38o 



KNOWLEDGE & SCIENTIFIC NEWS. 



[March, 1906. 



Auslralia, were apprehensive that Ceraiodus was likely 

 to become extinct, mainly owing' to their being largely 

 destroyed b\- settlers and miners, who highly esteemed 

 them as an article ol diet. 'I'hey were mostly killed 

 Ijy dynamite, a \ery destructive ag^ent. The curioui 

 lad was also noted that no small specimens of 

 Cciiili'iins were ever seen; two of those brought to vour 

 (iardens are the smallest 1 ever met with, excepting a 

 stuffed specimen, which measured 21 inches. The 

 Royal Society of Queensland, witli a view to the 

 preser\ation of Ccratodiis, resolved tO' remove specimens 

 to new iiabitals, and I was asked to undertake the 

 work. My first month's experience was verv dis- 

 couraging:, resulting in only one live fish, but better 

 success followed, and in less than six months, sixty- 

 nine examples were transported to six new- localitie,^. 

 This success encouraged me to try the experiment of 

 taking a few tO' England. I had some caught and kept 

 in captivity a few weeks, and fed mainly on prawns. 

 'I'iiey were shipped in the Duke of Devons/tirc, on the 

 15th of April, and arrived in, London on the 12th of 

 June, after a passage of eight weeks. My success was 

 mainly owing to the exceptionally fine weather cnjoved 

 t'aroughout the voyage, there not being an hour rough 

 between Brisbane and the Thames." 



Ceraiodus belongs to the " Dipnoan " (or double- 

 breathing) Order of Fishes — so called because they 

 breathe not only by their gills, as ordinary fishes, but 

 also by their lungs, like the higher vertebrates. 



Our picture (page 379), represents one of these 

 fishes coming up to the surface of the water, as thev 

 frequently do, to imbibe a little more oxygen. 



Besides Certitodns, there are two other fishes belong- 

 ing to the formerly widely-spread Order of Dipnoans, 

 the Lepidosvien of South America, and the Protopierus 

 of Africa. These three forms are the sole surv-ivors of 

 this great group, which in former ages was extensively 

 distributed over the earth's surface. 



Star Map No. 5. 



This map shows Orion in the right hand top corner, 

 Sirius cowards the centre, and the " False Cross " at the 

 bottom. Several fine stars are included in this region. 



ii Orionis (Uigel), magnitude 0-3. 



Nebula Orion M 42 (\' h. 30 m. f 30' S.), the great- 

 est nebula in the heavens. .Mthough only the nucleus is 

 readily visible, the nebula extends for vast distances all 

 around. Its spectrum shows it to be gaseous. 



e Ononis (V h. 22 m. 50° 28' S.). A multiple star in 

 the brightest part of the above nebula. Four stars of 

 6, 7, yl, and 8 magnitude form a trapezium. 



<T Ononis (V h. 34 m. 2^ 39 ' S.) " the hilt of the sword," 

 is a multiple star, consisting of 2 sets of treble stars, as 

 well as others. 



a Argus (Canopiis) (VI h. 21 m. 52^ 38' S.). The 

 second brightest star; magnitude- ro. 



a Canis Majoris [Sirius) [\l h. 41 m. id" 35' S.), 

 magnitude. -1-4. The brightest star in the heavens. It has 

 a. small companion, magnitude -g, at a distance of G'-^. The 

 light is calculated to be 30 times as bright as that of the 

 ■'?.""' "^^"fi'le the mass of the star is only 2h times as great. 

 Sirius is one of the nearest of the stars, the distance 

 being 8-6 light-years. Its parallax is -38. 



a Canis Minoris {Procyon) (\'1I h. 34 m. 5° 28' N.) is 

 another near and bright star. Its parallax is -3 ; distance 

 in light-years, lo-g. Magnitude, 0-5. It is accompanied 

 by a large and feebly luminous companion, giving out 

 only about one-thousandth the amount of the light of the 

 Sun. 



QviaclitaLtive Analysis 

 Without the Use of 

 Hydrogen Sulphide. 



By H. J. H. Ff.nton. 



1 HH sc])aration of metals belonging to the " second 

 g roup ' ' by means of hydrogen sulphide, in presence of 

 dilute hydrochloric acid, has hitherto been universally 

 regarded as one of the principal and essential stages in 

 systematic qualitative analysis. This method — origin- 

 ally de\ised by Bergmann and improved later by 

 Fresenius — may, of course, yield excellent results if due 

 precautions are taken; yet from a theoretical standpoint 

 it is anything but perfect, since the conditions (con- 

 centration, degree of " acidity," temperature, etc.), 

 which are favourable to the most complete precipita- 

 tion, vary considerably with the different sulphides. 



On the practical side the objections are more serious, 

 especially in view of the highly offensive and even 

 poisonous nature of the gas; there are difficulties also, 

 especially in small laboratories, in arranging for a 

 constant and regular supply, and considerable waste 

 invariably results owing to the excessi\e rate at which 

 the gas is passed and the inveterate tendency of 

 students to '" leave the tap turned on." 



In consequence of these objections many attempts 

 have from time to time been made to de\^ise methods of 

 separation which are independent of the use of hydrogen 

 sulphide. Klein, for example (1887), proposed the use 

 of ammonium dithiocarbamate, X'ogtherr (189S), of 

 ammonium dithiocarbonate; and Schiff and Tarugi 

 (1894), of thioacetic acid or its salts. Rawitsch (1899) 

 avoided the use of hydrogen sulphide itself by digesting 

 the mixture to be analysed with excess of yellow 

 ammonium sulphide, and subsequently treating both 

 residue and solution with dilute hydrochloric acid. 

 ,\one of these suggested modifications, all of which, it 

 will be observed, make use of sulphur compounds, have 

 received much support from chemists; either the pre- 

 paration of the reagent in question presents difficulties 

 or else the method of separating the resulting com- 

 pounds is found to be imperfect. 



A paper has recently been published by Ebler [Zeit- 

 schrift fur Anorganische Chemie, 1905 (48) bij, in 

 which he proposes to get over the above-mentioned 

 difficulties by entirely different methods and by employ- 

 ment, in some cases, of reagents which, although com- 

 paratively new, can now be easily obtained as com- 

 mercial articles. Possibly amongst our readers there 

 may be some who are interested in analytical chemistry, 

 but who have not the opportunity of studying the recent 

 literature on the subject, and to these a brief sketch of 

 the paper may be of advantage. 



In constructing this new scheme of analysis the 

 author takes advantage especially of the tendency 

 which certain metals have to form complex cations, of 

 various degrees of stability, with ammonia, and he 

 employs as reagents, in addition to those in common 

 use, s\ich compounds as hydniw lainine, hydrazine, 

 and potassium percarbonate. 



