In 1879 Penzoldt called attention to the extraordinary increase in respiratory activity following the administration of Aspidosperma quebracho-blanco. Wood and Hoyt1 have confirmed these observations, the amount of air breathed in some of their experiments being increased nearly 400 per cent. In this communication it was shown, however, that the drug was so active a depressant to the circulation as to preclude its utility as a clinical respiratory stimulant. With a view to determining whether the effects on the respiration and circulation might not be due to different alkaloids, so that one could be of value to practical medicine, I have recently undertaken the study of the individual alkaloids from quebracho furnished by Merck & Co.
There are contained in quebracho bark at least six alkaloids, namely: aspidospermin, aspidosamin, aspidospermatin, quebrachin, quebrachamin and hypoquebrachin. I have experimented with all of these except aspidospermatin and hypoquebrachin. The only one, however,