186 PHILOSOPHICAL TRANSACTIONS. [anNO I667. 



On the Mendip Lead Mines. By Mr. Joseph Gl anvil. 



N' 28, p. 525. 



In answer to former queries concerning mines, this gentleman replies. That 

 Mendip is all mountainous. That it is barren and cold, and in some places 

 rocky. That the ridges run confusedly, but mostly east and west. Its surface 

 is heathy, ferny and furzy. 



Experiment 3. Two pounds of blood were taken from a large pointer who had been previously 

 weighed^ and three pounds of sheep's blood from the jugular vein introduced. Dr. Harwood had been 

 in the habit of letting out the superabundant blood when any of the animals had received too much, 

 but in this experiment, it was suggested by the Rev. Mr. Midcalf, then fellow of Christ's College, 

 that it would be curious to observe the effect which would follow such an extraordinary degree of ar- 

 tificial plethora as the introduction of an additional pound of blood (into the circulating system of an 

 animal who had naturally not more than five) must necessarily occasion. The vein was accordingly 

 secured in the usual way, and the dog being released ran into the court, and immediately attempted 

 to relieve himself from this unusual plenitude by every possible evacuation. His efforts to accomplish 

 this purpose not proving successful, he became still more uneasy and restless, and afterwards drowsy 

 and stupid. These symptoms were succeeded or rather accompanied by a considerable degree of fever, 

 which terminated in a copious evacuation of blood by stool, by urine, and by vomiting. He took no 

 nourishment for three days after the operation, except pure water, and was more reduced than Dr. 

 H. ever saw an animal in that space of time. He now drank a little milk, and afterwards some broth, 

 from which time he gradually recovered his appetite and strength, and remained in good health for 

 several years. 



Experiment 4. All the blood of a pointer was let out (as far as it was possible to evacuate it) till 

 the animal was in convulsions on the table, and apparently expiring. The blood was then transfused 

 from the jugular of a sheep into the correspondent vein of the dog, and in less than half a minute 

 after the introduction of the tube, he began to respire, and as soon as he had received a quantity of 

 sheep's blood equal to what he had lost of his own, he leaped from the table and walked home, with- 

 out experiencing any apparent inconvenience eitlier then or at any subsequent period. This experi- 

 ment was performed before a very crouded meeting at the public schools in the Botanic garden of tlie 

 university. It has been frequently repeated since, and a variety of otlier animals have been subjected 

 to the same experiments, and with equal success. 



As the nature of our design will not admit of our relating a greater number of Professor Harwood's 

 experiments, we shall close this article witli a few patliological remarks from that gentleman. 



From all the numerous experiments which have been lately made upon this subject, one important 

 fact seems to be fully established, that the blood of an herbivorous animal may be substituted for that 

 of a carnivorous animal, and vice versa, without danger, or even inconvenience to the animal who re- 

 ceives it. In cases therefore of such copious evacuations of blood as to threaten the death of the pa- 

 tient, would not transfusion be expedient? and if death should be inevitable without it, does it not 

 become a duty to make the trial ? 



Professor Harwood is at present engaged in a course of experiments to ascertain whether diseases 

 may be communicated, or medicines conveyed into the system, by the transfusion of diseased or me- 

 dicated blood from one animal to another} which he will probably publish at some fiiture time, toge- 

 ther with a description of the easiest mode of performing the operation, and answers to all the objec- 

 tions which have hitherto been urged against the application of it on the human subject. 



