ is the number of grams ( strictly, mols) per litre whose log is -7: that is, 0.0000001 g/l. Because of the logarithmic nature of the scale, a pH of 6.0 has ten times as much acid principle, a pH of 5.0 represents 100 times as much, and 4.3 means (I haven't got my log tables out but maybe 200 times as much). A pH of 8.3 represents a deficiency of H+, made up for by an excess of OH-, the alkaline principle. The way the sums work is that if one is deficient, the other is in excess to the same degree. The sum of the exponents of the H+ and OH- concentrations in mols is always about -14. I think that's pretty clear. If I've remembered it aright, I'm impressed. So... on the numbers given, the lake would be spectacularly acid to turn litmus red, and only quite moderately alkaline to turn it blue. I imagine that lakes with naturally high soda concentrations could easily be that alkaline, so not unhealthy in an 'unnatural' sense. SignaturePaul >and 4.3 means (I haven't got my log tables out but maybe 200 times as >much). Engineering rules of thumb: 2:1 === +3 dB. +5 dB === 3.16:1. (In other words, sqrt(10) ~= 3.16, and log(2) ~= .3.) -GAWollman SignatureGarrett A. Wollman | The real tragedy of human existence is not that we are wollman@csail.mit.edu| nasty by nature, but that a cruel structural asymmetry Opinions not those | grants to rare events of meanness such power to shape of MIT or CSAIL. | our history. - S.J. Gould, Ten Thousand Acts of Kindness >In article <$0iZR6CMu5fJFADi@fpwolff.demon.co.uk>, >>and 4.3 means (I haven't got my log tables out but maybe 200 times as >>much). > >Engineering rules of thumb: 2:1 === +3 dB. +5 dB === 3.16:1. >(In other words, sqrt(10) ~= 3.16, and log(2) ~= .3.) My voices did speak to me and whisper that log 2 is 0.3010 and log 3 is 0.4771, but could I trust them? SignaturePaul >> >As I recall, litmus paper turns either pink or blue to indicate acid >> >or base (I forget which is which), but it does not give any but the [quoted text clipped - 9 lines] >unhealthy lake (again, yes or no) but it wouldn't surprise me to >learn that it does. Synecdoche? It would almost certainly be unhealthy for aquatic life, and most probably for lacustrine life that tried to drink from it as well. SignatureSteve Hayes from Tshwane, South Africa Web: http://hayesfam.bravehost.com/stevesig.htm Blog: http://methodius.blogspot.com E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk >What does it mean "a litmus test". > >The entire sentence as below: >And in some ways, they are a litmus test; a measure of the lake's >health. It measures the lake's pH. SignatureSteve Hayes from Tshwane, South Africa Web: http://hayesfam.bravehost.com/stevesig.htm Blog: http://methodius.blogspot.com E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk > It measures the lake's pH. No, litmus is far too crude to do that, litmus is either blue (alkaline) or red (acid) it is (if you like) digital to Universal Indicator's analogue. Litmus may indicate the pH but not measure it. Steve Hayes: > > It measures the lake's pH. Derek Turner: > No, litmus is far too crude to do that... Doesn't matter, the usage is obviously metaphorical anyway. They're just talking about a way to say "This lake is healthy" or "This lake is not healthy". Or rather, a way to say "This lake is not healthy" -- because if it was "healthy" in the first place, they would have been wasting their time, our attention, and someone's money. SignatureMark Brader, Toronto | Polly-ticks: Bloodsucking parasites that squawk msb@vex.net | mindless slogans in place of thought. --Chris Vernell My text in this article is in the public domain. >> It measures the lake's pH. > >No, litmus is far too crude to do that, litmus is either blue (alkaline) >or red (acid) it is (if you like) digital to Universal Indicator's >analogue. Litmus may indicate the pH but not measure it. Well, OK, but whether it's pink or blue, there's probably a problem with the health of the lake and whatever lives in it, apart from some "soda lakes" and the like. SignatureSteve Hayes from Tshwane, South Africa Web: http://hayesfam.bravehost.com/stevesig.htm Blog: http://methodius.blogspot.com E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk >>> It measures the lake's pH. >> [quoted text clipped - 5 lines] > the health of the lake and whatever lives in it, apart from some "soda > lakes" and the like. That's my point: it has to be either pink or blue before you start, there's no in-between! It'll be either pink or blue when you put it in. If it's neutral pink will stay pink and blue will stay blue. Litmus is all about whether it's acid/alkaline /enough/ to change the colour. It's very crude and either/or. [...] >> Well, OK, but whether it's pink or blue, there's probably a problem with >> the health of the lake and whatever lives in it, apart from some "soda >> lakes" and the like. > > That's my point: it has to be either pink or blue before you start, > there's no in-between! OYTI! Neutral litmus paper is purple and turns red or blue depending on the pH of the water it's dipped into, e.g.: <http://www.fishersci.com/wps/portal/!ut/p/c1/04_SB8K8xLLM9MSSzPy8xBz9CP0os\\ 3iTQCdLP3MPIwN_U39TAyMvP39DZyNvQ38LM6B8pFm8n79RqJuJp6GhhZmroYGRmYeJk0-Yp4G7\\ izEB3cGpefrhIDvxmwGSN8ABHA30_Tzyc1P1C3IjKjx1HRUB-i8U3Q!!