FEIiRUAEY 1, 1895.] 



SCIENCE. 



ir 



A Study of the Operative Treatment for Loss of 



Nerve Hubstaiice in Peripheral Nerves. G. 



Carl Hcber. (Introduced by AV. P. 



Lombard.) 



The report covered the results obtained 

 in 50 experiments on dogs, in which tlie 

 various methods that might be employed in 

 the surgical treatment of divided peripheral 

 nerves, where there is loss of nerve sub- 

 stance to the extent that an ordinary suture 

 cannot be made, were tried. Segments va- 

 rying in length from 5—8 cm were removed 

 from the ulnar and sciatic nerves of the 

 dogs. In 26 experiments a portion of an- 

 other nerve (usually the sciatic of a cat) 

 was implanted between the resected ends 

 of the nerve operated upon, and retained in 

 place by means of sutures ; in 8 experiments 

 the resected ends were united bj' means of 

 decalcified bone tubes ; in 7 they were 

 united with a number of catgut threads; a 

 tlap from the peripheral end of the cen- 

 tral stump was made in 7 experiments ; and 

 grafting the central end of the peripheral 

 portion of a rese<'ted nerve to an accompa- 

 nying nerve trunk was tried twice. After 

 carefully closing the wounds, the animals 

 were allowed to live for periods varying 

 from 2 to 182 days ; before killing the ani- 

 mals the nerves operated upon were tested 

 as to their conductivity; thej* were then 

 removed and prepared for histological ex- 

 amination. 



1. In all experiments the peripheral por- 

 tion of the divided nerve degenerated, as also 

 i cm. of the distal end of the central stump. 



2. Regeneration was obtained after in- 

 plautation of a nerve segment, tubular 

 suture and suture ') distance with catgut 

 threads. 



."5. Regeneration was from the central 

 end, buds given otV from the central axis 

 cylinders growing toward the periphery. 



4. The implanted substance serves only 

 a.s a guide to the down gi-owing axis. 



5, Regeneration takes place most rapidly 



(120 to l.'JO days in dogs) after implanta- 

 tion of a nerve segment. 

 Demon.4ration of a Neiv Gas Pump for the Ex- 

 traction of Blood-Gashes. G. T. Kemp. 

 Dr. Kemp exhibited and explained the 

 action of a new form of gas-pump. This 

 pump is, except for slight modifications, a 

 combination of the Sprengel jnimp with the 

 Xeeson and IJessel-Hagen additions to the 

 Toepler pump. The large bulb is used in 

 accordance with a suggestion of Pfliiger and 

 is about the size of those in the large pumps 

 used in the laboratorj- at Bonn. The pump 

 is made in two halves for ease of transporta- 

 tion. The vacuum space on each side of the 

 bulb prevents the mercury from spitting 

 back into the bulb, during the first few low- 

 erings of the reservoir, as occui-s in the Nee- 

 son-Bessel-Hagen-Toepler pump. The ad- 

 vantage of this form of pump over all pat- 

 terns which have a 3-way stopcock at the top 

 of the bull), is that there is no danger of 

 smashing the stopcock fi-om the impact of the 

 mercury, and tlie pump can be worked very 

 much faster. No precaution has to be taken 

 against raising the reservoir bulb too rap- 

 idly. 



The Sprengel attachment can be made to 

 work either separately or together with the 

 other part of tlie pumj). 



There is no stopcock which is not com- 

 pletely under mercury seal, so that leakage 

 is out of the ((uestion. 



The essential re(iuisite of such a pump is 

 to extract all the oxygen as soon as possible, 

 certainly before the blood clots, and to keep 

 the tension in the blood bulb from rising 

 above 20 mm, of mercury, as this prevent.s 

 the complete disassociation of the oxygen 

 from the oxyhaemoglobin. When blood is 

 drawn into the vacuum the oxygen is given 

 oft" very rapidly, in a 'puff.' so to speak, 

 and the carbon dioxide is given oft" more 

 slowly and regularly. By having a large 

 Hg bulb which can be filled and emptied 

 rapidly, the exhaustion can easily be main- 



