Part 53

=BACON= (b[=a]'-kn). [W., baccun, prob. from Ger., bache, a wild sow; "old Fr., for dried flesh or pork"--Craig.] The flesh of swine salted and dried, and subsequently either smoked or not. The term is usually restricted to the sides and belly so prepared; the other parts of the animal having distinctive names. Sometimes, though rarely, the term is extended to the flesh of bears, and of other like animals, cured in a similar manner.

_Qual., &c._ When bacon has been properly prepared from young and well-fed animals, and is neither 'stale' nor 'rusty,' it forms a very wholesome and excellent article of food, especially adapted for a light or hasty meal, or as a relish for bread or vegetables. For persons with a weak stomach, and for invalids, great care should be taken to cook it without injuring its flavour, or rendering it indigestible. This is best effected by cutting it into slices of moderate thickness, and carefully broiling or toasting it; avoiding dressing it too hastily, too slowly, or too much. The common practice of cooking it in almost wafer-like slices, until it becomes brown and crisp, renders it not merely indigestible, but also a most fertile source of heartburn and dyspepsia. Fried bacon is remarkably strong, and is hence more likely to offend the stomach than when it is broiled, or preferably toasted before the fire; the last being, of all others, the best way of dressing it so as to preserve its delicacy and flavour. Gourmands, however, often esteem, as 'une bonne bouche,' bacon dressed in the flame arising from the dropping of its own fat.

_Choice._ Good bacon has a thin rind, and an agreeable odour, the fat has a firm consistence and a slightly reddish tinge; the lean is of a pleasing red colour, is tender, and adheres, whilst raw, strongly to the bone. When the fat is yellow, it is either 'rusty' or becoming so, and should be avoided. The streaky parts are not only those which are most esteemed, but are the most wholesome.

Bacon should be broiled or toasted in front of the fire. The rashers should be in thin slices, and the rind should be removed. The melted fat from the bacon should never be wasted. To partake of all broiled meats in perfection they should be served up as soon as they are taken off the gridiron.

=BACTERIUM= (BACTERION, a little rod). Since the publication of the researches of Professor Cohn, of Breslau, upon the nature of this organism, the idea previously entertained by Ehrenberg and others as to its animal origin has been long abandoned, and microscopists now very generally regard it as belonging to the vegetable kingdom. It is probably one of the lowest and most simple forms of vegetable or animal life, and consists of an envelope more or less enclosing protoplasm--the nitrogenous substance from which the cell nucleus is formed. Dr Lionel Beale very carefully crushed a very large bacterium while under observation by the microscope, and when the external membrane was ruptured the protoplasm was seen to escape, and to exhibit what Dr Beale regards as vital movement. In form, bacteria may be either globular, rod-shaped, egg-shaped, or filamentous. Cohn has described a variety presenting the appearance of beaded chains, or aggregations.

Bacteria vary considerably in size, some being as much as 1/3000th of an inch in length, whilst others are less than 1/10000th, and are only visible by the aid of a glass of very high power, such as the 1/50th of an inch objective. Dr Beale says, "The germs from which the little particles spring are far more minute and more difficult to identify. They appear as minute specks, the largest of them exhibiting a circular outline, and probably being spherical. The smallest are too minute to be discerned with the highest magnifying powers at our command. If a specimen of fluid in which these particles are rapidly growing and multiplying be carefully examined, many points will be observed to appear from time to time. After watching with great care for a considerable time a given spot I have assured myself that new particles actually come into existence; and that one does not, after intently watching for a time and concentrating the attention upon a certain space, merely see one coming into view one after another, as star after star. The material in which the minute germs of bacteria are imbedded, and which, at least in part, consists of formed material produced by the bacteria, is much softer than the matter of which the capsule of fungi consists. It is, perhaps, almost as soft as mucus. I believe that even the most minute bacterium germ is surrounded by a layer of such soft formed matter, in which very minute particles of bioplasm (protoplasm) divide and subdivide before they attain even the 1/100000th of an inch in diameter. When, therefore, bacteria in an early stage of development dry, it is not possible to identify them. When moistened, the dry mass swells up, and the bioplasm in the soft mucus-like matter grows, each particle producing a fresh investment of formed material, and then if the conditions are favorable, the germs either at once divide and subdivide for a time, or grow into perfect bacteria, which move freely and grow and multiply in this more advanced stage of development."

