Fires And Explosions - DBH1 The Web Site 2021

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Fires And Explosions

Ever since I can remember I wanted to be an experimental chemist. When I was very young I had a wallpaper which depicted chemists doing interesting things with retorts and bunsen burners and sparks flying. I spent many hours of my childhood illnesses looking at these pictures and I was convinced that was what I wanted to do.

The first experiment I can remember was collecting poppy heads in the garden and mashing them up with water, pushing them in a bottle and waiting for opium to come out at the far end. In fact all that came out after or so  was a black smelly mess.

I was about 11 when in the summer holidays my friend and I decided to make some beer, as you do. So we got a beer kit and did all the brewing bit, boiling it up and letting it ferment and the rest. Goodness knows how or why my friens parents let us. Eventually the process was concluded and we poured the beer into bottles ready to drink. The beer lay in his parent's garage whilst he went off on holiday, on his own to Ayr to stay with some relatives. A couple of days later his mother appeared and demanded that I sort the beer bottles out. They were exploding in the garage! I scooped them up and threw them one by one into the woods – where I have to say they did explode most satisfactorily.

From a fairly young age I had read somewher about the composition of gunpowder. It is three chemicals, you grind them together and you very rapidly have an explosive mixture. Amazingly you could go to the local chemist and say that you would like some sulphur, some saltpetre and some carbon and they would supply you. You could then go home grind the materials together and make bangers or simply throw a match at the mixture and watch it flash.

Bangers were fireworks that you could buy around fireworks night. I think there was meant to be some kind of age restriction on who could buy them but if there was it was completely ignored by everybody. The idea was that you’d like the banger and stand well back until it went pop. However, that was kind of tedious, so to begin with we’d throw them at each other and when that palled we'd stick one into the middle of an apple that we’de found and blow the apple up. And then when that palled we’d put it in the apple throw the apple into the pond and explode it underwater. The first time that one exploded in my hand I was kind of shocked but after that I became quite blase about it.

Of course I was fascinated with combustion process. I don’t know how I found out, but it turned out that if you pour methylated spirits onto your hand and light it you get a colourless flame which extinguishes before it burns you. I also experimented with petrol. It is perfectly true if you syphon off petrol from a car into a jam jar using a length of hose and then you throw a match at the petrol the petrol extinguishes the match. On the other hand if you do it the other way around and throw the petrol at the match you get a very satisfactory heat flash.

The word went round the school that the local Army and Navy surplus stores had suddenly gained a stock of calcium acetaldehyde. This is a chemical which gives off Acetylene if water is dripped onto it. So you could buy Acetylene lamps that gave light from burning Acetylene. In fact bicycle lamps were often in the dim and distant past powered by Acetylene, as were car headlights. It was far more fun though to take a lump of the chemical and drip water onto it and light it. However this palled after a while and we hit open the idea of putting the chemical with some water in a glass jar and throwing it. The explosion that resulted as the gas blew open the glass was most satisfactory. The woods which were behind the houses must have had a lot of glass blasted through them by my exploits.

One of the lads at school suggested that we might make some rockets. The intention was to cut the ends of matches and then stuff the match heads into a tube, attach a stick and seal one end of the tube. Hey presto, you have a rocket. Unfortunately you need a lot of match ends  in order to fill a small rocket. So we had happy afternoons where we go and buy as many boxes of matches as the local newsagent would sell us and then we'd spend the afternoon with knives chopping off the red tip of the match. Gradually a pile of the red chemical would appear in the middle of the table. Unfortunately on a few occasions the action of cutting the end off would cause the match to ignite and immediately the pile of red powder would flash burn. Surprisingly nobody ever complained about the holes that we left in the table. The rocket body would be aluminium tube which cigars came in.  We were for ever trying to persuade adults to smoke more to give us the tubes. The rockets when we eventually got to launch them, zoomed into the sky very satisfactorily about half the time and the other half just flashed.

I found an old chemistry textbook where it described how to make nitrous oxide which is also called laughing gas and was used for many years as an anaesthetic. From memory the process involved boiling a solution of ammonium nitrate. The gases were collected from the retort through water into a beehive jar. We tried this at my house and it was hilarious. Whether it was hilarious because of the gas or because we just thought it was funny I don’t know. After we had made several jars full of gas and sniffed them and fell about laughing there was an almighty explosion. It was a miracle we weren’t hurt. We turned back to the chemistry manual which said under no circumstances should the mixture be allowed to reduce to a small volume because it then becomes dangerously unstable and will explode. We’d rather proved that the hard way.

The school to which I went was the local grammar school there was a Physical and Chemical society which met once a week. Amazingly the idea was you could go into the lab and having got approval of the chemistry master you could carry out your own experiments. Needless to say all the experiments we wanted to carry out involved explosions or at the very least high rates of combustion. It seems incredible now that we could just light magnesium strips or therow sodium into water or even better toss potassium into water and watch the effects. Of course, we searched the old chemistry books and found out about nitrogen tri iodide. From memory all you do is to dissolve iodine in concentrated nitric acid and then allow the mixture to dry. Whilst moist the chemical is very stable but when dry it's very unstable. The classic experiment is to get a crystal of the chemical and get a fly to land on it somehow, at which point the fly blows itself to kingdom come. The amount that I made was small and sensible but of course other people wanted to carry they experiment to extremes. We were going on a weekend outing in the minibus when one of the lads announced that he’d made 100 grammes of nitrogen tri-iodide which had it exploded would have left at least a big hole in the minibus and possibly much worse. The kicker was that he'd lost it and we never did find it. Maybe it’s out there somewhere still wait to go off.

There were two physics sets in the sixth form I was in one and some guys that I knew were in the other one. I was wandering through the lab where they were carrying out some kind of experiment. I’ve no idea what it was but it involved quite a lot of benzene. Even in those days benzene was regarded as being some kind of an unpleasant chemical. One of the guys had spilt half a beaker of benzene on the bench. He knew he would get in trouble. I suggested to him that if he lit it, it would evaporate and no one would be any the wiser. So he did just that. The clouds of black acrid smoke that came billowing from that bench with sight to behold. They had to evacuate the entire science block. Somehow I never got blamed for it.

Looking back I’m amazed that no grown ups seem to have a problem with any of these exploits, in fact somehow I think they thought it was educational. I suppose to a certain extent it was. I was testing how far I could push the world before it came back and bit me.

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