December 15, 1892] 



NA TV RE 



53 



of debt and difficulties. He struggled on, however, a 

 martyr to rheumatism and suffering from a complication 

 of internal disorders until he was struck down in the 

 spring of 1786. Some time before his fatal illness he had 

 formed the resolution of marrying the widow of his pre- 

 decessor so soon as his circumstances should permit : on 

 his death-bed he carried out this project, bequeathing to 

 his wife such property as he had been able to acquire. 

 Two days afterwards (May 21, 1786) he died at the age 

 of forty-four. 



The eleven years during which Scheele lived at Koping 

 were fruitful in investigations of the highest importance 

 in every department of chemistry. In that time he 

 discovered molybdic, tungstic, and arsenic acids 

 among, the inorganic acids ; and lactic, gallic, oxalic, 

 citric, malic, mucic, and uric among the organic acids. 

 He also discovered glycerin, determined the nature of 

 Prussian blue, and prepared hydrocyanic acid. He de- 

 monstrated that plumbago is nothing but carbon asso- 

 ciated with more or less iron, and that the black powder 

 left on the solution of cast-iron in mineral acids is essen- 

 tially the same substance. He determined the chemical 

 nature of sulphuretted hydrogen, discovered arseniureted 

 hydrogen, and invented new processes for preparing 

 ether, powder of algaroth, calomel, and magnesia alba. 

 He made numerous analyses of air by absorbing the 

 oxygen with a mixture of iron filings and sulphur. He 

 concluded that " our atmosphere contains always, though 

 with some little difference, the same quantity of pure or 

 fire air [oxygen] viz. -^.^ which is a very remarkable fact ; 

 and to assign the cause of it seems dif^cult, as a quantity 

 of pure air [oxygen] in supporting fire, daily enters into a 

 new union ; and n considerable quantity of it is likewise 

 corrupted or changed into aerial acid (carbon dioxide) as 

 well by plants as by respiration ; another fresh proof of 

 the great care of our Creator for all that lives." 



Scheele's greatest work, however, is unquestionably his 

 treatise on " Air and Fire," which appeared in 1777 with 

 a preface by Bergman, who, according to Thomson, 

 superintended its publication. This elaborate essay shows 

 Scheele at his best and at his worst ; it testifies to his genius 

 as an experimentalist and to his weakness as a theorist. 

 No one can read this, or indeed any other of Scheele's 

 memoirs, without being impressed by his extraordinary 

 insight, which at times amounted almost to divination, and 

 by the way in which he instinctively seizes on what is es- 

 sential and steers his way among the rocks and shoals of 

 contradictory or conflicting observations. No man was 

 ever more staunchly loyal to the facts of his experiments, 

 however strongly these might tell against an antecedent 

 or congenial hypothesis. Had Scheele possessed that 

 sense of quantitative accuracy which was the special 

 characteristic of his contemporary Cavendish, his work 

 on " Air and Fire " would inevitably have effected the 

 overthrow of phlogistonism long before the advent of 

 Lavoisier. His memoir is essentially an essay on oxygen, 

 of which he was an independent discoverer, in its rela- 

 tions to life and combustion. It is perhaps idle to 

 speculate on the causes which prevented his clear recog- 

 nition of the full truth. It may have been that he was 

 essentially a preparateur like Priestley, and that quanti- 

 tative chemistry had few attractions for him ; it is far 

 more probable that the character of his work was deter- 

 rnined by the circumstances of his position, by his poverty, 

 his lack of apparatus, and his want of assistance. As 

 it is, it remains one of the most remarkable circumstances 

 in the history of human knowledge that a man working 

 under such adverse conditions in a small village on the 

 shore of a Scandinavian lake should have been able to 

 change the entire aspect of a science. 



It was stated by Creil, the editor of the well-known 

 Netie Enldeckungen and Anna/en, in which many of 

 Scheele's papers first appeared, that the great Swedish 



NO. 1 207, VOL. 47] 



chemist was invited to this country with the offer of an 

 easier and more lucrative position than that which he 

 had * at Koping ; but that his partiality for Sweden and 

 his love of quiet and retirement delayed his acceptance 

 of the offer until a change in the English ministry 

 put a stop to the negotiations. Thomson, the author of 

 the "History of Chemistry" in mentioning this cir- 

 cumstance, expresses his doubts as to its truth, and 

 states that he made enquiries of Sir Joseph Banks, 

 Cavendish, and Kirwan, but none of them had ever 

 heard of such negotiation. Indeed the circumstance is 

 intrinsically improbable. " I am utterly at a loss,"" 

 says Thomson, " to conceive what one individual 

 in any of the ministries of George III. was either 

 acquainted with the science of chemistry or at all 

 interested in its progress. . . . What minister \n 

 Great Britian ever attempted to cherish the sciences, or 

 to reward those who cultivate them with success ? . . . 

 If any such project ever existed, it must have been an idea 

 which struck some man of science that such a proposal 

 to a man of Scheele's eminence would redound to the 

 credit of the country. But that such a project should 

 have been broached by a British ministry, or by any man' 

 of great political influence, is an opinion that no person 

 would adopt who has paid any attention to the history 

 of Great Britain since the Revolution to the present 

 time." T. E. Thorpe. 



WERNER VON SIEMENS. 



■pRNST WERNER SIEMENS was the eldest son 

 -*—' of Christian Ferdinand Siemens and Eleonore- 

 Deichmann ; he was born in .1816 at Lenthe in Hanover, 

 where his father was engaged in the business of agricul- 

 ture and forestry. 



From his very childhood the subject of this memoir 

 learnt the lessons of self-control and responsibility, for 

 owing to his mother's delicate health and his father's 

 occupations, the care of his younger brothers and sisters 

 devolved on himself and his sister Mathilde ; in these 

 younger days he also learnt tact, and his father taught 

 him that difificulties had to be faced and overcome, and' 

 that duties must never be avoided. 



In 1823, a few months after the birth of his brother 

 William (whose lamented death occurred here nine years 

 ago), the family removed to Menzendorf near Liibeck,. 

 in the Grand Duchy of Mecklenburg. In the Gym- 

 nasium of Liibeck Werner was educated up to his 

 eighteenth year, when, by the advice of his father — who 

 with rare prescience saw in Prussia the nucleus of German 

 Unity and Empire — he went to Magdeburg to volunteer 

 for service in the Prussian Army. For three years he 

 studied in the Military School of Berlin, and in 1838 

 received his commission as a lieutenant in the artillery, 

 and returned to Magdeburg ; he was soon transferred to 

 the Technical Division of the Artillery at Spandau,. 

 and afterwards to Berlin. 



In July, 1839, his mother died, and six months after- 

 wards his father ; and then, at only twenty-three years of 

 age, he became the veritable guardian of his younger 

 brothers and sisters. 



In 1842 he took out a patent in Prussia for electro- 

 plating and gilding, and having established a factory in 

 Berlin for putting his invention into practice, he urged 

 his brother William to devote his attention to the subject. 

 This the younger brother did ; and the story of his 

 enterprise and success in this country then and ever 

 since has been told by Dr. William Pole in his most 

 interesting biography of him ; to this volume and to the 

 works of Dr. \X^erner von Siemens, the first volume of a 

 translation of which has recently been published by Mr. 

 Murray, we are indebted for much of the information> 

 contained in this short notice. 