Bacteria increase by bisection, and when the surrounding conditions are favorable their rate of production is marvellous. It has been computed that an individual bacterium will generate nearly 17,000,000 of its fellows within twenty-four hours. The very probable vegetable origin and nature of bacteria insisted upon by Professor Cohn not only appears to derive great support from his researches into the metamorphoses they undergo during development, &c., but also from their behaviour with certain chemical reagents. For instance, it was found that boiling them in solution of potash had no effect, and also when treated with sulphuric acid and iodine they deported themselves somewhat as cellulin does under like circumstances; although from their extreme minuteness any changes that take place in their tissue are very difficult to observe. Another remarkable analogy presented between bacteria and plants is the manner in which they both assimilate the elements of which they are built up; for they derive their nitrogen not from previously existing albuminous compounds, but from ammonia.

They may be made to develop themselves in any fluid if the fluid contains an organic substance in which carbon is present, a nitrogenous substance which need not be organic, and a phosphate. They appear to derive their carbon by the decomposition of almost any substance, containing this element except carbonic acid, and they will obtain their nitrogen from a nitrate, the nitrate becoming reduced to the state of a nitrite. A knowledge of these facts will of course indicate the method to be followed if we wish to obtain bacteria. All that we have to do is to prepare a liquid that fulfils the conditions just stated. Dr J. Burdon Sanderson gives the following formula for one:--Phosphate of potassium 1/2 per cent., sulphate of magnesium, 1/2 per cent., dissolve in water having a trace of phosphate of calcium in suspension, and then add a per cent. of tartrate of ammonium, and boil the mixture. If properly boiled the liquid will be free from bacteria; but the contact of almost any organic substance, for example, a drop of water, a pinch of hay, a morsel of meal, &c., will cause their appearance.

The tenacity of life exhibited by the bacteria is extremely great. Dr Beale says, "Extreme dryness does not destroy them, and they withstand a temperature far below the freezing point; and that under adverse circumstances they remain dormant, and are not destroyed by a degree of heat which is fatal probably to every other living organism." Bastian says that the germs of bacteria are destroyed at a temperature of 160° F., but others are of opinion that under certain circumstances these germs are not killed at 212°, and that they may increase and multiply after having been exposed to this degree of heat. Professor Tyndall indeed has shown that in one experiment heating for a quarter of an hour at a temperature of 230° F. was insufficient to destroy them, whilst in another the five minutes' exposure of an atmosphere containing them to the incandescence of the voltaic current failed to kill them.

Cohn relates that manufacturers of pots of preserved peas at Lubek have since 1858 been obliged to cook them in a solution of 28 per cent. of salt, at a temperature of 226° F., to prevent the putrefaction of their contents, as in warm years nearly half the pots were found to be spoiled. In experiments made in conjunction with Dr Hare, Cohn found that in infusions boiled for less than fifteen minutes organisms were, without exceptions, developed. Somewhat lower temperature proved fatal to the great majority of bacteria. Those that survived were all found to belong to the genus _Bacillus_, and among _bacilli_ to the species _Bacillus subtilis_.

