564 ANNUAL KECOKD OF SCIENCE AND INDUSTRY. 



as far as possible, ether spray was first made use of in re- 

 ducing the sensibility of the teeth ; a piece of cotton, dipped 

 in ether, and laid first on the teeth and then on the instru- 

 ment, being found to answer a still better purpose. While 

 engaged in this operation, it occurred to Mr. Napier to avoid 

 the usual practice of dentists (viz., of extirpating the nerve), 

 with which object he took a bit of hard wood, dipped it in 

 nitric acid, and with this cauterized the exposed portion of 

 the nerve in each tooth successively. He then filed the teeth 

 down to the level of the gums without producing any pain 

 whatever. He found that in this way the stump of the tooth 

 remained perfectly healthy, giving no pain of any kind; and 

 the subsequent experiences of the patients were of the most 

 satisfactory character. 20 A, December 5, 1874, 629. 



CAUSE OF DISCOMFORT IN TOBACCO-SMOKING. 



Quite recently Dr. Krause announced, to the dismay of 

 smokers, that a large amount of carbonic-oxide gas is gen- 

 erated in the process of smoking, and that the uncomfort- 

 able feelings experienced by beginners are due to the swal- 

 lowing of a portion of this. Dr. Vohl, however, disagrees 

 with this conclusion, and thinks that the effects in question 

 must be ascribed to the volatile organic bases which form 

 while tobacco is burning. 12 A, May 6, 1875, 15. 



PERNICIOUS ANAEMIA, A RECENTLY DEFINED DISEASE. 



The Medical Times and Gazette calls attention to the ex- 

 istence of a disease called pernicious anaemia, not previously 

 distinguished from the great mass of afflictions which man is 

 heir to ; referring at the same time to the gradual progress 

 in the accurate identification and definition of diseases, and 

 to the fact that it is but lately that such well-known affec- 

 tions as Bright's disease and Addison's disease have been 

 clearly appreciated. Pernicious anaemia, it seems, very often 

 follows chronic diarrhoea, and child-bearing appears to espe- 

 cially predispose to it. Those affected become extremely 

 pale, the skin of the hands, feet, and face acquiring a swollen 

 look. They become weak, and have attacks of giddiness and 

 palpitation of the heart, with failing appetite, and a feeling 

 of oppression in the epigastrium. Transient diarrhoea some- 

 times occurs, and feverishness without any attack of fever. 



