492 



NATURE 



[September 22, 1892 



present more stable constellations.^ We do not doubt 

 that vital force is a mode of motion due to the presence 

 of atoms in labile positions in the albuminous substance. 

 The motion ceases when there occurs a migration of the 

 labile atoms to some stable position. The aldehydes 

 give us fine illustrations of labile combinations and stable 

 rearrangements in other allied substances. 



The question now arises, can we chemically demon- 

 strate that the albuminous substance formed by synthesis 

 in plants is — even before it has becojue protoplasm — 

 different from ordinary albumen? It was known long 

 ago that the juice of plants — that is the aqueous solution 

 in the vacuoles of the cells— contains albumen, but it was 

 thought to be ordinary albumen. It is easy to prove that 

 this is not the case." 



On treating living plant cells with dilute solutions of 

 ammonia or organic bases or their salts, remarkable 

 changes are observed. These consist either in the for- 

 mation of numerous minute granules as is the case on the 

 application of most of the bases, or in the production of 

 little globules flowing together to make relatively large 

 drops of a substance of high refractory power, as is the 

 case on the application of weak bases like caffein or anti- 

 pyrin.^ These latter two bases in weak solution do not 

 injuriously affect the protoplasm itself, since the cells will 

 keep alive for a number of days in a 0-5 per cent, solution 

 of these bases ; the cells are, however, soon killed by 

 other bases and their salts. The granules and globules 

 formed in the living cells by the action of caffein have 

 been called by Bokorny and myself Proteosomes. They 

 give the principal reactions of albuminous bodies, but 

 coritain in most cases an admixture of small quantities of 

 lecithin and tannin. These admixtures, however, can be 

 removed by cultivating the objects (the alga, Spirogyra, 

 for instance) in solutions rich in nitrates. If now by 

 such cultivation the tannin has been removed and the pro- 

 teosomes then produced by treatment with caffein, we can 

 observe that these albuminous proteosomes are capable 

 of reducing silver from even highly diluted alkaline solu- 

 tions. This property is lost after treatment with dilute 

 acids as well as after the death of the cells.* In these 

 cases the proteosomes become hollow and turbid, their 

 substance appearing to coagulate and shrink. 



There are thus experimental grounds for the conclusion 

 that not only the organized albumen of the living proto- 

 plasm, but also the albumen dissolved in the vacuoles — 

 the unorganized albumen— is a different substance from 

 the ordinary albumen, which is present in dead cells. 

 We may sum up the line of argument as follows :— 



I. Bases act upon the albumen of living cells ; not, 

 however, upon that of dead cells, nor upon ordinary dis- 

 solved albumen. 



II. The action may be observed microscopically to 

 take place in the case of various vegetable objects in the 

 liquid portion of the protoplasm itself as well as in the 

 vacuoles. This can be specially well observed with the 

 alga Spirogyra when treated with caffein. 



III. The granules and globules into which the active 

 albumen aggregates by the action of bases— called by us 

 proteosomes— have the property of reducing dilute silver 

 solutions in the absence of light, and lose this property 

 by the action of acids. 



IV. The active albumen in its most unchanged coxv- 

 dition can be made visible by caffein or antipyrin, two 

 bases that do not act as serious poisons to the cells. 

 Living cells containing proteosomes, brought out by caffein 



I JVIany examples can be cited from organic chemistry; for instance, the 

 rapid change of the diamidoaceton as [soon as it is liberated from its salts 

 (Berichte d. Deutschen Chem. Ges. 25, 1563). Compare also the article, 



Chemical Motions," Biolog. Centralblatt ix. N. 16. 



- O. Loew und Th. Bokorny, Biolog. Centralblatt xi. i. 



3 These globules closely resemble the aggregated masses that Darwin ob- 

 served after irritation of leaves of Drosera. 



f The proteosomes produced by ammonia and various other bases preserve 

 this property for a much longer time after the death of the cell than those 

 produced by caffein or antipyrin. 



NO. 1 195, VOL. 46] 



when placed in distilled water regain their original con- 

 dition, the proteosomes become gradually dissolved again 

 (rapidly at 25"C.), and a new application of caffein will now 

 make them reappear. 



V. If proteosomes are produced by caffein or antipyrin, 

 and the death of the cells is then caused by ether vapour,^ 

 &c , it may be easily observed that soon after the death 

 of the protoplasm the proteosomes of the vacuoles are 

 also changed in their optical and chemical properties ; 

 they become turbid and hollow, they coagulate, and 

 they lose their property of being resoluble in distilled 

 water. O. Loew. 



DISCOVERY OF A FIFTH SATELLITE TO 

 JUPITER. 

 TN January of the year 1610 Galileo, at Padua, ir^ 

 ■*• Italy, discovered four satellites revolving round 

 Jupiter, and though more than 282 years elapsed in the 

 interval, from that time to August, 1892, no additional 

 satellites were detected near this planet, and astrono- 

 mers naturally inferred that no others existed. The fact 

 that Jupiter possessed four satellites has become familiar 

 to every schoolboy, for it has been repeated in all the 

 astronomical text-books published during nearly three 

 centuries. Few people therefore could have imagined 

 that the statement would ever be controverted or ren- 

 dered untenable by new discoveries. In regard to the 

 more distant planets Uranus and Neptune, there was 

 every prospect of additional satellites being detected, 

 but with Jupiter the circumstances were somewhat differ- 

 ent. The four satellites were so bright and so palpably 

 visible in very small telescopes that it was scarcely 

 thought possible that another existed small enough to 

 remain unseen. Moreover, there was a significant agree- 

 ment in the relatively increasing numbers of the satel- 

 lites surrounding the planets Mars, Jupiter, and Saturn. 

 Mars was known to have two satellites, Jupiter four,^ 

 and Saturn eight, the number doubling itself with each 

 step outward from the sun, and it was considered pro- 

 bable that the harmony of the series would not be dis- 

 turbed. 



Now, however, the astronomical world has been ex- 

 cited by the announcement that a new satellite has been 

 discovered in attendance on Jupiter, and that its dis- 

 tance from the centre of the planet is 112,400 miles, and 

 its period of revolution 17 hours 36 minutes. The dis- 

 covery was effected by Prof, Barnard, of the Lick Obser- 

 vatory on Mount Hamilton in California, and, as he has 

 already proved himself a very acute observer, especially 

 of comets, and as he has the occasional use of what is 

 supposed to be the most powerful telescope hitherto 

 constructed, there is no good reason to discredit the in- 

 telligence. 



People will be obviously led to ask how this new satel- 

 lite managed to evade detection during nearly three 

 centuries of diligent telescopic research. How was it that 

 one at least of the host of observers who have studied 

 this plane and his circling moons by means of powerful 

 glasses, did not sight the tiny orb which has now revealed 

 itself to the watchful American astronomer .f" We imagine 

 that the chief reason for this want of success is to be 

 found in the fact that the new orb is not brighter than 

 the thirteenth magnitude, and that, being situated close 

 to its primary, it would therefore, in ordinary instruments, 

 be quite obliterated in the surrounding glare. But it is per- 

 haps rather singular that it was not detected by its 

 shadow, which would be projected on the disc of Jupiter 

 whenever the satellite passed between the planet and the 

 earth, and this would be of daily occurrence. At such a 

 time the shadow would appear as a small, black, circular 

 spot moving rapidly from east to west across the disc, 

 and with greater apparent velocity than the visible 



