402 



NA TURE 



[^UNE 2, 1910 



of the local attractions, but because a meeting in the 

 colonies has generally been followed by a large meet- 

 ing at home. Few places have industries the opera- 

 tions of which afford such interest to visitors. To 

 see an armour-plate rolled or the forging of some 

 huge mass of red-hot metal is a sight for a lifetime, 

 whilst the variety of the industries engaged in some 

 form of steel-making or silver-plating is very great. 

 Arrangements are being made whereby a large 

 number of the more important works will be open 

 for inspection by members. 



It is generally supposed that Sheffield is a sort of 

 city of dreadful night, and that it and smoke are 

 convertible terms. This is, however, a complete delu- 

 sion. Few cities of its size have more delightful 

 suburbs or such picturesque scenery in the neighbour- 

 hood. The city stands at the confluence of five 

 valleys, with contributory streams to the Don. The 

 ridges between rise sharply to 900 feet above it, and 

 then run up to the grouse moors, the valleys being 

 each distinctive and well wooded. The near neigh- 

 bourhood is full of historic and archaeological interest. 

 Sherwood Forest is on one side and Little John's 

 grave on the other. The Peak caverns, the beautiful 

 Derwent valley, with Chatsworth and Haddon and 

 the gorge of Matlock, are close at hand, and the 

 whole district is a pedestrian's paradise. It is hoped 

 no member of the association will be deterred from 

 coming by what he has seen from the railways, which 

 in many cases actually pass through some of the 

 large works. 



PROF. ROBERT KOCH, For.Mem.R.S. 

 T) Y the death of Prof. Robert Koch there goes from 

 -'-' amongst us one of the most remarkable men of 

 his time, a man of tremendous determination, great 

 capacity, and indefatigable energy, who has left an 

 impress on the science and practice of medicine such 

 as is made by a few exceptional men only. It would 

 be affectation to say that all his work is of equal value, 

 for although under his hand and mind no subject 

 could remain unaltered, his pioneer work on the 

 isolation and cultivation of bacteria in solid media, 

 his studies in anthrax, and his work on tuberculosis 

 and cholera, must always stand out above any other 

 that he did. The controversial methods of his earlier 

 years, as exemplified by his controversy with Pasteur 

 in 1883, were succeeded by methods of a less pungent, 

 but equally vigorous, character, but his arguments 

 were always respected, even by those who did not 

 agree with him, as those of a man thoroughly in 

 earnest, whilst his utterances could always be accepted 

 as those of a man who had every right, by reason both 

 of experiment and experience, to give full and free 

 expression to his opinions, opinions that must be care- 

 fully weighed and considered, especially by those who 

 differ most widely from him. 



Born in Klausthal, Hanover, on December 11, 

 1843, Robert Koch was a member of a large family. 

 His father held some official position in the Depart- 

 ment of Mines and Forests. At nineteen Koch com- 

 menced his medical studies in the University of 

 Gottingen, at which he worked for five years. After 

 passing his State examination and taking his degree, 

 he became assistant medical officer in the General 

 Hospital in Hamburg. He then engaged in private 

 practice, first at Langenhagen, near Hanover, mov- 

 ing thence to Rackwitz, where he remained until he 

 went as a volunteer surgeon with the army in the 

 Franco-Prussian war. In 1872 he again started pri- 

 vate practice, this time in WoUstein, in Posen, where 

 he commenced his investigations and studies on the 

 isolation of pure cultures of bacilli, studies which led 



NO. 2 I 18, VOL. 83] 



to the method of cultivation of bacteria on solidifying 

 media, a method to the use of which we owe many 

 of the most important advances made in the bacteri- 

 ology of disease. 



Up to Koch's time, Salomonsen's and Cohn's 

 methods of isolating single bacteria were the only 

 methods available. Salomonsen mixed a very small 

 number of organisms with a large quantity of blood, 

 and drew the mixture into a series of long, fine glass 

 tubes ; then as the organisms grew and used up the 

 oxygen in the blood, little black points made their 

 appearance along the course of the tube. Blood taken 

 from the tube broken at one of these black points was 

 often found to contain a pure culture of a single 

 organism only. This method, of course, could not 

 receive very general application, but as the blood 

 might coagulate in the tube, the organisms could not 

 move about at all readily until the clot was broken 

 down or decomposed by the organisms themselves. 

 Cohn's method consisted in diluting the culture con- 

 taining the organisms with very large quantities of 

 broth, and then taking a single drop and transferring 

 it to a flask or tube containing broth ; in this case 

 the observer trusted to the dilution being so great 

 that a single drop would contain only a single or- 

 ganism. These methods, imperfect as they were, were 

 used by Pasteur and Lister in their investigations, and 

 were brought by them to considerable efficiency. 



Koch's method of isolation was exceedingly ingeni- 

 ous but very simple. Taking a nutrient medium con- 

 taining meat juice or sugar along with certain saline 

 constituents to which had been added from 5 per cent, 

 to 10 per cent, of gelatin, he boiled or heated the 

 mixture several times to 70° C. or 80° C. in order 

 to destroy any germs that might already be present. 

 The material to be investigated was then added to 

 this sterilised nutrient medium whilst still in a f^uid 

 condition. The mixture was then well shaken, so as 

 to distribute any organisms that might be present, 

 and poured over a glass plate sterilised by heat con- 

 tained within glass vessels similarly sterilised. When 

 this nutrient medium cooled down it became a solid 

 jelly and the organisms were fixed in position, each 

 organism giving rise to a colony, so that each or- 

 ganism with its progeny was isolated and could be 

 studied separately. At this date we are apt to lose 

 sight of how much bacteriologists owe to Robert 

 Koch for this simple method, which was devised by 

 him in order that he might study more thoroughly 

 than had yet been done the anthrax bacillus, the 

 bacillus that gives rise to splenic apoplexy in cattle, 

 and to one form of malignant pustule in the human 

 being. By means of this method, too, he was able 

 to isolate and study various organisms found in 

 wound infection and in septicaemias of certain animals, 

 the results of which are given in a paper translated 

 and published in 1880 in the Transactions of the New 

 Sydenham Societ}-. His studies on the production of 

 immunity against anthrax in cattle and sheep were, 

 however, anticipated by Pasteur, who, in 1881, gave 

 his marvellous and striking demonstration at 

 Chartres. 



In 1880 Koch was appointed Government adviser 

 to the Imperial Board of Health, and in the labora- 

 tories in the Louisenstrasse carried out that series of 

 investigations which ended in the demonstration of 

 the presence of the tubercle bacillus in the diseased 

 tissues of tuberculous animals and in the sputum and 

 tissues of human beings suffering from tuberculosis. 

 Here again his ingenuity and mastery of methods 

 enabled him to do what so many others had failed 

 to accomplish — to stain the tubercle bacillus in the 

 tissues and to isolate and studv this organism on 

 artificial media outside the bodv. As the tubercle 



