192 



SCIENCE. 



it, except to refer to it in a general way.* I am glad that 

 the discussion arising from Mr. Larkin's letter has fur- 

 nished such opportunity, and avail myself of it to give it 

 to " Science " for publication. Geo. W. Rachel. 

 New York, April 11, 1881. 



MICROSCOPICAL NOTES. 



Recent investigations respecting the pathological rela- 

 tions of diphtheria, and the discovery of a micrococcal or- 

 ganism in the false membrane, have made it almost certain 

 that the morbid poison which gives rise to the disease is a 

 parasitic organism. M. Talamon now states that he has 

 succeeded in finding this organism in eight cases. In the 

 condition of complete development they presented a char- 

 acteristic mycelium and spores. The former are tubes with 

 partitions from two to five thousandths of a millimetre in 

 length. These under favorable circumstances, elongate 

 and bifurcate, the bifurcations being characteristic in con- 

 sequence of their incurved branches, like the sides of a lyre. 

 In other conditions the mycelia do not become elongated, 

 although they multiply so rapidly as to cover the surface 

 of the cultivated liquid ; they remain short and assume 

 irregular forms, and give rise to numerous straight rods. 

 The spores are of two kinds, round or oval, which may 

 be termed the spores of germination, and rectangular 

 spores or conidia. The latter characterize the species. 

 They form small rectangles of various sizes, their length 

 being sometimes fifteen thousandths of a millimetre. 

 They may be isolated or united in festoons or zigzag 

 chains. At first homogeneous they soon become filled 

 with small round granules, highly refracting, and of the 

 size of ordinary micrococci. The round or oval spores 

 are those which by their elongation constitute the mycel- 

 ium. They appear as clear points, from three to five 

 thousandths of a millimetre in diameter, in the middle of 

 a mass of granular material. 



Animals and birds inoculated with these organisms all 

 died developing the characteristic false membrane. 



These facts are very important, and open up an en- 

 tirely new field of investigation, and M. Talamon already 

 hints that he has a clue as to the source from which 

 the organism is derived in the case of human infection. 

 We trust that those of our subscribers who possess mic- 

 roscopes will follow up the researches of M. Talamon, 

 which promise results of the highest value to science 

 and to humanity. 



NOTES. 



The bicaibonate of soda prepared by the Solvay process 

 contains from two to three per cent, ammonia, and is there- 

 fore not suitable for pharmaceutical use, and for certain 

 technological purposes. 



A Novel Ferrtc Hydrate. — C. Graebe has received 

 from the Baden Aniline and Soda works a reddish crystal- 

 line substance deposited in cast-iron vessels in which pot- 

 ash has been melted. It has the same composition as hema- 

 tite and gcxuhite, but its specific gravity is only 2.93. 



Chlorinated Derivatives of Carbazol. — On treating 

 carbazol suspended in acetic acid with chlorine, the 

 liquid turns blue, yellowish, greenish, and, lastly, red. If 

 the reaction is then interrupted the product is trichloro- 

 carbazol in white needles, melting at 185°. If the process 

 is continued for ten or twelve hours, hexachloro-carbazol is 

 produced, fusible at 225 . — W. Knecht. 



Presence of Alcohol in the Soil, the Water and 

 the Atmosphere. — A. Muntz has previously shown that it 

 is possible to detect exceedingly slight traces of alcohol by 

 converting it into iodoform. On concentrating the alcohol 

 in a small volume of water by means of fractionated distil- 

 lation, and using the microscope to verify the presence of 

 iodoform, he was able to recognize with ease i-300,oooth of 

 alcohol mixed with water. He has since improved the 



• "Science," Vol. I, p. 246, foot-note to the paper on Friedrich Mohr's 

 Life and Works; Scientific American Subfile nnnt No. 266, p. 4,241, in a 

 paper on 11 The Actual Figure of the Earth." 



process so as to detect quantities even -smaller than 

 1-1,000,000. During the last four years he has applied this 

 method to river, spring, and sea-water, as well as to rain 

 and snow. The results obtained leave no doubt of the 

 presence of a neutral body, more volatile than water, and 

 yielding iodoform. He thinks alcohol is the hydro-car- 

 buretted body present in the atmosphere, indicated by the 

 researches of Boussingault and De Saussure. Soils rich 

 in organic matter yield alcohol in such proportions that 

 its essential properties may easily be verified. 



