Chronic Lead Poisoning in Guinea Pigs. 49 



water. This free dye-acid has the following formula, 



with a molecular weight of 836. 



The dye-acid of iodo-eosin may be made by dissolving ten 

 grammes of iodo-eosin (commercial dye) in one per cent, potassium 

 hydroxide and then adding hydrochloric acid in excess. The dye- 

 acid is precipitated at once, it can then be filtered off and the 

 precipitate washed with hot water till the washings are acid-free. 

 The precipitate after drying is easily soluble in ether, forming 

 a beautiful yellow-colored solution. 



When this free dye-acid in ether solution is placed inside of an 

 intact rubber membrane immersed in ether, it can readily be noted 

 that in a few minutes diffusion currents are visible and the ether 

 outside of the bag becomes colored, showing that the free dye- 

 acid has diffused. 



The bearing of our results on the question of permeability and 

 impermeability of membranes will be considered later. 



Abstracts of the Communications, Pacific Coast Branch. 



First meeting. 



San Francisco, California, December 4, 1912. 

 36 (732) 



Chronic lead poisoning in guinea pigs. 

 By W. Ophuls. 



[From the Pathological Laboratory of Stanford University.) 



Of the twenty-eight guinea pigs treated with sublethal doses of 

 carbonate of lead seven (25 per cent.) showed a peculiar condition 

 to which so far attention does not seem to have been directed. 

 There has developed a hemorrhagic, sero-fibrinous inflammation 

 of the pericardium, of the peritoneum in the upper part of the 

 peritoneal cavity and occasionally also of the pleurae. In the 

 pericardium the lesion commences with a hemorrhagic exudate 

 followed by the formation of fibrinous deposits especially on the 

 parietal layer and ending with organization with marked thicken- 



