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to cut sections from properly ; but when frozen it could be cut without any 

 trouble. He had found a saturated solution of gum with a few drops of camphor 

 added bo it to be a good medium, as the gum did not splinter up when cut. 

 Pounded ice and salt were used as a freezing mixture. The box containing the 

 freezing mixture need not, he thought, be on both sides of the machine. He 

 did not use the indicator himself, nor did he place a high value upon it, but 

 rather preferred to trust to the touch. He thought that the gooo iii' which had 

 been mentioned, would certainly spoil most anatomical tissues, for the size of 

 the blood disc, which might be taken as the anatomical unit, was the 3000 of an 

 inch, and a section thinner than that was not often of use. As to the razor, he 

 liked it best with a straight edge and a blade narrow at the point and broad at 

 the heel. He did not think it possible to cut a good section merely by a push ; 

 the cut must be made obliquely, and no machine could give the obliquity with 

 such precision as the hand. The so-called American machine was really the 

 invention of Van Hausen, of Kiel. In the matter of hardening, he did not think 

 that absolute alcohol was necessary ; indeed, methyl alcohol was preferable, if 

 it was intended to mount in balsam. There was a little water in it, but this did 

 not matter, as evaporation took it off. For staining. Dr. Beale's carmine was 

 now almost always used. Success in staining depended upon taking the tissue 

 out of the hardening solution at exactly the right time. He had seen it done in 

 three quarters of an hour. It was advisable to remove as much of the chromic 

 acid as possible first. 



Dr. Matthews said that the first requisite in section cutting was to have a 

 firm support. All wax in cooling shrunk away, and in some cases to such an 

 extent as not to imprison the object with sufficient firmness for the purpose. 

 Specimens of spinal cord would sometimes even turn round in it. This might 

 partly be obviated by using parafiin wax in preference to bee's wax. Then as to 

 the material for the plate, it was a well-known axiom in mechanics that dis- 

 similar metals should ahvays be used for friction upon each other; so that 

 according to this, brass or gun metal should be used, although they had been 

 said to fail, because, if the curved edge of the cutting instrument were in the 

 slightest degree depressed too much, it caused the plate to be cut iato. Another 

 cause of this was that the blade of the razor was often slightly flexible ; this 

 would give it a tendency to dip and cut into the plate, and would cause its edge 

 to impinge upon the edges of the aperture. The exact thickness of the section, 

 after soaking in alcohol, could never be relied on. He believed that many false 

 appearances had been produced by alcohol and chromic acid; in preparations 

 illustrating sclerosis it was found that some alterations which took place were 

 not the result of a pathological process, but the effect of the hardening by 

 alcohol. In staining, the great principle to be remembered was that the fluid 

 must be alkaline. 



Dr. George Hoggan said that as he came almost direct from the College of 

 France, it might be of interest to the meeting to hear what methods were 

 adopted there at the present time. Judging from the opinions expressed that 

 evening, wax had appareiitly been settled upon as the best substance for imbed- 

 ding the tissue ; he considered, however, that carrot was for this purpose far 

 superior to wax. The pith of the elder was better still ; and, indeed, he believed 

 this to be the best of all. For hardening tissues, they placed most reliance in 

 France upon a saturated so'ution of picric acid. They would place such a sub- 

 stance as a tumour in methyl alcohol for 48 hours, then in the picric acid 

 Bolution for 48 hours, then in a solution of gum, of the consistency of syrup, 

 for 48 hours, and then in the original alcohol for 48 hours, and for any time 



