May 27. 1887.J 



SCIENCE. 



515 



— Prof. W. G. Peck, LL D., is writing an 

 ' Analytical mechanics ' for the use of colleges 

 and scientific schools, embracing the course as 

 no5v taught at the School of mines, Columbia 

 college. Messrs. A. S. Barnes & Co. will pubhsh 

 it in the early summer. 



— Messrs. Ticknor & Co. announce for publica- 

 tion ' The Nigritians,' division 1 of ' The social 

 history of the races of mankind.' by A. Feather- 

 mann ; also ' The Melanesians,' division 2 of ' The 

 social history of the races of mankind,' by A. 

 Feathermann. These two learned volumes are 

 parts of the great group which was begun by the 

 publication of • The Aramaeans ' two years ago. 

 When all the volumes of ' The social history of 

 the races of mankind ' shall have been published, 

 the work will be found to be a comprehensive his- 

 tory of universal civilization, embracing not only 

 the civilized and most enlightened nations of the 

 earth that exist now, or had existed in the re- 

 motest ages, but treating equally of savage and 

 barbarous races, tribes, and nations, such as are 

 historically known to have existed in ancient 

 time, and such as exist now in Africa, Oceanica, 

 America, in the north of Europe, and in many 

 j)arts of Asia. 



LETTERS TO THE EDITOB. 



*^*The attention of scientific men is called to the advantages 

 of the correspondence columns of Science /or placing promptly 

 on record brief jjreliniinary notices of their investigations. 

 Tioenty copies of the number containing his communication 

 will be furnished free to any correspondent on request. 



The editor will be glad to piublish any queries consonant luith 

 the character of the journal. 



Correspondents are requested to be as brief as possible. The 

 writer^s natne is in all cases required as proof bf good faith. 



The cause of consumption. 



In regard to the so-called ' theory of consumption' 

 developed by Hamhleton, as described in a recent 

 number of Science (ix. No. 221), I think that our 

 knowledge of the cause of tuberculosis is now so 

 definite and precise that commvinications of that na- 

 ture are positively pernicious, if not made with more 

 discrimination, because they confound the cause of 

 the disease with the favoring or retarding influences 

 under which it may progress, and thus draw off at- 

 tention from one of the most important measures 

 which must be taken to guard against the contraction 

 and perpetuation of the disease. 



It is now definitely established that tuberculosis is 

 caused, and caused alone, by the presence and action 

 in the body of the bacillus tuberculosis. Tubercxx- 

 losis can no more appear in the body without the 

 previous entrance of the bacillus than a crop of corn 

 can spring up in the soil without the previous depo- 

 sition in some manner of the seed. And to gravely 

 discuss the probability of tuberculosis originating in 

 the body from any set of conditions not associated 

 with the bacillus tuberculosis is precisely analogous 

 with speculations as to the conditions of soil, climate. 



etc., which could cause a crop of corn to spring up 

 spontaneously in a field. 



As your correspondent ' Medicus ' points out, 

 Hambleton's array of facts affords strong confirma- 

 tory evidence of the infectious nature of the disease, 

 and shows the important influence on the develop- 

 ment and i^rogress of the disease of certain external 

 conditions of individuals and peoi^le. 



Before the discovery of the bacillus tuberculosis, 

 such hypotheses as Hambleton's were frequently 

 elaborated, and were useful as the best which could 

 be done at the moment. The facts upon which they 

 were based are still more useful to-day, but conclu- 

 sions from them should not be permitted to assume 

 a false relationship to the real causative agent in 

 tuberculosis. 



At present it does not seem probable that tubercu- 

 losis, when once definitely established in the body, 

 can be successfully combated by the administration 

 of drugs for the direct destruction of the bacilli, al- 

 though new methods of treatment based ujjon this 

 possibility are frequently suggested, and find one 

 after another a short-lived currency. It aj^pears 

 very doubtful whether the body can be sufficiently 

 saturated with any form of germicide to insure the 

 comi^lete destruction of the bacilli without destroy- 

 ing the life of the individual. 



But, on the other hand, much has been, and much 

 more may still be, done in the way of assisting the 

 cells of the body in their natural warfare against the 

 invaders ; as by the supply of suitable foods and the 

 furnishing of favorable hygienic and climatic con- 

 ditions. Heredity is, without doubt, an im23ortant 

 element in the origin and progress of the disease, 

 but it is unquestionably not a directly etiological but 

 only a secondary determining or accessory factor. 



When the public and the members of the medical 

 profession are sufficiently impressed with the over- 

 whelming importance of the primary infection of the 

 body with the bacillus tuberculosis — api^arently in 

 most cases from inhalation with dust of the bacillus 

 or its spores — in the causation and pei'petuation of 

 the disease, and are thereby led to urge and practise 

 the universal destruction or disinfection of sijutum 

 and all other discharges from tuberculous individ- 

 uals, we shall have taken the first stej) towards what 

 appears to be our only real and well-grounded hojae 

 of effectually stamping out the disease. The safe- 

 guards which we provide, or ought to provide, 

 against the invasion of Asiatic cholera, consist in 

 tlae destruction of the bacterium which causes it, 

 and although far more difficult of accomplishment, 

 owing to its constant and universal presence, this is 

 the task to which we must address ourselves in the 

 face of the far more important disease, tubercu- 

 losis. 



In the event of an invasion of Asiatic cholera, we 

 shoiild indeed consider and attempt to guard against 

 those conditions which seem to render an attack of 

 the disease more likely, such as digestive disturb- 

 ances, over-exertion, etc., and we should bring all 

 accumulated experience to bear upon the conduct of 

 the disease in the individual to a successful termina- 

 tion. But, after all, the main direction of our ef- 

 forts wotild lie in precautions against its spread, and 

 the speedy stami^ing-out of the disease by rigid 

 disinfection of all excretory material. In other 

 words, while the conduct of individual cases would 

 not be neglected, we should realize that in the wider 

 task of total eradication lay our chief duty. 



