G. GENERAL NATURAL HISTORY AND ZOOLOGY. 16 V 

 COMPOSITION OF THE BONES IN PARALYTICS. 



During an investigation of the composition of the rib- 

 bones of general paraly tics by Mr. Brown, the conclusion was 

 reached that the ratio of organic constituents to earthy mat- 

 ter is much greater, and the ratio of lime to phosphoric acid 

 distinctly less, in them than in the ribs of healthy adults, 

 these being; the same differences that exist between the com- 

 position of adult large bones and those of the fetus. Whether 

 this peculiarity in the ribs of paralytics is due to arrest of 

 development or to a degeneration of the fully developed bone 

 the author does not feel able to decide at present, but he is 

 under the impression that both causes will be found to op- 

 erate. The result of the experiments he considers rather as 

 suggestive than conclusive, it being unsafe to generalize from 

 so few examples. He therefore advises farther research on 

 the subject, with the hope of arriving at some definite and 

 final conclusion. 



INFLUENCE OF CLIMATE ON ANIMAL ECONOMY. 



In the proceedings of the Royal Society of London will be 

 found a paper by Dr. Rattray upon some of the more impor- 

 tant physiological changes induced in the human economy 

 by a change of climate, as from temperate to tropical and the 

 reverse, the inquiries being directed toward the peculiarities 

 of respiration, the pulse, temperature of the body, kidneys 

 and skin, and weight and strength. In regard to the subject 

 of respiration, the author shows, as the result of many experi- 

 ments, that in the tropics there is an increase in the capacity 

 of the chest for air, with a decrease of the number of respira- 

 tions, from which it results that the lungs, unaltered in size, 

 contain less blood and more air in tropical than in temperate 

 climates, the blood being in part diverted to the excited skin 

 and liver. The benefit derived in the early stage of con- 

 sumption by a sojourn in a tropical climate he explains in 

 the following manner : " Residence in a warm atmosphere is 

 followed by a decrease in the quantity of blood in the affect- 

 ed lungs, by diminished activity in the vital processes car- 

 ried on therein, by facilitated respiration, and, above all, by 

 diminished lung-work from vicarious action of the physiolog- 

 ically excited skin and liver; while the inhalations of milder, 



