Wikipedia:Reference desk/Archives/Miscellaneous/2016 April 14

= April 14 =

Spitfires with pre-drilled holes
Reading this article I stumbled across the following nugget: "One of the lesser known stories of World War II is how Lord Nuffield (of Morris cars fame) nearly lost us the war by trying to build Spitfire planes like cars. Amongst other problems, he tried to build the planes with the holes for the rivets pre-drilled into the assembly parts, only for them to not line up when the plane was assembled." I have googled but come up blank. Can anyone find more information on how this came about, and the effect it had on Spitfire production? - Cucumber Mike (talk) 08:28, 14 April 2016 (UTC)


 * More information at Castle Bromwich Assembly.--Shantavira|feed me 09:05, 14 April 2016 (UTC)

How to save a dog
I recently saw a feelgood news story (here is the news story Heartbreaking-moment-severely-dehydrated-abandoned-dog-collapses-cries-finally-come-save-her) about a woman who saved a dehydrated dog by giving it some water. I wondered what I could do if I was in that situation but had no water available. Would imagining something really salty and then repetitively spitting into the dogs mouth produce enough liquid to save it? Or spitting into a cup enough to fill the cup and then giving it to the dog to drink (assuming you even had a cup, which you might not, which is why I suggested spitting directly into the dogs mouth). Also you can replace dog with any small animal or even a person, the question basically boils down to is spit a good enough substitute for water to save a dehydrated animal, and can an average person produce enough of it for this to work. 80.251.230.94 (talk) 19:32, 14 April 2016 (UTC)
 * If you were in a similar situation but didn't have water then you could simply go and get some water, and then return and give it to the dog. Its not likely that it would die while you were getting water (dying from thirst is a slow and painful process). And if you are too lazy to get water then you can use your own blood; if you don't cut a major artery you can probably survive bleeding for a while. The Quixotic Potato (talk) 20:46, 14 April 2016 (UTC)


 * A good practical down-to-earth answer.--Aspro (talk) 20:58, 14 April 2016 (UTC)
 * Well, of course "go get some water" is the obvious answer if water is available. Question closed, then? But wait, the question specifically said "no water available". So can we assume that this situation is not taking place is a democratic western country where clean tap water is within 10 meters reach? Or forget the premise entirely and just have a go of answering the underlying question of whether spit could re-hydrate someone and whether one person could produce enough within a reasonable time to do so? 80.251.230.94 (talk) 21:20, 14 April 2016 (UTC)
 * If water (or any other drinkable liquid) is not available there, and you travelled there without bringing any, then you need to be rescued, not just the dog. Even in non-Western countries where the water may not be as clean as it is here the people still depend on this vital resource. The Quixotic Potato (talk) 21:35, 14 April 2016 (UTC)
 * Story checks out. InedibleHulk (talk) 14:05, 18 April 2016 (UTC)


 * Humans produce between 0.75 to 1.5 litres of saliva per day (mostly during the day). It's 99% water.  Several dog health sites quote the figure that a dog needs 1/2 to 1 ounce of water per pound of body weight per day.  Well, how dehydrated is your dog (how much of it's daily needs are you planning to supply here) and is this a 250lb Male English Mastiff or a 2lb Chihuahua puppy?
 * To get that all into nice metric units: you need between 0.03 to 0.06 liters per kilo of dog per day - and you have between 1 and 100 kg of dog depending on age, gender and breed. So anywhere from 0.03 of a liter per day to 6 liters per day is the range here.  If a human makes spit for an hour you get 0.06 to 0.13 liters - you aren't going to help the Mastiff one little bit - but you'd be able to provide enough to keep that chihuahua alive - no problems...but sadly, the Mastiff's a gonner.


 * The dog in the video looks to be maybe 10kg. So 0.3 to 0.6 liters per day is what it needs and 0.75 to 1.5 is what a human can produce.


 * But what we don't know - and can't easily calculate - is how much fluid the dog has to be provided with (and in how much time) to prevent it from dying. Clearly it doesn't need a whole day's worth of liquid in one hour (which is good - because anything bigger than a chihuahua ain't gonna get it) - but maybe if you can avoid it losing any more fluids by supplying it with one hour's worth every hour until help arrives - and for that, I think it's plausible with a 20lb dog.
 * SteveBaker (talk) 21:21, 14 April 2016 (UTC)
 * Thank you! This is exactly the kind of answer I was looking for. Thanks for taking the time to explain it. 80.251.230.94 (talk) 21:23, 14 April 2016 (UTC)


 * The problem with calculating the amount of spit you can produce is that you have to be taking in fluids yourself to produce it. If there is no water for the dog, there will be none for you either: your mouth is going to dry up very quickly in that situation. 81.132.106.10 (talk) 18:06, 15 April 2016 (UTC)