The experiments of Drs Ferrier and Burdon Sanderson would seem to show that bacteria do not nominally exist in the fluids and tissues of the body, but that their presence in the animal fluids may be traced to external surface contamination with ordinary water, the extent of their development being in proportion to the amount of the contamination. They contend that different varieties of water possess different degrees of what they term the 'zymotic power.' They examined the waters supplied by the several London water companies, and they found them to consist of varying degrees of bacterian impurity. They assert that all except freshly distilled water teems with invisible germs of bacteria. Writing of the universality of the presence of bacteria and bacterian germs, Dr Beale remarks:--"It would be difficult to say where bacterium germs do not exist. In air, in water, in the soil adhering to tiny particles of every kind, in every region of the earth, from the poles to the equator, they are found. In the substance of the tissues--nay, in the cells of almost all plants, and in the interstices of the tissues of many animals--bacteria germs exist. I know not what part of the body of man and the higher animals is entirely destitute of particles which under favorable circumstances develop into bacteria. Upon the skin and the surface of the mucous membranes they exist in profusion, and they abound in the mouth and in the follicles and glands."

Dr Eberth, of Zurich, states that he has found on ordinary sweat small oval-shaped bacteria which are frequently united in strings of two or three, and endowed with rather active movements. The author thinks that they very likely conduce to produce certain chemical modifications of sweat.

Drs Ferrier and Sanderson appear to have satisfactorily proved that fungi are not developed from microzymes, and that their apparent association is one of juxtaposition only. They give the following reasons for adopting this conclusion:--(1) The quick appearance of _torula_ cells in Pasteur's solution whenever it is exposed to the air, and the rapid development and luxuriant fructification of the higher form (_penicillium_) show that so far as the chemical composition of the liquid is concerned, there exist in it all the conditions favorable to the process. (2) When precautions are taken to prevent contamination by impure surfaces or liquids, the development which ends in _penicillium_ goes on from first to last without the appearance of microzymes. (3) Whenever it is possible to impregnate the test-liquid with microzymes, without at the same time introducing torula cells or germs, the development of the former begins and continues by itself without any transformation into the latter. Thus _fungi_ are not developed, notwithstanding the presence of microzymes in the same liquid in which, microzymes being absent, but air having access, they appear with the greatest readiness. As we have already seen the germs of bacteria exist largely in air; the experiments of Hiller, of Berlin, would seem to negative the theory of Ferrier and Sanderson, as they tend to show that bacteria have little influence on putrefaction.

We are indebted to Dr Lionel Beale for these illustrations, which are taken from his very interesting work on 'Disease Germs.'

Hiller's experiments tend to show that putrefaction is independent of the presence of bacteria, that bacteria can develop in liquids such as urine without producing its decomposition, and that the degree of their development and the rate of their multiplication depend upon the amount of assimilable material.

The following is the definition given to the word 'microzyme' (which occurs above) by its originator, Dr Sanderson: "I proposed the word 'microzyme' as a convenient general term for the first organic forms which present themselves in organic nitrogenous liquids when about to undergo spontaneous decomposition."

From the experiments of Béchamp it appears that under some circumstances the mother of vinegar, a conglomeration of microzymes, can be transformed into bacteria, and under other circumstances into a cellular ferment which can excite normal alcoholic fermentation in cane sugar. Subsequent researches have shown that the converse of this is also true, and that the cellular ferment may be transformed into microzymes and bacteria.

A mixture of starch and yeast kept at a temperature of 24° to 35° soon liquefies, and the yeast undergoes remarkable changes. The cells swell, become transparent, and gradually disappear. Myriads of microzymes of great agility spring into existence, then vibrios appear, and as these increase the microzymes diminish. The vibrios in their turn are succeeded by myriads of bacteria, and finally the bacteria disappear, leaving nothing but microzymes, single or coupled together. During these changes a small quantity of gas is disengaged, no butyric acid is formed, and but little acetic or lactic acids.

As then the mother of vinegar when changed into bacteria becomes lactic or butyric ferment, and when transformed into cellular matter becomes alcoholic ferment, and as beer yeast becomes lactic or butyric ferment when reduced to microzymes, vibrios, or bacteria, it is evident that the property of being a ferment of any particular nature does not depend essentially upon the nature of the ferment, but upon its organisation or structure.

A contributor to the 'Medical Times and Gazette' of February 2nd, 1878, advances the opinion that many of the bacteria are only parts of a plant which has other forms and other modes of growth and propagation when not confined to the living organism or to fluids, and regards the bacterium as a transitional or provisional and not as a permanent form, but an abnormal phase of life thrust upon the plant by accident.

