787 



EFFERVESCENCE. 



EGYPTIAN ARCHITECTURE. 



768 



viation of Reii-al-Kottdb, that is, "the head or chief of secretaries or 

 writers." 



EFFERVESCENCE. The escape of bubbles of gas from a liquid. 

 The phenomenon is seen when marble or chalk is dropped into vinegar, 

 or when the cork of a soda-water or champagne bottle is removed. 



EFFLORESCENCE (from effloresce, to blow as a flower). A term 

 applied to the formation of small crystals on the surface of bodies, in 

 consequence of the abstraction of moisture from them by the atmos- 

 phere. Thus carbonate of soda and sulphate of soda, when exposed 

 to the air, part with their water of crystallisation, and crumble down, 

 or effloresce, to a white powder. Other salts on the contrary, such as 

 carbonate of potash and chloride of calcium, absorb moisture from 

 the air and become damp, or even liquefy in the water so absorbed. 

 This is called deliquescence (from deliqueo, to melt), and the salts are 

 called deliquescent, as in the former case they are termed efflorescent, 



EFFUSION. A term nearly related to DIFFUSION, and has refer- 

 ence to the velocities with which different gases pass through the 

 same small aperture into a vacuum. These velocities are stated l>v 

 Professor Graham ('Phil. Trans.' 1848) to be inversely as the square 

 roots of the densities of the gases. The lightest gas enters the mn*t 

 rapidly, and any change in the density of the gas has but little 

 influence on the rate of effusion, the volume efrused in a given time 

 being nearly uniform. The same law also applies to liquids in passing 

 through an aperture in a thin plate. In the case of gasei, Graham 

 made use of an aperture of about sJnth of an inch in diameter. In the 

 following table the numbers in the third column represent the rates of 

 effusion of different gases obtained experimentally, and it will be Been 

 that they coincide within the limits of experimental errors, with tho 

 relative rates of diffusion of the respective gases. 



Velocity of 

 Diri'u.ion. 



Hydrogen , , , , , , 3 81 

 Light carburetted hydrogen . . 1-S44 



Carbonic oxide 1-0149 



Nitrogen 1-0143 



Olefiant gu 



1-0191 



Oxygen 0'9487 



Protoxide of nitrogen . . . . 0-82 

 Carbonic add 0-812 



Rate of 

 Effusion. 

 3-613 

 1-823 

 1-0123 

 1-0164 

 1-0128 

 0-950 

 0.834 

 0-821 



[TRANSPIRATION.] 



EGG, WHITE OP. [AiBUHWf.] 



EGG TRADE. Apart from the interest belonging to eggs in con- 

 nection with natural history, there is much that is remarkable in their 

 relation to comment and manufactures. The egg trade is now one of 

 great magnitude. What the number of English eggs produced and 

 consumed, either as food or in manufactures, may be, it is impossible 

 even to guess ; for there are no returns which can apply to this sub- 

 ject ; but of foreign gg* we find that there have been imported the 

 following quantities in recent years : 



1844 , 

 1847 

 1850 , 

 1853 

 1856 , 

 1858 



67,000,000 

 77,000,000 

 106,000,000 

 123,000,000 

 117,000,000 

 135,000,000 



Theiie are principally obtained from France. The quantity imported 

 ill 1858 had a declared value of about 300,000!. 



Eggs are largely employed in the leather manufacture, in the con- 

 version of kid skins into leather for gloves and shoes. In one process 

 of the manufacture, yolk of egg is mixed with alum, salt, and flour in 

 a barrel, and the skins are agitated with this mixture for some time. 

 Much of the softness of good kid leather is due to this use of egg-yolk. 

 There is one leather-factory in Bermondsey where from 60,000 to 80,000 

 eggs are used for this purpose every year; they are imported from 

 France in the spring, and are kept good throughout the year in lime- 

 water. 



Mr. Cooley makes the following observations on the preservation of 

 eggs : " Eggs may be preserved for any length of time by excluding 

 them from the air ; one of the cleanest and easiest methods of doing 

 this is to pack them with the small ends downwards, in clean dry salt, 

 in barrels or tubs, and to place them in a cool and dry situation. We 

 have eaten eggs thus prepared that were more than twelvemonths old, 

 and that had been for some months on shipboard, in a tropical climate, 

 and which yet retained all the peculiar sweetness of new-laid eggs. 

 With a like intention, eggs are placed in vessels containing milk of 

 lirno, or strong brine, or are rubbed over with butter, lard, or gum- 

 ; all of which act by excluding the air. Eggs for keeping should 

 never be laid on their sides ; and when kept in the air, should be occa- 

 sionally turned to prevent the yolk attaching itself to the side, instead 

 'ing in the albumen. Some persons place the eggs in a netting, 

 or on a sieve or colander, and immerse them for an instant in a caldron 

 lifig water, before packing them away. The practice of packing 

 eggs in damp straw, or anything else that can convey a flavour, should 

 be carefully avoided ; the xhells of eggs are porous, and readily admit 

 the passage of gaseous substances, especially of fetid odours. It is 

 from inattention to this point that a large portion of the eggs im- 



ported from the coast of France have a less delicate flavour than those 

 of our poultry-yards. Damp dropped straw, as well as most other 

 organic substances exposed to warmth and moisture, readily ferment 

 or putrify ; and during fermentation, a considerable increase of tem- 

 perature takes place, as any one may readily perceive by examining 

 the common hotbeds in our gardens, which are merely masses of organic 

 matter in a state of decomposition. Eggs, as long as they retain the 

 embryo of the future chick in a vital state, possess in themselves a 

 certain degree of warmth, which tends materially to promote the de- 

 composition of the substances they are packed in, particularly in the 

 presence of moisture." In reference to the preservation of "eggs, it 

 may be stated that Mr. Jayne has patented a liquid for this purpose ; 

