104 



CHEMISTRY. (NEW SUBSTANCES.) 



rapid according a? the surface of contact with 

 the air is increased. Solutions of radium salts 

 hehavu in an analogous manner. .From these ob- 

 M-rvatioiis the authors deduce a theory which ex- 

 plains various phenomena of radioactivity. As- 

 suming that each atom of radium acts as a con- 

 tinual and constant source of radioactive energy 

 without knowing precisely whence this energy 

 comes, they find that that of it which is accumu- 

 1-ited in a body from a mass of radium tends to 

 di-ipate itself in two ways: 1. By radiation 

 nays charged and not charged with electricity). 

 Hv conduction to a body in contact or trans- 

 mission from particle to particle through the me- 

 dium of gases and liquids (induced radioactivity). 

 The phenomena are similar in their manifesta- 

 tions to those of heat under similar conditions, 

 and the explanation offered is analogous to that 

 given for them. 



M. Henri Becquerel has observed that metals 

 receiving the direct rays from a radioactive sub- 

 stance appear to give off a secondary radiation, 

 the penetrating power of which is more feeble 

 than that of the primary rays, and is analogous 

 to the same property of the secondary Kontgen 

 ravs discovered by M. SSagnac. The effect of the 

 secondary radiation is such that a metallic plate 

 placed upon a photographic plate, instead of act- 

 ing as a screen to arrest the radiation from the 

 source, gives, on the contrary, a stronger impres- 

 sion. 



Prof. Marckwald, of Berlin, having inferred 

 from the experiments of P. and S. Curie, Giesel, 

 and others, that the barium salt extracted from 

 pitchblende contains the radium salt as an iso- 

 morphous constituent, and that the process used 

 by these workers for separating a strongly radio- 

 active salt from the barium compound is proba- 

 bly similar to that in use for isolating the con- 

 stituents of an isomorphous mixture, fractionally 

 crystallized from water the barium chlorid pre- 

 pared from pitchblende. He found that pure 

 barium first separated, ard then a material, 

 probably the eutectic mixture, which was very 

 rich in the radioactive component. The most 

 strongly radioactive fractions had the power of 

 immediately discharging a charged gold-leaf elec- 

 troscope when at the distance of half a meter from 

 the latter, and when preserved under colored glass 

 soon turned to a deep-brown color. The radio- 

 active substance was strongly luminescent in a 

 dark room, and on interposing the hand between 

 the preparation and a barium chlorid platino- 

 cyanid screen, the bones of the fingers were seen 

 sharply delineated on the screen. In the course of 

 his address at the British Association, the author 

 exhibited several preparations of " phototropic " 

 substances, compounds which changed color on 

 exposure to sunlight and recovered their original 

 tint on preservation in a dark place. He re- 

 marked that the rapidity of change in either di- 

 rection is considerablv enhanced by the tempera- 

 ture. 



In an investigation of the physiological action 

 of radium rays, by MM. Henri Becquerel and P. 

 Curie, radifcrous barium ehlorid carried on the 

 arm in a thin gutta-percha envelope caused at 

 first a slight burning of the skin, resembling a 

 burn, but without pain. After a few days the 

 red area increased and the skin was broken, and 

 a sore still remained fifty-two days after the 

 action of the rays. The effects were*considerably 

 stronger and exhibited greater penetrative power 

 when more active material was employed. 



M. Henry Becquerel concludes a summary of 

 the studies of this subject with the remark that 

 they show that " a new order of phenomena has 



arisen from the study of a new property of mat- 

 ter radioactivity." 



New Substances. On submitting the three 

 varieties of sulfur to the action of liquefied am- 

 monia at 80 C., M. Moissan obtained no re- 

 action, but on allowing the temperature to rise 

 slowly, solution occurred, at different tempera- 

 tures, ranging from 38 to 11.5 with the dif- 

 ferent varieties. From this solution a new com- 

 pound, sulf ammonium, was obtained, of a dark- 

 red color, and having at 23 the composition 

 (N.H 3 ) 2 S; at 20 (NH 3 ) 2 S.2NH 3 , which is com- 

 pletely dissociable at the ordinary temperature 

 and pressure, and possesses the property of being 

 able to add sulfur in the cold to a large number 

 of simple and compound bodies. 



In the description of some new organo-metallic 

 compounds of mercury, MM. Auguste Lumiere, 

 Louis Lumiere, and Che vro tier represent that 

 when alkali phenol disulfonates react with mer- 

 curic oxid, compounds are formed of great solu- 

 bility and presenting some peculiar reactions. 

 They are, not precipitated by soda, hydrochloric 

 acid, or ammonium sulfid. Their taste is pure- 

 ly saline, and not metallic, as is usual w r ith mer- 

 cury salts. The solutions possess great antiseptic 

 power. 



The fact that continuous beating of the pulp in 

 the making of paper produces a transparent and 

 elastic mixture which hardens on drying and 

 greatly strengthens the paper has been utilized 

 for the production of a new economical substance. 

 This substance, cellulith, is prepared by a process 

 exclusively mechanical: a beating of the pulp for 

 a much longer time than is necessary for the 

 production of mere paper. After such beating, 

 which may last for from forty to one hundred and 

 fifty hours, until a homogeneous mixture having 

 no trace of fiber appears, the air in the substance 

 is removed by beating for two more hours; what 

 coloring matter may be desired is added, and 

 then the substance is heated. The hot cellulose 

 liquor passes into a vessel having a perforated 

 bottom, through which it drips. On evaporation 

 of the water the pulp hardens, gradually attain- 

 ing the consistency of horn, and having a specific 

 gravity of about 4. Cellulith may be worked as 

 horn or ebonite is. Combined with sawdust and 

 30 per cent, of lampblack, a kind of dark ebonite 

 is formed, which is dense and capable of being 

 polished. 



In an account of the hexafluorid of sulfur 

 published in 1900, M. Moissan mentioned that 

 other bodies were formed at the same time con- 

 taining sulfur and fluorin. He has since, with 

 M. Lebeau, made a further contribution to the 

 subject. The compound described is sulfurous 

 fluorid, SOoF 2 , and it is obtained by the regu- 

 lated action of fluorin on sulfur dioxid. The 

 conditions of the experiment had to be carefully 

 studied, as the reaction of these two gases is so 

 violent that explosions frequently occur. The new 

 gas is necessarily accompanied by others,. .because 

 the operation is carried on in glass vessels. The 

 separation of these gases is effected by liquefying 

 the whole at 80 C., and fractionating in a vacu- 

 um. Sulfuryl fluorid is a colorless, odorless 

 gas, solidifying in boiling oxygen, melting at 

 120 C., and boiling at 52 C. Although in 

 some respects it resembles its halogen homologue, 

 it recalls in its stability and inertness in other 

 reactions the properties of the hexafluorid. Thus 

 it is without action upon water, even in a sealed 

 tube at 150 C. M. Moissan remarks that these 

 experiments with fluorin show that although it 

 is undoubtedly at the head of the halogen group, 

 it is a little removed from the others, having spe- 