 * Quite! When you are spitting, you are losing fluid from your body and one of the first things the body does as it dehydrates is reduce saliva production. If you really want to know if it's possible, fetch a glass from your cupboard, sit on the sofa and spit into it until you physically can spit no more, and see how much you produce.--Ykraps (talk) 18:36, 15 April 2016 (UTC)
 * It would take quite a while for the average human to produce half a liter of spit. But the average healthy human can probably lose half a liter of blood without any real problems. If you donate blood they take about 400-500ml afaik. This is probably enough, even for a big dog. The Quixotic Potato (talk) 06:26, 16 April 2016 (UTC)
 * I'm not saying it would take a while, I'm saying it can't be done without taking in fluids. All credit to Stevebaker for doing some research and trying to arrive at an answer logically and mathematically but I think he's made some errors. Firstly, the figure given for saliva production seems to be for a fully hydrated person who is taking in liquid and keeping his mouth closed for much of the day and secondly 0.6l is what is required to keep the dog at it's current level. As we are "saving it's life", we can assume it's severely dehydrated and therefore that amount is nowhere near enough. Nor could you save it by, as you're suggesting, donating your blood. Blood donors give around 470ml and after they are expected to rest and take in fluids []. A blood loss of 600ml, which I've already argued is insufficient, is second degree haemorrhaging, after which your heatbeat will have increased and you will probably be feeling faint []. Is no-one going to suggest urine?--Ykraps (talk) 10:28, 16 April 2016 (UTC)
 * I said "the average human". Not drinking and keeping your mouth open for much of the day are not things the average human does afaik. I based the number of milliliters of blood drawn during a blood donation on a Wikipedia article, which is based on several sources. Rough translation: "In Belgium they draw 400 or 470ml blood, depending on the height and weight of the donor, with a maximum of four times a year. For blood plasma the maximum is 650ml. In the Netherlands they draw 500ml blood or 650ml blood plasma" ( In België wordt er 400 ml of 470 ml bloed afgenomen, afhankelijk van de lengte en het gewicht van de donor, maximaal vier keer per jaar. Voor bloedplasma is dat max. 650 ml. In Nederland wordt er 500 ml bloed of 650 ml plasma afgenomen). Since I live in the Netherlands the amount I picked was 500ml; I mentioned the upper and lower boundaries. I think you will agree that 470 is between 400 and 500. Yes, blood donors are expected to rest and take in fluids, but it is not very likely that they will die if they simply rest for a while without taking in fluids (afaik). You make the oldschool assumption that someone who has had too much of one thing needs a lot of the opposite thing; e.g. put people who are very cold next to a blazing fire and give dehydrated dogs lots of water. I've heard that its a bad idea to give people who haven't eaten in a long time a lot of food at once, and I am beginning to suspect that moderation is key. Remember, if the dog is a Chihuahua puppy it is still a dog. With 0,6 liters of whatever bodily fluids you want to use you can give it its own swimming pool. It may not be a bad idea to give it a smaller amount of bodily fluids first, then transport it to a location where water or any other more conventionally considered "drinkable" liquid is available, which cannot be far otherwise the human(s) would need to be rescued too. Or you ask someone to get (or bring) water or you get it yourself. The Quixotic Potato (talk) 22:36, 16 April 2016 (UTC)
 * Under normal circumstances, nearly all of the saliva you produce is recycled, except for small amounts that evaporate when you have your mouth open. Air changes dry the mouth quicker so if you breathe with your mouth open or talk a lot, you will need to produce a bit more, but you are not using it up as you are when you are spitting. It is very easy to see how much you can spit, as I have already said above. Please do try it. I am a blood donor and often ignore the advice I am given without feeling any ill affects but I am bigger than average and therefore, presumably, have more blood to spare. The collection of blood takes around 15 minutes through a punctured vein so you are going to have to cut yourself pretty deeply to get a similar flow rate and let yourself bleed for perhaps 20 minutes to produce 600ml which will, in all probability, be insufficient for the dog's needs and will almost certainly cause you some short term harm and possibly other more serious problems.--Ykraps (talk) 07:11, 17 April 2016 (UTC)
 * I do not understand why you claim that 600ml is, in all probability, insufficient for the dog's needs. The Quixotic Potato (talk) 16:38, 17 April 2016 (UTC)
 * Because, as I have already said, 0.6 litres is the amount required to maintain the dog's current hydration level and we are trying to save it's life by rehydrating it. If a cell is short of water it starts to die off. Maintaining that level means the cell is still short of water and will continue to die.--Ykraps (talk) 16:56, 17 April 2016 (UTC)
 * I do not understand why you claim that "0.6 litres is the amount required to maintain the dog's current hydration level". The Quixotic Potato (talk) 18:40, 17 April 2016 (UTC)
 * Because, to quote Stevebaker, "Several dog health sites quote the figure that a dog needs 1/2 to 1 ounce of water per pound of body weight per day......you need between 0.03 to 0.06 liters per kilo of dog per day ". This is the amount a dog needs not more than it needs. A one kilo dog needs 0.6 litres to maintain a healthy level of hydration. Giving a dog it's recommended daily intake will maintain it's level of hydration and if that level happens to be insufficient, it will remain insufficient.--Ykraps (talk) 19:36, 17 April 2016 (UTC)
 * Sorry, I'm not being very clear. Let me try again. 0.6l is insufficient because the dog is still losing water at it's normal rate. A dog needs to take in 0.6l because during the course of a normal day it loses 0.6l. As the dog urinates, sweats, eats etc., it loses water for which it compensates by cutting down on non-essential usage; reducing saliva and urine production, and diverting this water to more important areas. In other words the animal builds up a water debt which is repaid when the now thirsty dog, drinks. This is normal for all animals and is not, in medical terms, dehydration and certainly not life-threatening. Dehydration is when the dog has exceeded it's normal water debt because, perhaps, it has been left in a hot car or it has over-exerted itself. This means the dog has to take in more than it's normal 0.6l and this is known as first degree dehydration. We are dealing with a dying dog which must therefore be severely dehydrated and will require even more.--Ykraps (talk) 20:31, 17 April 2016 (UTC)
 * Just to clarify: You cannot simply pour 0.6l into the dog, it simply won't absorb it all and most will pass through. That is why rehydration is done intravenously and hence my comment about the dog still losing water.--Ykraps (talk) 06:21, 18 April 2016 (UTC)
 * Not sure if I should enter in to this weird discussion but did you mean a ten kilo dog rather than "A one kilo dog needs 0.6 litres"? Or alternatively a one kilo dog needs 0.06 litres? Because otherwise I don't see how your figures follow. Nil Einne (talk)
 * You are absolutely right, Stevebaker's calculations means a 1kg dog requires 60ml not 600ml. I took the 600ml from The Quixotic Potato's post. I do not, however, believe that a 1kg dog requires 1/10 of a 10kg dog's intake. 60ml seems a ridiculously small amount!--Ykraps (talk) 06:27, 18 April 2016 (UTC)
 * You wrote: "I took the 600ml from The Quixotic Potato's post."... Are you sure? The Quixotic Potato (talk) 14:36, 18 April 2016 (UTC)


