HARD WICKE'S SCIENCE- G OSSIP. 



149 



3. M. aurantiacus, Cohn. 



Baderidium aurantiacitm, Schroter. 



Cells oval, about i J /u long ; on a solid substratum 

 in orange-coloured drops and spots, which at last 

 coalesce into equal-sized patches. On nutritive solu- 

 tions it forms a golden-yellow skin. 



On cooked potatoes and eggs. 



Colouring matter soluble in water. 



4. M.fiilvits, Cohn. 



Cells round, about i| fx. in diameter, at first forming 

 rusty conical tolerably firm drops of \ mm. in thick- 

 ness, which increase and finally present extended 

 gelatinous masses. 



On horse-dung. 



5. M. chlorinus, Cohn. 



Cells round (?), forming yellowish-green or sap- 

 green mucous masses, or in fluids sap-green layers, 

 which by degrees colour the whole fluid yellow-green. 



On cooked eggs. 



The colouring matter is soluble in water ; it is not reddened 

 by acids. 



6. M. cyaneiis, Cohn. 



Baderiditnn cyaneum, Schroter. 



Cells elliptic ; producing on slices of potato an 

 intense blue, which penetrates also into the interior, 

 or even to the opposite side of the slice. In fluids it 

 forms a Zoogloea, which at first is colourless, then 

 bluish-green, and at last intense blue. 



On cooked potatoes. 



The colouring matter is soluble in water ; the solution is at 

 first verdigris-green, but afterwards usually becomes clear blue. 

 It is coloured intense carmine by acids, and then by alkalies 

 blue or sap-green respectively. In the spectroscope it shows no 

 absorption bands, but only a darkening of the less refractive 

 half. 



7. M. violaceus, Cohn. 



Bacteridiiim violaceicrii, Schroter. 



Cells elliptic, larger than those of AT. prodigiosns, 

 occurring in bright violet-coloured gelatinous drops, 

 which unite to form larger spots, reaching 6 mm. in 

 diameter. 



On cooked potatoes. 



B. — Species producing Fermentatiox. 



8. AT. Jirccc, Cohn. 



Cells round or oval, i'25-2 ju in diameter, isolated 

 or concatenate or forming a Zooglcea on the surface 

 of the fluid. 



In urine. 



M. urecT is the ferment of ammonia fermentation. If fresh 

 urine is allowed to stand exposed at a sufficient temperature 

 (30° C), it loses its acid reaction after a few days, becomes 

 neutral, and finally alkaline, while the phenomena of fermenta- 

 tion are observed. The urea disappears and is changed into 

 carbonate of ammonia, while at the same time alkaline urates 

 and phosphate of ammonia and magnesia are eliminated. This 

 decomposition takes place only when the Micrococcus is de- 

 veloped in the fluid. 



9. M. Crepiiscuhim (Ehrenb.), Cohn. 



Monas Crepuscuhun, Ehrenb. (Infusionsth. ; pi. I., 

 fig. I). 



Cells round or shortly oval, very small, scarcely 

 2 /i in diameter, isolated or forming a Zooglcea, 

 In and on various infusions and putrefying fluids. 



r The common form of Micrococcus, which appears in all 

 sorts^of decaying substances and in infusions, ia company with 

 Bacterium Tcrmo. 



10. M. candidus, Cohn. 



On cooked potato-slices, forming snow-white 

 points and spots. 



C. — Pathologically active Species. 



11. M. VaccJncB, Cohn. 



Microsphcera VaccincE, Cohn. 



Cells round, J to 5 ^ in diameter, isolated or united 

 in chains and heaps of two or more, also forming a 

 Zooglcea. 



In fresh lymph from cow or human pocks, as also 

 in the pustules of true small-pox. 



According to many undoubted investigations, J/. Vaccina: 

 must be regarded as the active element of vaccine lymph ; it is 

 by its means that the infectious principle is conveyed in cases 

 of small-pox. By filtering the lymph, the solid constituents can 

 be separated from the fluid ; on using the latter for inoculation, 

 no effect is produced, while inoculation by the former regularly 

 excites the production of pocks. Moreover, that the Micrococci 

 and not, as might be suggested, the lymph-cells are the effective 

 constituents of ihe solid residuum, follows from the fact that 

 lymph, which has been exposed to the air for some time, grows 

 gradually less effective. For it begins to putrefy, and as the 

 process of decay advances, the Micrococci disappear more and 

 more, under the influence of the putrefactive bacteria. 



12. M. diphtheritictis, Cohn. 



Cells oval, '3-1 \x long, single or concatenate, or 

 forming bundles and colonies of various shapes. 



On the so-called diphtheritic membranes, which are 

 found especially on the mucous surfaces of the throat, 

 the pharynx, the air-passages, &c., but also appear on 

 those of the sexual and digestive organs, as well as 

 on wounds, &c. 



This Schizomycete is of extraordinarily great pathological 

 importance. For the disease spreads itself, from the centre of 

 its first introduction, through the lymphatic vessels and the 

 tissue which surrounds them, into the connective tissue, the 

 kidneys and the muscular tissue, and at last reaches even the 

 blood-vessels, where it produces the greatest destruction. The 

 fungi stop up the capillaries and thereby rupture them. Even 

 the thinner bones and cariilage are destroyed by the diphtheritic 

 processes. The consequences of the introduction of these fungi 

 arc therefore enormous. 



13. M. septiais (Klebs), Cohn. 



Alicrosporon septiaim, Klebs. 



Cells roundish, J p. in diameter, united in chains or 

 heaps, or forming a Zoogloea. 



On wounds, especially in all the affections which 

 are named pyaemia and septicaemia. 



In the various suppurations and putrefactions of the body, in 

 decomposition and poisoning of the blood, the Micrococci play 

 an important part. Whether all the manifold phenomena are 

 caused by M. septicus, or several species are not rather con- 

 cerned in their production, is questionable. In wounds, even in 

 the secretion from the fresh surfaces, we find Micrococci, which 

 quickly multiply, produce inflammation and fever, and penetrate 

 deeper and deeper, destroying the tissues in their course. If then 

 they reach the blood-vessels, there arise stoppages and suppura- 

 tions ; the same phenomena are observed in the lungs and 

 the liver. 