 consisting of two or three pounds of salt mixed with half a pound of 

 cream of tartar, and dissolved in water to a brine strong enough just 

 to float an egg. This liquid, it is stated, will preserve eggs fresh as 

 long as two years ; but Mr. Cooley is of opinion, that simple milk of 

 lime will answer quite as well. 



It affords a curious exemplification of the large scale on which the 

 consumption of apparently trifling articles is now conducted, that in 

 July, 1859, a suit in equity was tried between the inventors of two 

 eyy-beating machines. A patentee of a method of beating up the whites 

 of eggs complained of another machine-maker for infringing his patent. 

 The offender admitted the use, but denied tho validity of the patent; 

 and he brought forward proof that the inventors of two previously- 

 patented churns, had anticipated all, or nearly all, that was really 

 essential in the egg-beatiug machine. 



EGYPTIAN ARCHITECTURE. Tho architecture of almost every 

 civilised people can be traced to that of an earlier people or country, of 

 which it is an adaptation or development. The architecture of Egypt 

 is, however, an exception. It is the oldest architecture of which any 

 examples remain, or of which we have any record ; and it differs from 

 all other architecture in its distinctive characteristics. In magnitude, 

 solidity, and magnificence, it far surpasses that of every other country ; 

 but in unity of plan, grace of proportion, and [esthetic feeling, it will 

 not bear comparison with the architecture of Greece. The ancient 

 Egyptians appear in truth to have been not merely deficient in aesthetic 

 culture, but their mental and national peculiarities were adverse to its 

 reception. Further, they were controlled in all artistic work by 

 immutable hierarchic rule, and free mental development was therefore 

 impossible. The art of one age was, in a certain sense, that of all. If 

 there was change, it was due to a change of dynasty, and therefore to 

 a foreign influence, 



'Were we to treat Egyptian architecture chronologically, we might 

 divide it into the architecture of Lower, Middle, and Upper Egypt, and 

 of Nubia ; but we could not so treat it without entering into a fuluesa 

 and minuteness of detail which would be quite out of place in a general 

 sketch like the present. Within the limits assigned to us it will be 

 must convenient to describe broadly the several great classes of struc- 

 tures, and the chief architectural members. 



The most ancient edifices of Egypt are the pyramids, those of Gizeh 

 being the earliest, JJut these we shall do little more than mention 

 here, because, interesting as they are in themselves, they are structures 

 of RO very peculiar and distinct a nature as to have but little connection 

 with the architecture of the country in general ; being, when considered 

 with rel'ereuou to it, little more than unil'nrm and simple though enor- 

 mous masses. They are, in fact, greatly more important in an historical 

 and arclucological point of view than in one purely historical. Their 

 shape is so familiar to every one that it requires no description, but 

 may be defined as square in plan and triangular in section, its four 

 sides being as many triangles united so as to terminate in a point ; and 

 as the height is much less than the width of the base, each side con- 

 stitutes nearly an equilateral triangle. The extraordinary height and 

 magnitude of these vast erections are combined with imperishable 

 stability and solidity, the whole being nearly one entire mass of the 

 hardest materials, for the inner galleries and chambers form but mere 

 veins and cavities compared with the entire mass. For a descrip- 

 tion of them we refer to the article PYRAMIDS. For the same reason 

 that we do not stay to describe the pyramids here, we may leave to a 

 separate article those no less characteristic Egyptian monuments, the 

 lofty four-sided monolithic shafts known to us as obelisks. [OBELISKS.] 



The oldest really architectural Egyptian buildings are the great 

 temples, or temple-palaces like that of Karnak ; but as this enormous 

 edifice was really an aggregation of buildings, the growth of ages, of 

 which the nucleus appears to have been the sanctuary, built by Oser- 

 tesen, the great king of the 12th dynasty, whilst the great court in 

 front only dates from the 22nd dynasty, a clearer notion may bo 

 conveyed of the plan and character of an Egyptian temple by exami- 

 ning one of simpler form, though of later date. We select, therefore, 

 as our example the temple at Edfou, or Apollinopolis Magna, erected 

 under the Ptolemies, one of the largest and much the most 

 complete of any in Egypt. Its dimensions are given on the ground 

 plan. This it will at once be seen from the plan, was far more 

 varied and complex than the plan adhered to by the Greeks, which, 

 consisted merely of a cella, either surrounded entirely with columns, or 

 with columns only in front, or at both ends. Here, on the contrary, the 

 temple is placed within an enclosure, which forms also a court in front 

 of it, surrounded on three sides by colonnades ; and the entrance to this 

 court was through a colossal doorway, or propylon, placed between two 



