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might be done. The ordinary process of grinding was no doubt necessary for 

 obtaining sections of considerable extent, but it was not adapted for making 

 sections of the soft tissues in contact with the hard j as, for instance, of the 

 soft dentinal pulp as well as of the hard dentine in contact with it. By the 

 ordinary method the grinding either entirely destroys or obliterates the struc- 

 ture of the soft pulp, so that it is found that a section of the pulp, with the 

 dentine in contact with it, as in the recent state, cannot be made successfully 

 in that way. It was not, however, generally known that these hard textures 

 might be softened by soaking them for a long time in glycerine ; bone could be 

 softened by soaking it in glycerine for twelve months, and to such an extent 

 that it could be cut with a sharp knife with the greatest ease, so that sections 

 could thus be obtained sufficiently thin to be examined with a l-25th inch 

 objective, and under this power much more could be learned with regard to the 

 minute structure of such specimens than under a lower power. In the case of 

 the stones of fruits, in order to make out their structure it was absolutely neces- 

 sary to obtain sections in the recent state, and these must be cut and not 

 obtained by grinding, which would cause the complete destruction of the 

 texture, if it was in a growing and imperfectly formed state. Another mode of 

 great practical utility in investigating the structure of hard textures is to 

 soften them by soaking in glycerine, to which has been added some substance 

 which will act as a solvent of the hard portions of the tissue. By adding a little 

 hydrochloric acid to the glycerine (four or five drops to the ounce) bone could 

 be very readily softened, and by prolonging the action it became possible to 

 make out exactly the order in which the calcareous matter had been deposited. 

 When a small quantity of the calcareous matter had been dissolved away, you 

 could cut thin sections with a knife without difficulty. Acetic acid was also a 

 valuable agent for this purpose. If it was desired to examine the nerve fibres 

 in hard tissues, such as teeth, in which they would be completely destroyed by 

 the ordinary method of investigation, this process might be adopted with 

 advantage. If soaked for some time in a mixture of glycerine and acetic acid 

 it would be found that the acid would soften the hard texture, whilst the 

 glycerine would preserve the nerve fibres intact, and sections could be cut with 

 a sharp knife with facility, and in any direction that was desired. These were 

 some little practical points which he had found useful in making thin sections 

 of hard tissues. Those who attempted these methods must be content with 

 sections of small extent only, as large ones could not be nicely cut with a knife . 

 This, however, was a matter of not very much importance, because if a person 

 made out what might be termed the geography of a large specimen obtained in 

 the way recommended by Mr. White, he could easily make out the minute 

 structure by means of small sections cut in the manner described. As a study 

 for young microscopists, there could hardly be one more interesting than that 

 of the development of the hard stones of fruit, or the hard shell of a nut, or a 

 walnut. Mr Quekett and others had perhaps ascertained all that was to be 

 demonstrated coucerning the structure of the dried fully formed shells which 

 had been ground down to thin sections, but a vast deal had yet to be learned as 

 to the manner in which those hard tissues were formed during development. 

 He was quite sure that a great deal might be done in this branch of investi- 

 gation, and he strongly recommended the subject to the attention of members 

 of the Club. 



Mr. White said that he could fully corroborate all that Dr. Beale had said. 

 After using glycerine and acetic acid, as recommended, the tooth became so 



