SCIENCE-GOSSir. 



2 43 



■ 0V'< . - 



CHEMISTlflll!] 



m 



CONDUCTED BY HAROLD M. HEAD, F.C.S. 



Arsenical Beer.— During the past month the 

 sensation-mongers of the daily newspapers have 

 had plenty of opportunity of indulging in a kind 

 of cheap criticism on the so-called "chemicals" in 

 beer. It would appear that some specimens of 

 glucose had become contaminated with arsenic 

 during manufacture from the starch which forms 

 its starting-point. How much or how little is 

 not known, for up to the present there has been 

 no authentic statement. It is so easy to remark 

 that glucose is " loaded with arsenic," and the 

 public would so much rather hear such a 

 remark than that the glucose contained 1 part of 

 arsenic in 25,000, which is really a high estimate, 

 that the newspapers naturally take the course 

 most palatable to their readers. Again, the 

 possibility of the presence of other substances 

 which would produce the symptoms of neuritis has 

 been entirely overlooked. Far be it from us to 

 try to minimise the extreme danger due to the 

 presence of any poison, vegetable or mineral, in 

 any article of food or clothing, but if we approach 

 the question with an open mind we cannot help 

 asking ourselves which patient is more to be 

 pitied, the one who is the victim of arsenic 

 poisoning, or the one who indulges in an excess of 

 the "pure" article? In considering the presence 

 of toxic substances in alimentary articles we may 

 ask how many of the large breweries and glucose 

 manufactories, not to mention hundreds of small 

 ones, employ a capable chemist ? A few do so, and 

 a few more employ a " consultant," who in the 

 pressure of other work cannot possibly be in a 

 position to devote himself to the careful study of 

 the one subject. When such an impurity as the 

 one we are discussing is by chance discovered, 

 there is a great outcry against the science in 

 general, while those who are least able to judge, 

 but yet are so placed that they can influence 

 public opinion, endeavour to particularise in a 

 manner which would make the tyro in chemistry 

 blush. It is with extreme interest that we await 

 the publication of authentic analyses and the cal- 

 culation of the amount of beer daily drunk before 

 the symptoms of neuritis supervene. 



Argon and its Companions. — In continuing 

 their work on the constituents of atmospheric air. 

 Professor Ramsay and Dr. Travers have found that 

 the gas to which they had provisionally given the 

 name of Metargon is not an element. The spec- 

 trum lines supposed to be characteristic were due 

 probably to the carbon monoxide and cyanogen 

 resulting from the presence of carbon in the impure 

 phosphorus they had used to remove oxygen from 

 the original air. Krypton, neon, and xenon have 

 now been obtained in sufficient quantity for the 

 determination of their physical constants. These 

 three elements with argon and helium appear to 

 form a characteristic group by themselves. They 

 exhibit gradations in such properties as refractive 



index, atomic volume, melting-point, and boiling- 

 point. While their periodicity is so marked, it is 

 curious that there is no place forthem in Men- 

 deleefE's Periodic Table. The grouping of the 

 elements which contain them appear a- follow-. :— 



I [ydrogen 



t 



Helium 



i 



Lithium 



Beryllium 

 9 



Fluorine 



IS 



Neon 

 20 



Sodi u in 

 23 



Magnesium 

 24 



Chlorine 

 35-5 



Argon 

 40 



Potassium 



39 



Calcium 

 40 



Bromine 

 80 



Ivrvpton 



82 



Rubidium 



85 



Strontium 

 87 



Iodine 

 127 



Xenon 

 128 



Caesium 

 133 



Barium 

 137 



The Past Century. — At the close of each 

 year it is a general custom for journals of science 

 to give their readers a brief history of the advances 

 made during the previous twelve months. The 

 practice is so universal that, in view of the many 

 advantages of such a course, it might be thought 

 pessimistic to point out a few of the defects. In 

 the present instance we are confronted, not with 

 the close of a year, but with the end of a century — 

 a century which has practically seen the birth of 

 organised science. If we were to endeavour to 

 give our readers a history, however brief, of the 

 chemistry of the nineteenth century, we should 

 require many pages of Science-Gossip before we 

 had emphasised even the main discoveries, without 

 touching upon the far-reaching effects and economic 

 improvements which have marked each step on- 

 wards. It is impossible to speak of a single branch 

 of any industry in which the influences of chemical 

 discoveries have not made themselves felt. In our 

 congratulations on the advances made we are, 

 however, saddened by the thought that our slowly 

 progressive nation still holds aloof from a genuine 

 scientific training for its youth, but prefers the 

 highly interesting, yet practically valueless stories 

 of the sacking of Troy and the loves of Dido. 



The Atomic Weight of Nitrogen.— The 

 classical researches of Stas having so long been 

 regarded as amongst the most exact work ever 

 accomplished in chemistry causes the paper read 

 by Dr. Alexander Scott on December 6th before 

 the Chemical Society to come as a surprise. Dr. 

 Scott finds that during a research having for its 

 chief aim the determination of the hydrogen to 

 oxygen ratio, by comparing the equivalents of 

 hydrazine, ammonia, and hydroxylamine, he could 

 not obtain the same equivalent as Stas for am- 

 monium bromide. The value given by the latter 

 is 98-032, while Dr. Scott rinds 97996, which would 

 lower the atomic weight of nitrogen from 14'046 

 to 11--010. a number much nearer that deduced 

 from the relative densities of oxygen and nitrogen 

 (16: 1 1-003). The silver used was prepared by the 

 reduction of silver nitrate by ammonium formate, 

 and its purity was tested in the severest way. Dr. 

 Scott considers that Stas's bromide must have 

 been contaminated by some impurity, probably 

 platinum, since it turned greyish at 11"> , the 

 colour increasing up to L80°, while his own am- 

 monium bromide could lie heated up to 1 so° with- 

 out change of colour, and could be sublimed in 

 ammonia vapour, the same results being obtained 

 before and after sublimation. 



