NO. 23 INFLUENCE OF ATMOSPHERE ON HEALTH 4I 



and D'Arsonval, but of Rosenau and Amoss, for the surviving guinea- 

 pigs were not sensitized in the slightest degree to an intracardial injec- 

 tion of 0.5 cc. of rat's serum. Subsequent intravenous injection, how- 

 ever, with o. 1 cc. of rat's serum killed the animals with all the char- 

 acteristic anaphylactic symptoms. 



The animals, especially the rats, did not gain weight so well in 

 the second week as in the first ; there was evidently some deleterious 

 influence at work. To determine this we first tried the effect of 

 partially drying the air. We took two boxes of equal size, but with 

 the same number of rats and guinea-pigs in each, and arranged the 

 same degree of ventilation. In one box we placed just above the 

 animals large trays of granular calcium chloride, and in the other, 

 as a control, trays of broken pumice. The temperatures wet and dry 

 were taken, as well as the percentage of C0 2 . The animals were 

 fed and the boxes were cleaned daily. As the temperature did not 

 exceed 22.5 ° C. and generally was below 20 C, it was not likely 

 that the drying of the air and lowering the wet bulb by 2° to 3 C. 

 would make any difference in the rate of growth ; and it did not. 



Ten of these guinea-pigs, after living with rats for 14 weeks, re- 

 ceived injections of rat's serum into the veins of the ear. None of 

 them showed any symptoms of anaphylaxis. 1 



We next tried the effect of substituting for the wooden lid of 

 each box one made of glass, so submitting the animals to the stimu- 

 lus of light and a view of the outside world, in place of dim obscurity. 

 Periods of light and dark alternated. The growth of the animals 

 appears accelerated by light and retarded by dark. The light and 

 the sight of the surrounding world stimulates activity, and so the 

 metabolism and growth. The experiment demonstrates in terms of 



1 Four of these guinea-pigs later received an intravenous injection of 0.1 cc. 

 by the ear and were all killed by anaphylactic shock. Two of the others were 

 injected intraperitoneally with 5 cc. of water condensed on a piece of glass 

 covering a box containing 12 rats. This injection caused no ill effects. We 

 have since pursued this line of research further. In all, including the above- 

 mentioned two, twelve guinea-pigs have been injected intraperitoneally with 

 doses varying, according to the size of the animal, from 3-5 cc. of conden- 

 sation water. Subsequent intravenous injection a month later with 0.2-0.3 cc - 

 of rat's serum has in no case caused any anaphylactic symptoms. A further 

 intravenous injection of 0.2-0.3 cc. rat's serum has evoked marked anaphylactic 

 symptoms resulting in death in all but one case, which however suffered 

 severely and subsequently recovered. One of the young born after the first 

 injection of rat's serum into the mother was killed by an intravenous injection 

 of 0.1 cc. of rat's serum. (Foot-note added in proof, May, 1913.) 



