256 



SCIENCE. 



[N. S. Vol. IX. No. 216. 



kills the bacilli and their spores with incredi- 

 ble rapidity. The dryness and cold also work 

 against the existence of microbes. 



But how can the rarefied air influence favor- 

 ably pulmonary tuberculosis ? After prolonged 

 experimental study our authors sum up their 

 results in certain theorems, which are discussed 

 separately: (I.) Lessening pressure increases the 

 circulation of air in the lungs, dilates them and 

 obliges torpid parts to functionize. (II.) Lessen- 

 ing pressure determines a greater quantity of 

 blood to the lungs. (HI.) Lessening pressure, 

 dilating the lungs, permits a uniform distribu- 

 tion of blood, makes regular its circulation and 

 thus combats congestion. (IV.) Lessening pres- 

 sure diminishes intrapulmouary tension in gen- 

 eral and in particular intravascular tension. 

 (V.) Augumentation of red globules and white 

 globules. (VI.) Desiccation of mucous surfaces. 

 The favoring of evaporation. 



Numerous experiments on animals were fol- 

 lowed by the actual treatment of tuberculosis 

 by rarefied air, diminution of pressure. The 

 results were highly encouraging and remark- 

 able. Of the 13 healthy persons and numerous 

 consumptives submitted to the action of rarefied 

 air not one experienced the alarming symp- 

 toms described by P. Bert (Pression baromet- 

 rique, p. 750). The experiments of Paul Bert 

 having been credited, put a stop to all progress 

 in these matters, and the whole world is in- 

 debted to Herrera and Lope for removing the 

 embargo and smashing the tabu. 



Of 13 cases of pulmonary tuberculosis treated 

 by baths of rarefied air only one lost weight, 

 one remained stationary, eleven increased most 

 notably in weight, one increasing 300 gr. each 

 day, one increasing 28 gr. each day during 4 

 months of treatment. 



Our authors hold that the acclimation of 

 plants, animals and man to the atmospheric con- 

 ditions of high altitudes is rapid and in general 

 perfect, without the slightest loss of vigor. 



The vegetable kingdom reaches its maximum 

 at high altitudes. As for mere size we need 

 only mention the great tree of Tula and the 

 tree of Montezuma. Any limitation is question 

 of temperature, not atmospheric density. Spe- 

 cies ascend the summits as they approach the 

 equator. This is a pregnant hint for scientific 



agriculture. The more intense light of the alti- 

 tudes, as also the dryness and decreased pres- 

 sure, influence favorably the formation of chloro- 

 phyl, the decomposition of carbonic acid, the 

 formation of amidon, the movement of proto- 

 plasm, the multiplication of epidermic cells, the 

 force of transpiration, the absorption of oxygen. 



As for animals, the fact that many species 

 emigrate periodically to high altitudes and 

 flourish there proves that often acclimation is 

 exceedingly quick. Mammals are subject to 

 ' mal des montagnes ' and then must undergo a 

 period of acclimation more or less troublesome- 

 The symptoms are analogous to those in man. 

 But the result is perfect adaptation. Longevity 

 is not decreased, nor fecundity, nor secretions 

 («. g. milk). 



In the blood the number of red globules aug- 

 ments with the altitude. There is an exact 

 proportion between this number and the baro- 

 metric pressure of the locality. This is so little 

 known that in Mexico reputable physicians 

 have declared patients not sufiering from 

 anemia despite most evident symptons, simply 

 because microscopic examination of the blood 

 disclosed the number of the globules considered 

 as normal in Europe ! The tension of the blood 

 diminishes with the altitude. On the other 

 hand, the intensity of intra-organic combustion, 

 the temperature, the colorification is exactly 

 the same for inhabitants of the City of Mexico, 

 at an elevation of 7,350 feet, as for man at the 

 low European levels. 



This whole book is so unexpectedly rich in 

 scientific contributions of the most momentous 

 practical importance that no one working in 

 any of the subjects touched can afl!brd to be 

 without it, and our sister republic deserves to 

 be publicly congratulated on its appearance. 

 George Betjce Halsted. 



Austin, Texas. 



books received. 

 A History of Physics. Floeian Cajoei. New York 



and London, The Macmillan Company. 1899. Pp. 



viii + 322. $1.60. 

 The Microscopy of Drinking Water. Geoege Chand- 



LEE Whipple. New York, John Wiley & Sons ; 



London, Chapman & Hall, Ltd. 1899. Pp. xii ■{- 



300 and 19 plates. 