=BACTERIA AS ORIGINATORS OF DISEASE.=--The researches of many eminent microscopists and physiologists afford abundant evidence of the presence of bacteria in the blood of persons affected with various infectious diseases. For instance, Core and Feltz, of Strasbourg, found a linked bacterium in the blood of those attacked with septicæmia, typhoid, and puerperal fevers. The same investigators also discovered bacteria in the blood of patients suffering from scarlet fever; this blood when injected into the veins of rabbits set up a feverish disease that proved fatal.

Again, in the blood of man and the sheep attacked with smallpox, a bacterium of the globular or sphere-shaped variety was found by Keber, Hallier, and Zurn.

Bacteria have also been found in the blood during measles, and in the splenic apoplexy of sheep and cattle. They have likewise been identified in diphtheritical exudations both from the kidneys and womb, as well as in the blood during an attack of rheumatic fever, and they are undoubtedly present in the same fluid during many feverish disorders. Drs Lewis and Cunningham failed to discover them in the blood of cholera patients. Professors Cohn and Koch stand prominently forward as the advocates of the germ theory of disease by bacteria. Professor Cohn divides the bacteria into groups, genera, and species, and assigns to each species a different function.

For instance, he considers the ferment of contagion to be due to the presence of a variety of the sphere-shaped bacterium--one of his groups. He divides the whole group into three--the chromogen, zymogen, and pathogen, the bacteria of pigmentation, of fermentation, and of contagion, respectively. He says those organisms are exceedingly minute, darkish or coloured granules, so small as to be immeasurable. They frequently present the appearance of beaded chains or the form of aggregations. They are motionless and are occasionally found with the _Bacterium termo_ in putrefying organic liquids.

Messrs Chauveau and Sanderson have discovered a bacterium in vaccine lymph which believers in the germ theory class among the pathogen bacteria, and which they have named the _Micrococcus vaccinæ_. Amongst the pathogen bacteria they also include the _Micrococcus dipthericus_ and _Micrococcus septicus_, the former found in the epithelium of certain organs during certain forms of pyæmia, and the latter in the miliary eruption of typhus, pyæmia, and other diseases. The chromogen or pigmentary bacteria have occasionally been the means of working miracles. Several instances of bread exuding blood, under supernatural circumstances, are related by Rivola. Ehrenberg found this colour on some bread in the house of a patient who had died of cholera, and he ascertained the pigment to be due to the presence of the _Monas prodigiosa_, small round bodies which Professor Cohn classes with the micrococci, a variety of the sphere-shaped bacterium.

The recent investigations of Koch were directed to the cause of splenic fever, and Cohn on examining his specimens found that they were examples of Bacteria of the species called _Bacillus anthracis_, which seems to present little or no difference to the _Bacillus subtilis_ of hay infusions. Koch found that _bacilli_ increase with enormous rapidity in the blood, and in the fluid of tissues of living animals, by developing in length and dividing transversely. The animals employed were chiefly mice, and a small incision being made at the root of the tail, as minute a drop as possible of the fluid containing the _bacilli_ was injected into the system. The spleen invariably became enormously swollen, and filled with a large number of crystalline-looking rods of varying size, never exhibiting movement or spore formation; they increased in numbers solely by division. The number of _bacilli_ found in the blood varies in different animals; thus in the guinea-pig it was enormous, sometimes exceeding that of the blood-corpuscles; in the rabbit much smaller, so that sometimes several drops had to be examined before any were found, in the mouse often _nil_. In the blood of dead animals or other suitable fluids the _bacilli_ grow to very long straight leptothorax-like filaments (within certain limits of temperature, and with the presence of air), while the formation of numerous spores goes on at the same time.

Kohl believes that it is to the presence of the spores that the occurrence of splenetic fever appears to be referable. When living, inoculation with them always produced the disease; but if killed, as by drying, or a high temperature, inoculation failed; it was necessary either that living spores should be present, or that the filaments should be capable of generating spores, in order that the disease should be propagated by inoculation.

