1876.] 
Papyrus Ebers . 
95 
some chemical relation between the oocyans and bile. Bili- 
rubin can indeed easily be converted by oxidisation into a 
blue substance ; but this differs entirely from either of the 
oocyans, both in its spectrum and in the character of the 
products of its decomposition. The residual bile-produFt 
found in faeces is in all probability a representative of a 
much further stage of change than to the oocyans ; and if it 
could give rise to them it would be by a process of integration, 
which is not at all likely. On the whole their connection 
with bile is as if we had two parallel series of products de- 
pending on two distinct physiological processes — one in the 
liver giving bile, and the other in the oviduct giving rise to 
egg-shell pigments. 
The application of the various methods and general 
principles described in this paper furnishes us with a very 
wide field for inquiry. It may safely be said that scarcely 
anything is yet known compared with what remains to be 
learned. The very foundations of the science require to be 
laid, and the full significance of the various facts determined, 
since optical facts have outstripped chemical knowledge. 
I however trust that the general outline I have given of this 
particular branch of inquiry will serve to indicate what kind 
of results we may hope to obtain, and to show that such 
investigations may throw an unexpected light on many inte- 
resting biological problems. 
VI. THE EARLIEST MEDICAL WORK EXTANT. 
By H. Carrington Bolton, Ph.D., 
School of Mines, Columbia College, New York. 
EFERRING to my “ Outlines of a Bibliography of 
the History of Chemistry,”* Mr. G. F. Rodwell, 
author of “ The Birth of Chemistry,” has expressed 
the hope that in the progress of Egyptian discovery valuable 
information in regard to the history of chemistry may be 
brought to light. This hope has been in some measure 
realised by the appearance of a fac-simile of an Egyptian 
medical treatise written in the 16th century b.c., which 
when fully deciphered will undoubtedly prove of immense 
value to the historian and to the student of science. Though 
strictly a medical work, it reveals much relating to ancient 
* “ The Chemical News,” vol. xxxii., pp. 36, 56, 68. 
