Now in both cases one gramme-molecule of oxygen is decomposed, and the two oxygen atoms thus formed are combined with two carbon valencies.
The volume of a gramme of water also depends on temperature and pressure.
System a subdivision of the latter, viz, the gramme, is adopted, and is associated with the centimetre as the unit of length, and the mean solar second as the unit of time.
Taking the centimetre, gramme and second as our fundamental units, the most convenient unit of force is that which, acting on a gramme for a second, produces in it a velocity of a centimetre per second; this is called a Dyne.
In the latitude of Paris the dyne is equal to the weight of about of a gramme, and the erg is the amount of work required to raise Ti lerof a gramme vertically through one centimetre.
To the gramme-equivalents or gramme-molecules of the reacting substances, or to some multiples of them.
Represents the heat of neutralization of one gramme-equivalent of caustic soda with nitric acid, each in dilute aqueous solution before being brought into contact.
If now it is required to find the heat of formation of the compound CO, which cannot be directly ascertained, we have merely to subtract the second equation from the first, each symbol representing constant intrinsic energy, and thus we obtain C+0 - 00= 26300 cal., or C+0=C0+26300 cal., that is, the heat of formation of a gramme-molecule of carbon monoxide is 26300 cal.
A continuous electric current of one ampere is defined to be one which deposits electrolytically 0.001118 of a gramme of silver per second from a neutral solution of silver nitrate.'
01 gramme of the substance to be estimated.
Kopp, begun in 1842, on the molecular volumes, the volume occupied by one gramme molecular weight of a substance, of liquids measured at their boiling-point under atmospheric pressure, brought to light a series of additive relations which, in the case of carbon compounds, render it possible to predict, in some measure, the cornposition of the substance.
The heat of combustion of one gramme-atom, is 96.96+4.
In the first case the thermal effect of 58.58 calories actually observed must be increased by 2d to allow for the heat absorbed in splitting off two gramme-atoms of carbon; in the second case the thermal effect of 96.96 must be increased by d as above.
Thomsen deduced that a single bond between a carbon and a nitrogen gramme-atom corresponds to a thermal effect of 2.77 calories, a double bond to 5.44, and a treble bond to 8.31.
The relation they suspected to be of the form -yS = KT, where K is a constant analogous to R, and S the surface containing one gramme-molecule, y and T being the surface tension and temperature respectively.
Perfectly pure distilled sea-water dissociates, to an infinitesimal degree, into hydrogen (H) and hydroxyl (HO) ions, so that one litre of such water contains 1 X 10 7, or 1 part of a gram-molecule of either hydr010,000,000 gen or hydroxyl (a gramme-molecule of hydrogen is 2 grammes, or of hydroxyl 17 grammes).
Now this ratio is the same as that which gives the relative chemical equivalents of hydrogen and copper, for r gramme of hydrogen and 31.8 grammes of copper unite chemically with the same weight of any acid radicle such as chlorine or the sulphuric group, SO 4.
The theoretical value for the depression of the freezing point of a dilute solution per gramme-equivalent of solute per litre is 1857° C. Completely ionized solutions of salts with two ions should give double this number or 3.714°, while electrolytes with three ions should have a value of 5.57°.
Loomis for the concentration of o oI gramme-molecule of salt to one thousand grammes of water.
The number of undissociated molecules is then I - a, so that if V be the volume of the solution containing I gramme-molecule of the dissolved substance, we get q= and p= (I - a)/V, hence x(I - a) V =yd/V2, and constant = k.
This is fully borne out by the experiments of Julius Thomsen, who found that the heat of neutralization of one gramme-molecule of a strong base by an equivalent quantity of a strong acid was nearly constant, and equal to 13,700 or 13,800 calories.
When one gramme of zinc is dissolved in dilute sulphuric acid, 1670 thermal units or calories are evolved.
Hence for the electrochemical unit of zinc or 0.003388 gramme, the thermal evolution is 5.66 calories.
Thus a strip of zinc plunged into a solution of silver sulphate, containing not more than 0.03 gramme of silver in the litre, becomes covered with a flocculent precipitate which is a true alloy of silver and zinc, and in the same way, when copper is precipitated from its sulphate by zinc, the alloy formed is brass.
The unit of mechanical force in the " centimetre, gramme, second " (C.G.S.) system of units is the dyne, which is approximately equal to 1/981 part of the weight of one gramme.
The monetary unit is the gold colon weighing 778 gramme, 900 fine, and thus worth about 23d.
-- 20, 10, 5, 2, 1 kilograms; 500 to 1 gramme; 5 to 1 decigram; 5 to 1 centigram; 5 to 1 milligram.
It is clear that the effect of this "plongeur," when placed in the lower pan, is exactly the same as that of the 5 gramme weight in the upper pan.
Thus number loo would be 100 metres per gramme calculated on the single strand.
This latter differs very little in actual practice from the previous method of determination by the number of deniers per 476 metres, the denier being calculated on the equivalent of 0.0531 gramme, the English equivalent showing 333 deniers per one dram avoirdupois.
Thus if in one gramme of a mixture of water, alcohol and salt we are told the amount of water and salt, we can tell the amount of alcohol.
The molybdate solution should be of such a strength that i cc. will precipitate o oi gramme of lead.
The ore (0 5 gramme) is digested with a mixture of potassium nitrate and nitric acid.
000013 gramme of water.
Thus a= 2.54 cros., or one inch very nearly.] Tables Of Surface-Tension In the following tables the units of length, mass and time are the centimetre, the gramme and the second, and the unit of force is that which if it acted on one gramme for one second would communicate to it a velocity of one centimetre per second: - Table of Surface-Tension at 20° C. (Quincke).
3 X 10 24 gramme and that the unit atomic charge or natural unit of electricity is 1.3 X 1020 of an electromagnetic C.G.S.
The mass of the electron or corpuscle is 7 0 X1028 gramme and its diameter is 3 X I 013 centimetre.
Gramme (1826-1901) inaugurated a departure from which we may date modern electrical engineering.
Gramme dynamos were then soon made on the self-exciting principle.
In 1873 at Vienna the fact was discovered that a dynamo machine of the Gramme type could also act as an electric motor and jwas set in rotation when a current was passed into it from another similar machine.
Meanwhile the early continuous current dynamos devised by Gramme, Siemens and others had been vastly improved in scientific principle and practical construction by the labours of Siemens, J.
Thus in twenty years from the invention of the Gramme dynamo, electrical engineering had developed from small beginnings into a vast industry.