/dl2/d1/L0lDU0lKSWd\\ rbUNTUS9JUFJBQUlpQ2dBek15cXpHWUEhIS9ZQkpKMU5BMU5JNTAtNUY4OXchIS83XzRRQjlON0\\ gyMDBSMkUwMkZUVk5HUEczMFYyL1BfX19fNS9zYS5Qb3J0bGV0TkFWQWN0aW9u/?ru=http%3A%\\ 2F%2Fprodwcsserver%3A9060%2Fwebapp%2Fwcs%2Fstores%2Fservlet%2FFisherProduct\\ Display&catalogId=29101&productId=701748&langId=-1&distype=2&isChemical=fal\\ se&fromCat=yes&catCode=SE_SC&brCategoryId=58477&hlpi=&highlightProductsItem\\ sFlag=&fromSearch=> <http://tinyurl.com/cebjq6> > It'll be either pink or blue when you put it in. > If it's neutral pink will stay pink and blue will stay blue. Litmus is > all about whether it's acid/alkaline /enough/ to change the colour. It's > very crude and either/or. SignatureLes (BrE) >>> It measures the lake's pH. >> [quoted text clipped - 5 lines] > health of the lake and whatever lives in it, apart from some "soda lakes" and > the like. I agree with Mark: it's clearly not supposed to be read literally. My guess is that the writer is just using litmus as a journalistic word and has no idea what it actually means. In any case, does anyone (outside of very elementary chemistry classes) still use litmus paper? Signatureathel > >>> It measures the lake's pH. > [quoted text clipped - 10 lines] > and has no idea what it actually means. In any case, does anyone > (outside of very elementary chemistry classes) still use litmus paper? Synonymous (?) with "acid test". Mike M >> >>> It measures the lake's pH. >> [quoted text clipped - 12 lines] > >Synonymous (?) with "acid test". Not chemico-etymologically. OED: acid test, the testing for gold by means of nitric acid; fig. a crucial test. SignaturePeter Duncanson, UK (in alt.usage.english) Mike wrote on Wed, 28 Jan 2009 08:30:20 -0800 (PST): > >>>> It measures the lake's pH. >> [quoted text clipped - 14 lines] >> > Synonymous (?) with "acid test". Essentially, I would say tho' "acid test" could also refer to a quick test for gold that, unlike many metals, will not dissolve in most acids. There are numbers of different testing strips used in chemistry including ones that have more than two colors to indicate degrees of acidity and others to detect specific chemicals. SignatureJames Silverton Potomac, Maryland Email, with obvious alterations: not.jim.silverton.at.verizon.not On Jan 28, 11:57�am, "James Silverton" <not.jim.silver...@verizon.net> wrote: > �Mike �wrote �on Wed, 28 Jan 2009 08:30:20 -0800 (PST): > [quoted text clipped - 31 lines] > > - Show quoted text - So what is the figurative difference, if any, between "acid test" and litmus test"? MW online: litmus [fig] : a test in which a single factor (as an attitude, event, or fact) is decisive OED: (quoted above by Peter Duncanson (BrE)) acid test, the testing for gold by means of nitric acid; fig. a crucial test. ================ IMO "acid" is somehow more powerful than "litmus", figuratively, of course. > On Jan 28, 11:57 am, "James Silverton" <not.jim.silver...@verizon.net> > wrote: [quoted text clipped - 53 lines] > IMO "acid" is somehow more powerful than "litmus", figuratively, of > course. IMO it's not about "powerful" but about value judgements. An acid test serves as a passing or failing measure. A litmus test sorts things out into two different sides, and can (though not must) happen without a connotation of one side being "passing" and the other "failing". An independent pollster (with no rooting interest in either party) might have a litmus test to help determine if someone's a Democrat or a Republican. They wouldn't have an acid test for that. But a die- hard partisan might have an acid test to see if you're really part of their party. But the connotation is that the acid test can be passed or failed. A litmus test might merely be categorizing things rather than judging them. >> On Jan 28, 11:57 am, "James Silverton" <not.jim.silver...@verizon.net> >> wrote: [quoted text clipped - 69 lines] >litmus test might merely be categorizing things rather than judging >them. That is certainly logical, but I'm not sure that every user of the phrases will use them with such care. SignaturePeter Duncanson, UK (in alt.usage.english) On Jan 28, 4:51 pm, "Peter Duncanson (BrE)" <m...