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the disease. He approaches the subject from the standpoint of the experimental 

 pathologist. The principal object of the author has been to bring together into a 

 convenient form suitable for ready reference an account of the most important 

 researches relating to the aetiology of tuberculosis, and particularly of the investi- 

 gations carried out by the late Royal Commission of Tuberculosis, the Reports 

 issued by the Local Government Board of England and Wales, and the records of 

 the Department of Health of the City of New York and the Imperial Board 

 of Health in Berlin. The work opens with a statement summarising the heavy 

 tribute exacted by tuberculosis, and this is followed by a consideration of factors 

 which have been influential in the past in securing a decline in the prevalence of 

 the disease. The major portion of the volume is devoted to an able exposition 

 of available knowledge respecting the tubercle bacillus and its various varieties or 

 " Types." Particulars are provided regarding distribution, cultural characteristics, 

 comparative virulence, and special attention is directed to the sharpness of 

 characterisation of these types and their stability under conditions which might 

 be supposed to conduce to modifications. These considerations, instead of being 

 viewed as merely of academic interest, are really of immense importance in the 

 conduct of a scientifically directed campaign for the arrest and eradication of 

 tuberculosis. 



While Dr. Cobbett's book will doubtless appeal mainly to members of the 

 medical profession, it is so lucidly written in crisp, direct, unambiguous words, 

 and as far as possible in non-technical form, that it can be read with profit by all 

 thoughtful men and women. Difficulties, ignorances, controversies are all fully 

 faced and dealt with fairly and in detail ; but the author does not hesitate to 

 express doubts or formulate opinions. He deals, in particular, with the part played 

 by personal contagion, the relative importances of individual predisposition, 

 opportunities for infection, influence of quantity of dosage of effective tubercle 

 bacilli, channels and portals of entry, and the like. The question of tuberculosis 

 in animals receives lengthy consideration, and the difference in response to 

 invasion by tubercle bacilli presented by different species is pointed out, special 

 attention being directed to the types of bacilli found in instances of naturally- 

 acquired tuberculosis in each animal species and in the relative susceptibility of 

 that species to infection with each of the three types as shown by artificial experi- 

 ment. It is interesting to note that it is not always the type which is most virulent 

 for a given species which is responsible for the majority of instances in it of 

 naturally acquired disease. The descriptions of the lesions and types of tubercle 

 bacilli found in human tuberculosis are very full and of far-reaching practical 

 importance. It is interesting to find the following opinion expressed in regard to 

 the relative importance of human and bovine infection in so-called " surgical " 

 forms of tuberculosis : " Bone and joint tuberculosis appears in most countries to 

 be due largely to tubercle bacilli of human type. The contribution made by 

 infection from a bovine source would appear from the evidence available, which is 

 admittedly somewhat meagre, to be on an average in various countries, excluding 

 Scotland, small. In Edinburgh and neighbourhood a very large share has been 

 claimed for bovine infection, amounting roughly to 60 per cent, of the cases in 

 children. This claim needs confirmation. It seems to us unlikely that there 

 should be so great a difference between Edinburgh and other great cities. 

 Possibly some ' pocket ' of bovine infection has been tapped. Nevertheless, a 

 substantial case has been made out both in the case of tuberculosis of bones and 

 joints, and in that of cervical glands, for the view that the relative proportion of 

 infections with tubercle bacilli of bovine and human type differs considerably in 



