CAR
CAR
C 85 )
The carbonic acid gas was obtained from marbleand dilute sulphuric acid, and was of suchpurity that 99 parts out of 100 were absorbed bylime water.
A glass globe previously exhaused of air, wasfilled with 21 cubic inches of the carbonic acidgas in the state in which it was procured,which weighed 10.2 grains at 44°. therm, and29.86. bar.
These 21. cubic inches equalled 21,58 atmean pressure and temperature, and hence 100.cubic inches of carbonic acid gas weigh underthese circumstances 47.26 grains.
Oxygen gas was then obtained from oxymu-riat of potash over mercury, which when ana-lyzed by the nitrous sulphat of iron, left an un-absorbed residue of only 2 in 100. The glassglobe holding 21 cubic inches was filled withthis oxygen under the same pressure andtemperature, which weighed 7.3 grains. Hencethe weight of 100 cubic inches of oxygen of 98per cent, purity weigh at 60°. ther. and 30 n .bar. 33.82 grains.
The experimenters then ascertained by trialson known mixtures of carbonic acid gas andoxygen, that lime water would extract thewhole of the carbonic acid from such a mixture.
The experiments on the combustion of char-coal were then performed by passing oxygenfrom one gasometer to the other through theplatina tube containing the charcoal alreadyheated to redness. The results of each experi-ment were as follows r
1. Four grains of Box-wood charcoal wereall consumed except 0.02 grains of ash, andproduced 13.76 grains of carbonic acid, whichoccupied exactly the same volume as the oxygenof which it was composed. No flash of lightwas observed during the combustion, whencethe absence of hydrogen was inferred. The3.98 grains of pure charcoal took 9.85 grainsof oxygen for its combustion, which shouldtherefore have produced 13.83 grains of car-bonic acid. The actual quantity of carbonicacid obtained was 13.76 grains, making a dif-ference of only .07. It may be observed that onanalyzing the entire gas at the end of the expe-riment, after removing the carbonic acid gas bylime-water, and the oxygen by nitrous sulphatof iron, exactly the same proportion of unab-sorbed residue was left as the oxygen itself fur-nished before the experiment, whence it wasinferred by the experimenters (and with greatrobability) that no gas whatever was furnishedv the combustion of the charcoal except car-
bonic add. This residue however was not ae-tually analyzed, but was taken as azote.
Calculating from the quantity of oxygen andcharcoal actually consumed in this experiment 1 ,the carbonic acid should be 13.83 grains, whichwould give 28.77 grains of charcoal in 100grains of carbonic acid.
Calculating from the volume of carbonic acidactually produced, which was 29.13 cubicinches, its weight (from the data originallyfound) must be 13.76 grains, which containedthe 3.98 grains of charcoal consumed, and hence100 grains of carbonic acid must contain 28.92grains of charcoal.
2. The second experiment was on the com-bustion of transparent Brazilian diamond. Thiswas performed precisely in the same manner as.the last. The oxygen gas was repeatedly passedover the red-hot diamonds for ten minutes.The combustion did not raise the heat to white-ness as with charcoal, as it went on more slowly.The portions of diamond that remained uncon-sumed at the end of the experiment were all re-duced to an opake white substance resemblingenamel. There was no discolouration of theplatina vessel nor any ash whatever. Out of3.93 grains of diamonds employed, 2.49 grainswere consumed. The results will be givenpresently in a tabular form. No water what-ever was condensed in the gasometer after theexperiment.
3. A second experiment was made on 4.01grains of diamonds. In a quarter of an hourthey were totally consumed, and not a vestigeleft.
4. The next experiment was made on Welchstone-coal or culm, used by maltsters, whichcontains little or no maltha, and burns withoutflame. This was previously strongly heatedunder sand. The oxygen was passed over fourgrains of it in the platina tube for ten minutes,and the whole was consumed except half a grainof residue-
5. Plumbago was next tried. In a quarterof an hour 4 grains of it were consumed except.2 of a grain of oxyd of iron.
6. Muscular fibre distilled in a coated glassretort, left a black shining animal charcoal*4 grains of which were put into the platina tubeand heated. The first time the oxygen gaspassed over it, a lambent flame filled the wholeof the glass tube, connecting the platina tubewith the gasometer. After the experiment, aminute portion of charcoal remained, and aquantity of saline matter adhered to it so firmly,