@peterduncanson.net> wrote: > On Wed, 28 Jan 2009 13:40:20 -0800 (PST), "sjdevn...@yahoo.com" > >IMO it's not about "powerful" but about value judgements. An acid [quoted text clipped - 15 lines] > That is certainly logical, but I'm not sure that every user of the phrases > will use them with such care. I agree Also, while I was careful with my wording I didn't explicitly say that this is a bit of a one-way street in the uses I've heard: people tend to use "litmus test" both ways, but it's unusual to hear "acid test" in the sense of differentiating 2 equally decent outcomes. In hindsight I ought to have made that more clear. It might be a useful connotation for a non-native speaker to consider, but it's certainly not a bright-line rule. On Jan 28, 8:10�pm, "sjdevn...@yahoo.com" <sjdevn...@yahoo.com> wrote: > On Jan 28, 4:51�pm, "Peter Duncanson (BrE)" <m...@peterduncanson.net> > wrote: [quoted text clipped - 31 lines] > > - Show quoted text - You answered my question and I thank you very much. As for the logics and accuracy, which are not always favored by usage, as a student of language, I prefer to "err" on the side of too much correctitude and precision. Again, thanks for an enlightening answer. >>> It measures the lake's pH. >> [quoted text clipped - 5 lines] >health of the lake and whatever lives in it, apart from some "soda lakes" and >the like. A lake is not unhealthy simply because it is a little bit acid or a little bit alkaline. Signature************* DAVE HATUNEN (hatunen@cox.net) ************* * Tucson Arizona, out where the cacti grow * * My typos & mispellings are intentional copyright traps * >>>> It measures the lake's pH. >>> [quoted text clipped - 8 lines] >A lake is not unhealthy simply because it is a little bit acid or >a little bit alkaline. As I understand it, a litmus test doesn't show whether it is a little bit acid or a little bit alkaline. As others have pointed out, it's a fairly crude measure, and shows that it is rather more than a little. SignatureSteve Hayes from Tshwane, South Africa Web: http://hayesfam.bravehost.com/stevesig.htm Blog: http://methodius.blogspot.com E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk > [ ... ] > As I understand it, a litmus test doesn't show whether it is a little bit acid > or a little bit alkaline. As others have pointed out, it's a fairly crude > measure, and shows that it is rather more than a little. As far as I remember[1] litmus has a pK close to 7: in other words it will indeed show if the water is a little bit acid or a little bit alkaline. [1]The Merck Index tells me that I remember right, and that litmus is red at or below 4.5 and blue at or above 8.3, so it has a pK of about 6.4. I would call 4.5 a little bit acid, and 8.3 is certainly a little bit alkaline. In any case the Merck Index is being very conservative, and I would put the detectable range narrower than what they say, i.e. by red they mean completely red, and similarly for blue. Signatureathel >> [ ... ] > [quoted text clipped - 12 lines] >and I would put the detectable range narrower than what they say, i.e. >by red they mean completely red, and similarly for blue. Well, I'm sure the original poster has got plenty of material to choose from! SignatureSteve Hayes from Tshwane, South Africa Web: http://hayesfam.bravehost.com/stevesig.htm Blog: http://methodius.blogspot.com E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk >>> [ ... ] >> [quoted text clipped - 17 lines] > Well, I'm sure the original poster has got plenty of material to > choose from! Why don't hydrangeas understand all this? SignatureMike. Mike wrote on Wed, 28 Jan 2009 16:34:30 -0000: >>>> [ ... ] >>> [quoted text clipped - 17 lines] >> Well, I'm sure the original poster has got plenty of material >> to choose from! > Why don't hydrangeas understand all this? Hydrangeas respond to the availabilty of aluminum in the dirt. This differs between acidic and alkaline soils but is not quite the same thing as litmus. SignatureJames Silverton Potomac, Maryland Email, with obvious alterations: not.jim.silverton.at.verizon.not >> Well, I'm sure the original poster has got plenty of material to >> choose from! > >Why don't hydrangeas understand all this? Instinct. SignatureSteve Hayes from Tshwane, South Africa Web: http://hayesfam.bravehost.com/stevesig.htm Blog: http://methodius.blogspot.com E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk [ ... ] > Why don't hydrangeas understand all this? Maybe this is the moment to expose myself to universal ridicule from the more horticultural people that until corrected by a 3-year granddaughter a couple of years ago I