Fresh acid urine of Mrs. J. L. S. kept over night. -Colored blood cells-distinctly reticulated, partly budding, haemoglobin extracted. Sediment acid urine from haemorrhaic pyelitis due to calcium oxalate calculus, fixed with 1-5 of 1 per cent. chromic acid and preserved for 10 years in glycerin. a-Colored corpuscle-distinctly reticulated. I b-Haematoblasts-abundant. -Pus corpuscles (poor constitution). a d Fresh acid urine of Mrs. L. J. H. (Speec. grav. 124) kept over night. a-Colored blood cell. b-Pus corpuscles of excellent constitution (scarce). c-Pus corpuscles of good constitution. d-Pus corpuscles of middling constitution. e-Pus corpuscles of poor constitution. Fresh blood of J. H. L. in moist chamber mixed with a b-Crenation and formation of platelets. DISCUSSION. Dr. Wm. H. Porter: Mr. President and Gentlemen of the Vermont State Medical Society :-I hardly think it would be possible for me to add anything to what has already been said concerning the examination of the blood. All I can do is to give my testimony in the same line. I am surprised, I must confess, to hear that anyone believes at the present day that they can analyze blood stains with any degree of accuracy. It is not possible to be sure that it is blood stains, even by the presence of what appear to be corpuscles, and I cannot see how any one would be willing to swear that he had blood stains with only one point in evidence, without the other two points in evidence. In a general way, they might very easily think it was blood, but where the life of an individual is in question, I should think they would hesitate before giving a positive opinion. In a case of that kind, the individual should most certainly have the benefit of the doubt. While it is generally recognized that we can diagnosticate the corpuscles of the different kinds of animals by the use of proper instruments, taking plenty of fresh blood, it is not possible when the blood is dry and the corpuscles have become more or less contracted, to say that the blood is that of a man, or even that of one of the lower animals whose blood so closely resembles that of man. I must say that I agree most emphatically with Dr. Linsley that we are unable to give any definite analysis of the blood at the present time. Dr. J. Henry Jackson: Mr. President and Gentlemen :--“ I wish to say just a word to correct an impression and relieve anxiety on the part of Dr. Porter; that is, that the examination to which Dr. Linsley referred in his very excellent paper-in a case where it was declared that the examination of the blood could be so accurately made as to determine positively that it was human blood,—if I understand the doctor, was made in 1875, or about twenty years ago, and so need not give the doctor any apprehension as to the reliability of the expert of to-day in regard to determining whether a given stain be blood or not. I have been listening very interestedly to the presentation of this subject by Dr. Linsley, and I think it will leave us with a better impression without further remarks from me. The logical and physical examination and appearances of the blood have been clearly brought out in the doctor's paper, and nothing I can say in regard to the subject will improve your understanding of it. I wish to thank Dr. Linsley for his very excellent representation of this work." Dr. J. N. Jenne : "Mr. President and Gentlemen :-I have been very greatly interested in this paper so ably presented by our President and I wish to consume but a moment's time in the matter of its discussion. However, there is one point which has been raised here, and that particularly with reference to the value of the result of the examination of the blood. After there has been a thorough chemical analysis and microscopic examination, one should then be able to meet the question as it appears in medical and legal cases. I assume that it is not necessary in any instance for the expert who is called, to inquire into the circumstances presented to him by the officers of the state, and as a matter of fact it is not often that he is called upon to state that the stain is the blood of any special animal. He certainly should not, in our present state of knowledge presume to be able to determine that the stain is the blood of any specific animal; but having undertaken to do it, he is in duty bound to apply all the knowledge as far as possible to determine. The statements with reference to the value of a microscopical examination, and the fact of finding whether the corpuscles were present, and the opinion given that it was blood or otherwise, were made with reference to that examination alone without reference to any other examination. I can conceive how an examination made in that manner might lead to the results stated in the doctor's paper; but taking a given stain and applying the Guaiac test, or any other chemical test, or both, and having got the reactions which are characteristic of the presence of blood and demonstrative the haematin crystals, and verifying this by finding the corpuscles, if skillful enough by spectroscopic test, then one can say that the specimen is blood; and further examining the specimen with the microscope and finding corpuscles that correspond with any given species, he may state what his examination has evinced. I do not mean that any blood can be submitted to these tests and determined to be the blood of the exact animal from which it was taken; but with proper instruments, you can determine that it is not the blood of certain animals. It is possible that the test may be applied and no reaction given by any one of the tests whereby you could say that the stain was blood. These same conditions could be present in any old stain, as age and other circumstances connected with blood drying, and treatment in the redissolving of the corpuscles, may destroy them, that is, change their diameter so that it would, under these circumstances, be absolutely impossible by these tests to determine the fact of blood, further than that it was mammalian or otherwise, and you would be able to declare it the blood of a given species. It is certain then that the spectroscopic tests can be made and will generally reveal the presence of hæmatin crystals, and if the hæmatin crystals of Zieshman, so-called, did not show, and the conditions that destroyed the corpuscles were present, it would then be impossible to say that a given stain was blood. So that in a given specimen, if the hæmatin |