108 



KNOWLEDGE ♦ 



[July 14, 1882. 



these aud various microfungi they do rot want iutrud- 

 in-' into tiieir fermentations, and giving their liquids 

 a ^IaJ flavour. In other very numerous cases the 

 l*tr or wine seems all right at tirst, but will not 

 teep. Whether in cask or bottle, some of the intrusive 

 ferments continue in operation, either producing vinegar, 

 or some other substance with an objectionable llavour. To 

 minimise the danger, brewing should l>e carried on in pure 

 air, and with tlie greatest regard to cleanliness. Fer- 

 menting the wort in a warm temperature, as is common in 

 tliis country, is more favourable to the growth of the un- 

 desirable organisms than the cooler process so much 

 employed in Germany. It beer, made by " high fermen- 

 tation," that is at a warm temperature, and with the yeast 

 cells rising to tlie top, is intended to keep for a length of 

 lime, or to stand a sea voyage, it must be strong and well 

 hopped, the aromatic oil of the hop being unfavourable 

 to the growth of microferments. Besides getting sour, 

 l.eer and wine arc liable to turn ropy and putrid, 

 through the action of special ferments whose germs are 

 very widely diffused. Slender beaded organisms, straight, 

 curved, or spiral, some quiet, others in quick motion, 

 preside over these changes, producing what Pasteur calls 

 various " maladies " in the fluids they attack. The " low 

 fermentation " goes on slowly at low temperature, and the 

 veast falls to the bottom of the vessel. Tlie temperature 

 should be about 4.")° F., and great quantities of ice are 

 used in the German breweries to enable the process to be 

 carried on during the warmer months. The beer is also 

 kept in cool cellars, and Pasteur states that nearly 2 cwt 

 of ice is consumed in getting 22 gallons of beer ready for 

 sale. If well made and carefully bottled, this kind of beer 

 will keep without being of great alcoholic strength, or 

 highly hopped. 



If wine is likely to be affected by the intrusive fei'ments, 

 Pasteur recommends bringing it near the boiling point 

 after it is put into bottles. This kills the microferments, 

 and, if carefully performed, leaves the wine with a good 

 flavour, but it is said that when so treated it does not 

 improve with age. 



It is interesting to let a saccharine fluid spontaneously 

 pass into the acetous fsmientation and examine the orga- 

 nisms under the microscope. If a little yeast is used to 

 start the alcoholic fermentation, and the liquid is then left 

 for some time in a warm place and exposed to the air, it is 

 pretty sure to turn sour. From a wide-mouthed bottle con- 

 taining an ounce or two of a saccharine fluid so treated a 

 little ropy mass is taken from the bottom and found to be 

 couifKised of vast multitudes of minute beaded threads 

 thickly interlaced. Sometimes a leathery mass is found — 

 the so-called " mother of vinegar," or vinegar plant. 

 Many families make tlieir own vine/zar by its means. 

 They put it into a pretty strong solution of coarse brown 

 Kugar, and in a few weeks find it is turned to good 

 1-inegar, and the plant greatly increased in thickness. 

 It is then like a stout piece of wet buff leather, and easily 

 splits horizontally. If a small piece is jilaced in a bottle 

 such as is used for Pre.ston salts, in a solution of lump 

 sugar, a growth is soon obtained transparent enough for 

 convenient examination. After viewing it with a low 

 power, one of 400 or more diameters should be used. A 

 numljtr of ycas^like cells, a.ssociated with multitudes of 

 Ijeaded, rod like cells, are then seen to be immersed in a 

 mavs of tough, gelatinous matrix. If a vinegar plant is 

 taken out of a vessel, with a sufllcient depth of fluid to 

 ke«-p its under surface and part of its thickness conqjletely 

 submerged, and placed in a sliallowcr one, so that it is 

 much more exposed to air, it does not continue to carry on 

 tlic acetous fermentation, but i» soon covered with crops of 



blue mould. The sugar disappears, gets slowly burnt 

 up, but neither vinegar nor alcohol is obtained. In 

 some experiments by the writer, publislied in 18G5 

 by the Microscopical Society, it was found that vinegar 

 plants dried in an o\en, at a temperature too low to 

 burn them, were reduced to a state like dry gelatine, 

 which clicked when thrown upon glass. Exposed to 

 the air they absorbed moisture, and when thoroughly wetted 

 the various cells appeared uninjured, but most of them uo 

 longer produced the acetous fermentation. In one case, 

 the butyric fermentation occurred in a saccharine solution, 

 evidenced by the peculiar and very nasty smell of highly 

 rancid butter. In another case, after six months' immer- 

 sion, a dried piece of the plant began to form vinegar, and 

 produced loosely aggregated cells which carried on the 

 process. 



The same kind of cells may produce quite different effects 

 under varying conditions. They may take the oxygen they 

 want from the air, or, if that is excluded, obtain it by 

 decomposing some substance present. The number of new 

 combinations that may bo produced by partial decompo- 

 sitions and oxidations is indefinitely large, and may give 

 rise to "maladies" of beer, wine, butter, ic, aud in the 

 human organisms, to various diseases. 



WAS RAMESES II. THE PHARAOH 

 OF THE OPPRESSION? 



By Amkli.\ B. Edw.\hds. 

 IV.— THE CONSECUTIVE AND SYNCUEONOUS 



IT is difficult to make even the roughest historical calcu- 

 lation without some use of dates ; but, as I have 

 already said, no dates that can be applied to this early 

 epoch of Egyptian history are other than approximate. 

 \V'e may estimate the number of years whicli elapsed 

 between one given event and another given event, and wo 

 may thence calculate our way to a third event, and all 

 three conclusions may be relatively accurate ; but to label 

 any one of the three with a positive date i>.c. is, in the 

 present state of our knowledge, impossible. Still it is 

 necessary, if only in order to be intelligible, temporarily to 

 accept a fixed date of some kind ; and for this purpose I 

 propose to accept Mariette's date, ac. 1462, for tho 

 beginning of the XlXtli dynasty. Mariette, it should 

 be said, founded his chronological system on the 

 historical lists compiled by an Egyptian historian 

 named Manetho, who was high-priest of the Great Temple 

 of Jleliopolis and KeejK-r of the Archives, under Ptolemy 

 Philadelphus, u.c. 284-246. Manetho, though a native 

 Egyptian, wrote in Greek, which was the language of the 

 Ptolemaic court (just as Turkish, and not Arabic, is now 

 the language of tlie court at Cairo) ; and in Greek he com- 

 posed his famous "History of Egypt," whicli was either a 

 direct translation of ancient historical papyri, or an 

 original narrative based upon tliose early chronicles. This 

 invaluable work lias perished ; but some precious quota- 

 tions from it are found in the writings of Josephus, 

 Eusebius, and George the Syncellus before-mentioned. 

 Above all, the great clironological list of dynasties and 

 kings from Mena to Alexander is preserved entire in the 

 works of several Christian clironologibt.s. Following 

 this list, Mariette places the XlXth dynasty between 

 ac. 1462 and ac. 1288. The first three Pharaohs of this 

 dynasty were Rameses I., Seti I., and Pvamescs II. Tabu- 