thought that the oleanders that grow abundantly around here were rhododendrons (even though I knew perfectly well that rhododendrons don't like alkaline soil and that all the soil around here is strongly alkaline). Incidentally, do pedants say "rhododendra", or does even pedantry have its limits? Signatureathel Athel Cornish-Bowden wrote, in <6ude6gFek3shU1@mid.individual.net> on Thu, 29 Jan 2009 11:20:00 +0100: > Incidentally, do pedants say "rhododendra", or does even pedantry have > its limits? Being based on Greek it wouldn't have an "a" plural, your true pedant would more likely say "rhododendroi". SignatureNick Spalding BrE/IrE >Athel Cornish-Bowden wrote, in <6ude6gFek3shU1@mid.individual.net> > on Thu, 29 Jan 2009 11:20:00 +0100: [quoted text clipped - 4 lines] >Being based on Greek it wouldn't have an "a" plural, your true pedant >would more likely say "rhododendroi". On what criterioi do you base that statement? The OED gives "rhododendra" as an alternative plural, but there is no quotation with that form since Thackeray in 1843. James (BrE) James Hogg wrote, in <tq33o49lcb9jf17mnt82errialt1p29hgv@4ax.com> on Thu, 29 Jan 2009 11:16:37 +0000: > >Athel Cornish-Bowden wrote, in <6ude6gFek3shU1@mid.individual.net> > > on Thu, 29 Jan 2009 11:20:00 +0100: [quoted text clipped - 6 lines] > > On what criterioi do you base that statement? Simply a hazy memory of Greek plurals, expressed with tongue firmly in cheek. > The OED gives "rhododendra" as an alternative plural, but there > is no quotation with that form since Thackeray in 1843. > > James (BrE) SignatureNick Spalding BrE/IrE > Athel Cornish-Bowden wrote, in <6ude6gFek3shU1@mid.individual.net> > on Thu, 29 Jan 2009 11:20:00 +0100: [quoted text clipped - 4 lines] > Being based on Greek it wouldn't have an "a" plural, your true pedant > would more likely say "rhododendroi". No. That would be the plural if the singular were rhododendros, but rhododendron is neuter. Signatureathel >Maybe this is the moment to expose myself to universal ridicule from >the more horticultural people that until corrected by a 3-year >granddaughter a couple of years ago I thought that the oleanders that >grow abundantly around here were rhododendrons (even though I knew >perfectly well that rhododendrons don't like alkaline soil and that all >the soil around here is strongly alkaline). The first time I saw rhododendrons I thought they were oleanders. Are rhododendrons also poisonous? SignatureSteve Hayes from Tshwane, South Africa Web: http://hayesfam.bravehost.com/stevesig.htm Blog: http://methodius.blogspot.com E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk >> Maybe this is the moment to expose myself to universal ridicule from >> the more horticultural people that until corrected by a 3-year [quoted text clipped - 6 lines] > > Are rhododendrons also poisonous? I can't remember for sure, though I think they are. But what's interesting to know is that rhododendron /honey/ is poisonous. Horti-wise, don't prune them the way you'd prune oleanders, for heaven's sake. SignatureMike. >>> Maybe this is the moment to expose myself to universal ridicule from >>> the more horticultural people that until corrected by a 3-year [quoted text clipped - 8 lines] > > I can't remember for sure, though I think they are. Some varieties are. Others are not. Don't take any chances, though. > But what's > interesting to know is that rhododendron /honey/ is poisonous. Change that to "can be poisonous". It depends on the variety of the rhododendrons the bees processed. > Horti-wise, don't prune them the way you'd prune oleanders, for > heaven's sake. SignatureSkitt (AmE) Steve wrote on Thu, 29 Jan 2009 18:49:04 +0200: >> Maybe this is the moment to expose myself to universal >> ridicule from the more horticultural people that until [quoted text clipped - 3 lines] >> rhododendrons don't like alkaline soil and that all the soil >> around here is strongly alkaline). > The first time I saw rhododendrons I thought they were > oleanders. > Are rhododendrons also poisonous? I think they are. SignatureJames Silverton Potomac, Maryland Email, with obvious alterations: not.jim.silverton.at.verizon.not >>>>> It measures the lake's pH. >>>> [quoted text clipped - 12 lines] >or a little bit alkaline. As others have pointed out, it's a fairly crude >measure, and shows that it is rather more than a little. No, litmus measures can be a very accurate method for determining the pH, as I and others have explained. Litmus papers and fluids can be used to indicate a wide range of values, as well, so I wouldn't call them crude. SignatureRegards, Chuck Riggs Near Dublin, Ireland |
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