386 



NATURE 



[December 5, 191: 



and it is inferred tfiat the head ought to merge 

 more gradually into the main body of the member 

 than is at present the common practice. The 

 appUcations of optical science may possibly be of 

 use, therefore, in the design of structures and 

 machines, as these examples indicate, especially 

 where new problems arise, such as in the design 

 and construction of aeroplane stays and struts. 



>tandard types of eye-bars used 



where a poorly designed member adds weight 

 without coresponding strength, and may by its 

 failure result in a serious loss of life. 



E. G. COKER. 



THE WARFARE AGAINST TUBERCU- 

 LOSIS. 

 PROF. METCHNIKOFF delivered the Lady 

 Priestley Memorial Lecture for 1912-13 

 under the auspices of the National Health Society 

 at the RoN-al Society of Medicine on November 29. 

 Sir Crichton Browne presided, and among others 

 present were Sir Thomas Barlow, President of 

 the Royal College of Physicians. Sir Rickman 

 Oodlee,' President of the Royal College of Sur- 

 geons, Sir Ray Lankester, Sir James Goodhart, 

 Sir .\lmroth Wright, Sir Lauder Brunton, Dr. 

 and Mrs. Priestley, Sir Edward and Lady Busk, 

 and Mr. and Mrs. Stephen Paget. 



The subject of the lecture was the campaign 

 against tuberculosis, and subjoined is a summary 

 of Prof. Metchnikoff's remarks. 



Although tuberculosis had been regarded by 

 some as" contagious, particularly in southern 

 countries, it was a French observer, \'illemin, who 

 NO. 2249, VOL. 90] 



fifty years ago showed that the disease can be 

 transmitted by inoculation. Then in 1881 Robert 

 Koch discovered the causative germ, the tubercle 

 bacillus. Several species, or at least strains, of 

 the tubercle bacillus are known, and piscian, 

 a\'ian, and mammalian forms are now recognised, 

 ;ind the bacilli of man and of bovine animals also 

 exhibit differences, but the variety peculiar to man 

 is the great source of human 

 tuberculosis. 



Tuberculosis is a common dis- 

 ease, but does not kill rapidly, 

 and may take months or even 

 years before ending fatally. The 

 bacillus causes the formation in 

 the tissues of cellular nodules, 

 the tubercles, in which large 

 multi-nucleated cells, the "giant " 

 cells, are present, and perform a 

 defensive function, ingesting and 

 destroying tubercle bacilli, so that 

 in favourable cases the nodules 

 heal and disappear, or become 

 fibrous or calcareous and inert. 



There is evidence that tubercu- 

 lous infection is exceedingly fre- 

 quent, for the healed or calcareous 

 tubercles are very common at the 

 apex of the lung of those dying 

 from any cause, and can also be 

 demonstrated by applying the 

 Pirquet test. this consists in 

 applying tuberculin to a scarified 

 patch on the skin, which gives 

 rise in tuberculous persons to an 

 inflamed red spot, and 90 per 

 cent, of the adult European popu- 

 lation is shown in this way to 

 have been infected with the tubercle bacillus, 

 yet only 15 per cent, die of tuberculosis. Among 

 the Kaimuk Tartars, studied by Prof. Metchni- 

 koff, however, tuberculosis is rare, but this_^ is not 

 due' to a natural insusceptibility, for Kaimuk 

 youths residing in towns in Russia tor purposes 

 of education contract tuberculosis freely. 



.Attempts to cure tuberculosis by drugs, diet, 

 climate, serum, and tuberculin were discussed, 

 but the conclusion was expressed that, though 

 some of these are helpful, no real remedy or sure 

 treatment for tuberculosis has been found. 

 Nevertheless, the death-rate from tuberculosis in 

 large cities, such as London, Hamburg, and 

 Copenhagen, is steadilv declining, and this result 

 Prof. Metchnikoff ascribes to unconscious inocu- 

 lation by infection with mild or benign strains of 

 the tubercle bacillus, which serves to protect 

 against the virulent organism. It is on these 

 lines that Prof. Metchnikoff believes that the 

 stamping out of tuberculosis is to be attempted, 

 viz., the discovery or artificial production of strains 

 of the tubercle bacillus having but slight viru- 

 lence, which, on inoculation in suitable doses, will 

 serve to protect the inoculated agrainst the viru- 

 lent organism. R- !• "• 



