ACTION OF ARSENIC 461 



the bladder) or pass a catheter and draw off all the urine 

 in the bladder. Test this for glucose, albumen and casts 

 (centrifuge and use the precipitate for microscopic observa- 

 tions). The injecting burette contains sodium arsenate so- 

 lution (one per cent). 



Draw off one cubic centimeter of blood from the femoral 

 artery and add to it one-half cubic centimeter of one per 

 cent copper sulphate solution. Draw off another cubic cen- 

 timeter of blood and add to it one-half cubic centimeter of 

 sodium arsenate solution (one per cent). Shake up both 

 tubes and observe them carefully. What conclusions can 

 you draw'? Of what immediate importance is this to you? 



When all adjustments are made take a normal, record 

 the time of day and inject one cubic centimeter of arsenic 

 solution. How are the blood-pressure and respiration af- 

 fected? Wait, a while and then inject another cubic centi- 

 meter. How does the reaction to this dose correspond with 

 that produced by the first dose? 



Continue the injections (small) slowly and allow the 

 drug to be fully distributed to all the tissues. The drug 

 should act for a long time (several hours) to produce the 

 most marked lesions. Keep the animal alive as long as you 

 can and from time to time inject as much of the arsenic as 

 the animal will tolerate. Obtain specimens of urine occa- 

 sionally and test for albumen and for reduction of Fehl ing's 

 solution. Do you detect any indications of an action on 

 the alimentary tract? How does the drug act here? What 

 renal structures are especially affected by the substance! 



Near the end of the exercise kill the animal with the 

 drug. Test the urine for albumen, glucose, and casts. Are 

 there any blood cells in the urine (centrifuge and put a 

 drop of the sediment on a slide, cover with a cover slip 

 and examine microscopically) ? Open the abdomen, pick 

 up the small intestine and incise it longitudinally. What 

 is the nature of the contents? Examine the mucosa care- 

 fully for congestion and hemorrhages. Save a piece of the 



