Injury, recovery, and death, in relation to conductivity and permeability . istance was only 30 ohms below the resistanceof the control, which at the beginning of the experimentwas 810 ohms. The results are presented in Fig. 33. The successful out<3ome of this experiment led to anattempt to carry on such an experiment for several daysin succession, giving the tissue one treatment daily withNaCl. The material was selected with especial care. Thefronds were fairly thick, without reproductive experiment was made at Woods Hole, Mass., in July,at which time such fronds may be easily o
Injury, recovery, and death, in relation to conductivity and permeability . istance was only 30 ohms below the resistanceof the control, which at the beginning of the experimentwas 810 ohms. The results are presented in Fig. 33. The successful out<3ome of this experiment led to anattempt to carry on such an experiment for several daysin succession, giving the tissue one treatment daily withNaCl. The material was selected with especial care. Thefronds were fairly thick, without reproductive experiment was made at Woods Hole, Mass., in July,at which time such fronds may be easily obtained. Thedisks cut from these fronds were slightly curved, so thatwhen placed in the apparatus they separated spontan- 82 INJUEY, EECOVERY, AND DEATH eously, thus allowing the running sea water in which theywere kept to circulate freely between them. Care wastaken to keep them only about two-thirds submerged, sothat they had free access to air, but ran no risk ofdrying up. The tissue in sea water had a net resistanceof 780 ohms at 20° C. As the temperature of the BAY. IS 30 Fro. 34.—Graph showing loss of net electrical resistance of Laminaria agardhii in M (unbroken lines) and recovery in sea water (broken lines) on 16 successive days. Allreadings were made^at 20° C. or corrected; to this temperature. Each graph represents a single experiment. sea water varied but slightly from this during the experi-ment, all readings were taken at 20° C. On beingplaced in NaCl M, the resistance fell in 5 minutes ; the tissue was then placed in sea water, and areading taken 10 minutes later showed that it had risenagain to the normal. The tissue was then placed in run-ning sea water, with the precautions mentioned the end of 22 hours the resistance was 780 ohms. Anexposure of 5 minutes to NaCl resulted in a drop to ,.with complete recovery within 10 minutes. The sametreatment was given once each day for 15 days. On thetenth day the resistance began t
Size: 2183px × 1145px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectphysiology, bookyear1
