750 POPULAR SCIENCE MONTHLY. 



mentioned being diseases of lower animals which may be trans- 

 mitted to man. And in tuberculosis and glanders affecting do- 

 mestic animals we have still another method of establishing the 

 diagnosis in suspected cases. This is by the subcutaneous injec- 

 tion of a proper dose of a filtered culture of the specific patho- 

 genic bacteria. These filtered cultures, containing the soluble 

 toxic products developed during the growth of the bacillus, are 

 known in the one case (tubercle bacillus) as tuberculin, and in 

 the other (glanders bacillus) as mallein. The effect is similar in 

 each case. When an animal infected with tuberculosis receives a 

 suitable dose of tuberculin a characteristic febrile reaction is pro- 

 duced. In the non-infected animal this reaction does not occur. 

 The same is true as regards animals infected with glanders which 

 receive a dose of mallein. This test of infection is now exten- 

 sively used both in this country and in Europe with very satis- 

 factory results. The importance of an early recognition of these 

 chronic infectious diseases is apparent. The danger from infected 

 animals is not limited to the extension of the disease to others of 

 the same species, but in tuberculosis those who consume the milk 

 are exposed to the danger of infection, especially in cases where 

 the udder of the animal is the seat of a tubercular infection. 



I have by no means exhausted my subject, and an attempt to 

 do so would probably exhaust the patience of my audience. In 

 conclusion, I would say that the painstaking laboratory work 

 which has led to the important practical results referred to is 

 still being prosecuted with unabated vigor, and without doubt 

 we may look for further valuable additions to our knowledge. 

 These, together with a wider appreciation of the present status of 

 this department of scientific investigation, can not fail to add 

 largely to the practical results which will hereafter be achieved 

 in the field of preventive medicine and of specific therapeutics, 

 and in agriculture, in the dairy, etc., as heretofore indicated. 



THE Prince of Monaco recently reported to the French Academy of Sci- 

 ences on the results of his deep-sea dredging- expedition of 1895, from Port- 

 ugal to the Azores and back to the English Channel. The dredgings were 

 carried to the depth of forty-two hundred metres, where weirs were depos- 

 ited ; and numerous soundings were made, some of them as far down as 

 five thousand metres, and specimens of the water drawn up. Fine captures 

 were made in the weirs from fifteen hundred metres, in which echinoderms, 

 mollusks, and fishes were plentiful. Thus, three hundred and fifty-five 

 animals were taken in twenty-four hours in the same net three hundred 

 of them fishes, large red shrimps, and cephalopods. Besides the usual 

 fauna of such profundities, crayfishes eighty centimetres long and superb 

 holothurias of forty-six centimetres were drawn up from the depth of four 

 thousand metres. 



