1912.] Relation betiveen Capillary Pressure and Secretion. 443 



with ether, we have obtained readings much exceeding these figures — 

 45-65 mm. Hg (Tables I and II). With chloroform as the anaesthetic, 

 especially in deep anaesthesia with low blood pressures, we have obtained in 

 some cases readings approximating more closely to those of other observers. 

 This has also been the case when any leakage of aqueous has occurred. 

 After such leakage the intraocular pressure may measure 20-30 mm. Hg, 

 and the eye then feels to the finger much less tense than does the other 

 normal eye. 



Table II. 





Normal inti';n n-nlar 



On squeezing 



On stopping 







pressure with L.H. 



the belly. 









needle. 



Eise. 



Fall. 







cm. H 2 0. 



mm. Hg. 





TT O 





Chloroform . . . 







~7 







28 



21 



121 



12 







73 



54 -4 







80 cm. H 2 on very light 













anaesthesia. 





38 



28 -3 









A.C.E 



73 



54 -4 



= 



= 



Reading 70 cm. H 2 after 













1 hour. 



Ether 



76 



56-7 



12 



22 



B.P. 118 mm. Hg. 





60 



45 



12 



20 



B.P. 110 mm. Hg. 





87 



65 



13 



60 



B.P. 190 mm. Hg. On 













pithing medulla, B.P. fell 













quickly to 44 mm. Hg, 













eye to 54 cm. H 2 = 





84 



62 -7 







40 mm. Hg. 





68 



50 -7 









Chloroform . . . 



22 



16 -4 







Animal deeply under, leak. 





43 



32 





21 



By anaesthetising deeply 













went to 29 cm. H 2 0, on 













light anesthesia rose to 













66 cm. H 2 0. 





36 



27 







On deep anaesthesia fell to 













26 cm. H 2 0. 



Ether 



55 



41 









68 



50 -7 



10 



26 







72 



53 -7 



6 



13 







84 



62 -7 



8 









66 





12 







Since the intraocular pressure is raised by traction or by pressure on the 

 eyeball, it is necessary to support the needle. We always hold the needle 

 in such a way as to give the lowest readings of pressure. When water is 

 forced into the anterior chamber of an excised eye at a pressure of about 

 50 mm. Hg, the tension of the eye feels about the same as that of the human 

 eye. We are certain, therefore, that the normal intraocular pressure is 

 much higher than has been supposed. 



In some of our experiments we have measured the intracranial pressure, 



