34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 60 



pens, droplets may be carried on from the farther side of the wool into 

 the condensation water. Breathing through a tube leads to an expul- 

 sion of saliva which does not occur in natural breathing. Dust of 

 white lead may be carried through four wash bottles by a current of 

 air. 1 



The guinea-pigs, as we might expect, therefore became sensitized 

 to human protein by the injection of the condensation water contain- 

 ing traces of salivary protein. 



Rosenau and Amoss do not take this view, and think that their 

 results afford evidence in favor of the exhalation of a volatile protein 

 — an organic chemical poison. They say they " have always felt 

 that a vitiated air must contain substances which are harmful, even 

 though not demonstrable to science," and suggest that the sensitivity 

 of some adults to a first injection of horse serum may be due to 

 such adults having worked with horses and breathed their breath. 

 Horse dung and horse hairs seem to us far more likely to produce 

 anaphylactic sensitivity in a groom than the breath of ten thousand 

 horses. The authors say " there is a growing tendency to regard 

 the ill effects of vitiated air as due to increased temperature and 

 moisture ; it is now apparent that there are other factors which must 

 be taken into account." But the question is — Do men breathe out a 

 substance poisonous to man? If there were anything in these claims, 

 we should expect to find guinea-pigs which dwell in the same con- 

 fined cage, and breathe each other's breath, sensitive to the injection 

 of a trace of each other's protein. All those who study the phenom- 

 ena of anaphylaxis know that no such sensitivity can be shown. 

 Anaphylaxis can be produced only by the injection of a foreign 

 protein. No one has ever demonstrated that it is possible to pro- 

 duce anaphylactic sensitivity by the assimilation of protein from the 

 alimentary tract ; in fact all the evidence of daily experience is 

 against such a possibility. There is no more likelihood that a foreign 

 protein should have such an effect when absorbed from the respira- 

 tory tract. We (M. F. and L. H.) have put the matter to the test, 

 and in this part of the research Dr. James Mcintosh cooperated 

 with us. The method we have adopted is one which places the 

 animals in a condition similar to that of men living in a crowded, 

 confined atmosphere. Rats and guinea-pigs lived together at the 

 bottom of boxes, the lids of which were only so far opened as to 

 give imperfect ventilation. Thus, the animals lived in obscurity, 

 and in an atmosphere containing 0.5 to 1.5 per cent CO.,. The 



1 Legge and Goadly : Lead Poisoning; Arnold, 1912. 





