1 '.-_' Prof. C. S. Sherrington. On C/uwg'* in tht Blood 



The animal being deeply anaesthetised, the nerves to the limb have 

 been carefully severed, in order to destroy sensation in the limb. 

 Then the main artery to the limb (femoral or brachial) has been 

 occluded by digital compression, and the extremity of the member 

 immersed in water at 52 C. for five minutes. The limb has then 

 been wiped dry, the animal allowed to recover from anaesthesia, and 

 replaced in its stall. 



The blood was examined at least once before establishment of the 

 lesion. Afterwards a series of examinations were made, and these, 

 with records of body-temperature and respiration, furnish the chief 

 observations obtained from the experiments. 



When the site of the lesion has been in an abdominal organ the 

 same general plan has been followed, except that, as a rule, no nerve 

 has been severed. Sponges steeped in 0'6 per cent, aqueous NaCl solu- 

 tion at 52 C. were applied for five minutes to a knuckle of intestine, 

 brought to a small incision in the linea alba ; the gut was then care- 

 fully replaced, and the wound closed, the whole performed with strict 

 precautions for asepsis. In several instances, instead of the above 

 plan, mechanical trauma was employed in the form of ligation of 

 knuckle of intestine. In several experiments where inflammation, 

 primarily of a mucous surface, was requisite, vise was made of specific 

 chemical irritants in the form of cathartics administered by the 

 stomach ; but I have for the present endeavoured to avoid the use of 

 chemical and bacterial irritants. 



For the examination of the blood " drop " methods have been used 

 throughout ; the withdrawal of even quite small quantities of blood 

 from the circulation induces rapid alteration in the circulating blood 

 itself. By "drop" methods this source of error is avoided. More- 

 over " drop " methods have the advantage of not necessitating any 

 binding down or tying of the animal, and it has by several authori- 

 ties* been shown that these fixations of the animal, especially when 

 continued over longish periods, induce of themselves severe changes 

 in the composition of the blood. The animals employed have beei 

 the dog and cat, and occasionally the rabbit. The drop of blood 

 required for examination has been almost always taken from the pinna 

 of the ear. 



For the counting of corpuscle* I have used a selected pair of previously tested 

 Thoma-Zeiss " counters." The instruments are guaranteed to vary in capacity by 

 Ion than 1 per cent, of the capacity of each, i.e., by less than 0*001 mm.. My pair 

 showed no difference measurable under the magnification of the Zeiss Objective D. 

 I have therefore discarded enumerations which have not tallied on the two counters 

 within 10 per cent. I have not used the Thoma- Zeiss pipette, but one by Hawksley, 

 containing no bead, and of a different shape from the Thoma-Zeiss pipette. Objec- 



Cf. especially Lowit, ' Studien zur Physiologic u. Pathologic de Blutes u. 

 Lymphe,' p. 9, 4c. 



