52 MEMOIRS NATIONAL ACADEMY OF SCIENCES, VOL. X, NO. 3. 



An examination of the experiments of this series will show that alcohol under the circumstances 

 produced no constant influence upon the circulation. The results were very unsatisfactory so far 

 as the circulation is concerned, because of the enormous disturbance of the respiration and of 

 the general system produced by the tying of the aorta. There was so much unrest and motion, 

 and the circulation was so irregular, that the series is probably of no value as throwing light 

 upon the action of alcohol upon the circulation. These experiments ought to be repeated upon 

 curarized dogs, with artificial respiration, if any weight at all is to be attached to them. 



The conditions under any circumstances, however, are so abnormal that it has not seemed 

 to us that any results reached would be of importance, and we have therefore not carried this 

 matter to a further conclusion. 



STROMUHR. 



Over twenty-five years ago Dr. H. C. Wood asked Professor Schmiedeberg, in his labora- 

 tory at Strassburg, to show him how to use Ludwig's stromuhr; the reply was, -v Nobody can 

 use the stromuhr except Professor Ludwig, and Ludwig himself could not do so if it woe not 

 for his diener Hans. So Doctor Wood went to Leipzig, told the story to Professor Ludwig, 

 who with considerable glee called Hans and said: '''Hans, Schmiedebekc says I could not use 

 the stromuhr if it was not for you; that you are the man who does it; so show the professor 

 how." 



There are, however, no excessive practical difficulties in the use of the stromuhr, provided 

 complete destruction of the coagulability of the blood be secured. In the present work we found 

 great difficulty in preventing the coagulation of the blood in or about the tubes of the stromuhr. 

 The rabbit is so small an animal that it did not seem to us wise to employ it, so all our experi- 

 ments were made with dogs. 



Wittee's peptone was given intravenously to the amount of over 3 grams per kilo to the 

 dog without sufficient result on the blood to make the experiment workable. Leech extract, or 

 the active principle of the leech salivary gland, we were unable to buy in the American market. 

 Following the method recommended by Franz as closely as we could did not bring the desired 

 result for reasons that are not clear to us. We succeeded, however, in getting successful 

 experiments by using the following plan, based upon the work of Franz: According to the 

 statements of Franz, the active anticoagulating principle of the leech is most largely situated 

 in the salivary glands anterior to the tenth ring, but is also to a greater or less extent diffused 

 through the rest of the body. We found it very difficult with our laboratory centrifuge to 

 properly act upon a large gummous mass such as that formed with the whole of the leech, 

 whereas the centrifuge acted well with the leech heads. 



We therefore cut off the heads of the leeches, cut them into very small pieces, rubbed 

 them up with very tine sand, and to the mass added 5 c.c. of a seven-tenths per cent normal salt 

 solution for each leech represented. This was heated for twenty minutes over a w T ater bath at 

 212°. The bodies of the leeches we treated in the same manner as the heads, and the two separate 

 masses were allowed to stand in a room of low temperature for twelve hours. The mass contain- 

 ing the leech heads was then centrifuged for twenty minutes; the sand contained in the lower 

 portion of the centrifuge was then washed, the wash liquid centrifuged, and the two fluids obtained 

 added together. The mass containing the bodies of the leeches was filtered through cheese cloth 

 under pressure; the filtrate was then centrifuged. The mass was again washed with salt solu- 

 tion, the filtrate centrifuged, and the two results obtained added. The fluids obtained from the 

 heads were now added to those derived from the bodies, and the two constituted the liquid leech 

 extract which was injected. 



For obvious reasons no definite amount of the saline was used in making the leech extracts, 

 consequently the dose of the solution given to the dog was measured b} r the number of leeches 

 represented and not by the number of cubic centimeters of the solution injected. Franz states 

 three leeches per kilo as the amount necessary to prevent coagulation; the lowest amount with 

 which we were successful was three and a half leeches per kilo, but it is very probable that the 

 fresh European leech contains more of the active principle than do such travelled leeches as we 