New Synthesis of Desoxy-benzoin and Crysene. — 

 MM. Graebe and Bungener have obtained desoxy-benzoin 

 by causing the chloride of phenyl-acetic acid to react upon 

 benzol in presence of aluminium chloride. By the same 

 reaction, naphthalin being substituted for benzol, they pro- 

 duce benzyl-naphthyl-keton. They then reduce with hy- 

 driodic acid and phosphorus at 150 to 160°, and pass the 

 vapors of the carbide thus obtained through a red-hot tube, 

 when 4 atoms H are removed and chrysene remains. 



Certain Phenomena of Optics and of Vision. — M. 

 Tteve mentions the fact that the flame of a lamp appears 

 brighter, and that a vertical shaft, a post, or mast is seen 

 more distinctly through a vertical than through a horizontal 

 slit, whilst a house, a landscape, or the disk of the sun or 

 moon is perceived more clearly through a horizontal slit. 

 He finds similar differences in photographs according as 

 the light passes from the object to the plate through a ver- 

 tical or a horizontal slit, and ascribes the results to the ac- 

 tion of diffused light. 



Copal varnish for mounting objects for the microscope 

 has been suggested by Mr. Julien Derby of the Ouekett 

 Club, who states that Mr. Van Heurck, of Antwerp, who 

 first used it, has met with much success in mounting dia- 

 toms with that medium. This varnish is used about the 

 consistency of oil and should be of that brand known as 

 " pale copal." It has about the same refractive index as bal- 

 sam, and is free from bubbles. Drop the copal over the ob- 

 ject and slightly heat over a spirit lamp. In some cases a 

 cover can be dispensed with, as it soon takes the consis- 

 tency of amber, and is hard enough to sustain wiping and 

 brushing with a soft brush with impunity. 



Widening of the Rays of Hydrogen. — The nebulous 

 expansion of the spectral rays of hydrogen, noticed on in- 

 creasing the pressure of this gas in a Geissler tube, is still 

 ascribed to the influence of the pressure, though Dr. Shus- 

 ter, Secchi, and others have shown that it is not possible to 

 alter the pressure of a gas without at the same time affect- 

 ing the resistance of the medium, and in consequence the 

 temperature of the spark which traverses it. C. Fievez has 

 undertaken to examine separately the influence of the dif- 

 ferent agents, temperature, pressure, direction of the cur- 

 rent, etc., which have been suggested as contributing to 

 produce this phenomenon. He finds that the widening of 

 the hydrogen rays is correlative to the rise of temperature. 

 We may affirm that the temperature of a celestial body is 

 higher than that of another if its hydrogen rays are broader. 



Reciprocal Displacements of the Hydracids. — The 

 action of the hydracids upon the salts formed by the halo- 

 gens is in general the inverse of that of the elements them- 

 selves. Thus hydriodic acid expels hydrochloric acid from 

 the metalic chlorides and hydrobromic acid from the brom- 

 ides, whilst hydrobromic acid also liberates hydrochloric 

 acid from the chlorides. The chlorides in general are de- 

 composed by hydrobromic acid, and this decomposition 

 preponderates according to the thermic value of the princi- 

 pal action. But the bromides may also be decomposed, 

 though less readily, by hydrochloric acid. This inverse 

 action previously pointed out by M. Hautefeuille in the salts 

 of silver at a red heat, and by the author in the moist way, 

 has lately been observed anew by M. Potilizinc, but it is in 

 no way contrary to thermo-chemical principles. It results 

 from the existence of secondary compounds, partially dis- 

 sociated, which intervene with their peculiar heat of forma- 

 tion. The theory of these reciprocal actions and equilibria 

 is always the same. In every case we have to do with a 

 principal re-action, foreseen by the thermic theory, and a 

 perturbation equally foreseen by the same theory, of which 

 it is a necessary confirmation. — M. Berthelot. 



