558 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



ure has been left at rest, a renewed development is produced 

 by stirring the fluid. 



As the result of such experiments as this and others, we 

 are informed that good glycerine should be colorless, of a 

 pure, sweet taste, completely fluid, and miscible in any pro- 

 portion with water or spirit of wine. Turbidity, or a gelati- 

 nous separation, induced by the addition of strong spirit of 

 wine, indicates the presence of gum. Concentrated sulphur- 

 ic acid should not induce a brown color or the development 

 of gas ; and further addition of spirit of wine should be fol- 

 lowed by no turbidity nor deposit indicative of the presence 

 of chalk or lead. No brown discoloration should ensue on 

 heating in a solution of potash, nor should any smell of am- 

 monia be perceptible. 



In mixing lymph an equal portion of distilled water is to 

 be added ; but when the lymph is to be preserved for a long 

 period, it may be mixed with undiluted glycerine, as this will 

 probably preserve it longer from decomposition, and the water 

 may be added when the lymph is to be employed in practice. 

 20 A, October 21, 1871, 504. 



LOMBARD OX THE CLIMATE OF MOUNTAINS. 



Dr. Lombard, in studying the climate of mountains, espe- 

 cially in Switzerland, has directed especial attention to the 

 effect which such a climate exercises upon pulmonary dis- 

 ease ; and he comes to the conclusion that an abode at a 

 considerable altitude prevents the development of consump- 

 tion, and may even cure it, either by developing the pulmo- 

 nary emphysema, or in favoring the functional peripheral ac- 

 tivity. 31em. Soc. Physique de Geneve, XXL, 1870, 375. 



WEAKENING OF FATAL MALADIES. 



According to M. Alphonse de Candolle, when a fatal mal- 

 ady has seriously affected the younger portion of a popula- 

 tion, the succeeding generation, descended from persons who 

 escaped the disease or were but little affected by it, will be 

 found less liable to its attack, as an ordinary effect of the law 

 of descent, this continuing to be the case from generation 

 to generation. This, therefore, constitutes one cause of the 

 weakening of epidemics, and may serve to explain the reason 

 why a disease is most injurious when it first attacks any 