Koch tried whether the poisonous bacilli spores could gain entrance through the digestive organs, but found that mice and rabbits could eat them with impunity. Koch draws attention to the similarity of splenic fever to typhus and cholera. He says it presents analogies to typhus in its dependence on soil-water, its preference for low grounds, its sporadic occurrence throughout the year, and its development into an epidemic in the late summer and autumn. Like cholera, again, he says, it is connected with soil-water, and it also agrees with cholera in the point which has been so well made out by Pettenkofer, that on board ship an interval of three or four weeks is sufficient to prevent its further development.

Hence Koch is disposed to hope that the contagium of typhus and cholera may still be discovered in the form of some _Schizophyte_ or spheroidal bacterium, though practical observers have hitherto sought for them in vain.

Many pathologists, however, refuse to accept the accuracy of these deductions, and regard the presence of bacteria in the blood and tissues during disease as of no significance; whilst they deny that it is satisfactorily proved that they are the cause of disease.

Dr Lionel Beale says:--"Changes in the processes of digestion are soon followed by the multiplication of bacteria in every part of the alimentary canal, and within a few hours countless millions may be developed. They multiply in the secretions under certain circumstances, almost as soon as these are formed, and I have adduced evidence to show that bacteria germs exist even in healthy blood. In the very substance of some cells I have seen them, and in many cases in which little granules have been discerned in connection with bioplasts. There is reason to believe that some of them are really bacteria germs, passive as long as the higher life is maintained in its integrity, but ready to grow and multiply the instant a change favorable to them, and adverse to us, shall occur."

And again he remarks:--"Bacteria prey upon morbid structure, and upon the substances resulting from the death of bioplasm (protoplasm). We ought not, therefore, to be surprised at their existence in disease. They are found in great numbers amongst pus-corpuscles which have ceased to live, and they grow and multiply with great rapidity in fluids which contain disease germs, as soon as these begin to lose their specific powers and to undergo decomposition." See GERMS.

=BAD''GER= (b[)a]j'-[)e]r). _Syn._ ME'LES, L.; BLAIREAU, Fr.; DACHS, Ger. The _ur'sus me'les_ (Linn.), one of the plantigrade carnivora, a burrowing nocturnal animal, common in Europe, Asia, and North America. Since the extirpation of the bear, the badger is the sole representative of the ursine family in our indigenous zoology. Its habits are "nocturnal, inoffensive, and slothful; its food consists of roots, earth-nuts, fruits, the eggs of birds, insects, reptiles, and the smaller quadrupeds; its noxious qualities are consequently few and of slight moment, and by no means justify the exterminating war unintermittently waged against it." (Brande.) Its "muscular strength is great, its bite proverbially powerful; and a dog must be trained and encouraged to enter willingly into combat" with it. (Id.)

_Uses, &c._ The flesh of the badger is prized as food; the skin used for pistol furniture; the hair made into brushes. The American badger is commonly called the GROUND-HOG. The Cape badger produces HYRACEUM (which _see_).

=BAD'IANE= (-e-[)a]hn). [Fr.] _Syn._ BAD'IAN, B.-SEED. Star-anise seed.

=BADI''GEON= (b[)a]-d[)i]zh'[=o]ne; b[)a]d'-e-zh[)u]n[double-dagger], or b[)a]-d[)i]j'[)u]n[double-dagger]--Smart). Among operatives and artists, any cement used to fill up holes and to cover defects in their work. Among statuaries, a mixture of plaster and free-stone is commonly used for this purpose; among joiners and carpenters, a mixture of sawdust and glue, or of whiting and glue; and among coopers, one of tallow and chalk. The name is also given to a stone-coloured mixture used for the fronts of houses, and said to be composed of wood-dust and lime, slaked together, stone powder, and a little ochre, umber, or sienna; the whole being mixed up with weak alum water to the consistence of paint, and laid on in dry weather.