 * Keep in mind, dogs don't sweat. At least no more than a ridiculously small amount on the paw pads and nose. They pant. Constantly spitting in one's mouth will at least marginally disrupt this theromoregulation, and may pose a choking risk. InedibleHulk (talk) 14:18, 18 April 2016 (UTC)
 * Also you need to bear in mind that blood is not as efficient as water for hydration so consequently more will be required. If it is a hot day, the dog will also be in danger of overheating as the available water will have been diverted to the most important areas, such as the blood and internal organs.--Ykraps (talk) 17:49, 17 April 2016 (UTC)

I feel the need to strongly restate what others have mentioned or alluded to: rehydrating a dog by spitting into it is a terrible idea. If you find yourself faced with such a creature and spitting is the only recourse you can think of, I would humbly suggest you let the poor thing lay there quietly resting while someone competent goes for water. The stuff above about resuscitating it via your own blood takes a terrible idea and somehow makes it much worse. Matt Deres (talk) 13:19, 17 April 2016 (UTC)
 * Try reading between the lines. I wrote: "And if you are too lazy to get water then you can use your own blood". The Quixotic Potato (talk) 16:38, 17 April 2016 (UTC)
 * Try being helpful instead of coy. You're dealing with someone who is asking - apparently sincerely - whether they can re-hydrate a dog by spitting in it; giving them an even stupider idea to contemplate is unhelpful. The only answer this question needs is "Fuck no." Matt Deres (talk) 22:26, 17 April 2016 (UTC)
 * If you scroll up you'll notice that I gave some very helpful advice, see the first reply to the OP. OP wasn´t happy with the answer they got, and I explained why the question is silly. All other comments are unnecessary, including yours. The Quixotic Potato (talk) 14:31, 18 April 2016 (UTC)
 * The answer isn't "No it won't work" - because that depends entirely on the size of the dog - and whether you're just trying to keep it alive while real help arrives or not. For a small dog and a short period of time - I think it might actually work.  For the dog in the video - it's marginal at best - for a larger dog, it's definitely not going to work.  Are there better ways to handle a situation like this - yes, very probably - but it's not what we're being asked.   Our OP wants to know whether the story is bullshit, not whether it's something that should be attempted.  The answer to that is "It's borderline bullshit...right on the edge of being impossible...but not something we can dismiss on the basis of available evidence." 23.25.6.100 (talk) 12:47, 19 April 2016 (UTC)
 * You wrote: "Our OP wants to know whether the story is bullshit". The people in that story had water available. The Quixotic Potato (talk) 13:07, 19 April 2016 (UTC)