346 PREPARATION OF MARINE ANIMALS. shall cease to exist or if within such period the Club shall fail to perform or observe any one or more of the stipulations herein expressed or appearing to be performable or observable by them for the space of six calendar months after notice of such failure shall have been put up by the Corporation in the Museum then and in either of such cases the contents of the Museum shall become the property of the Corporation and the Corporation shall thereafter and thenceforth preserve and carry on the Museum as a permanent Institution and as a Local (Essex) and Educational Museum on the lines of the scheme laid down in Clause 10 of this Agreement. (12.) THE Corporation have been endeavouring to purchase some free- hold property for the erection of a Museum and from the negotiations it appears that the land is subject to certain covenants which cannot be removed and which might interfere with the Corporation using the land for the above- named purposes. The Corporation will at their own expense during the present Session apply to Parliament and endeavour to obtain powers authorizing them to build notwithstanding such Covenants. In the event of such powers not being obtained on or before the thirtieth day of August one thousand eight hundred and ninety eight this Agreement shall thereupon become absolutely void. IN WITNESS whereof the Corporation has caused its Corporate Seal to be hereunto affixed the day and year first above written. The Corporate Seal of the Mayor Aldermen and Burgesses of the County Borough of West Ham was hereunto affixed in the presence of W. Ivey Mayor Fred. E. Hilleary Town Clerk ON THE PREPARATION OF MARINE ANIMALS AS TRANSPARENT LANTERN- SLIDES. By H. C. SORBY, LL.D., F.R.S., F.L.S.. Sc. [Being Abstract of a Lecture delivered to the Club on May 21st, 1898.] THOUGH for some years I have prepared mounted animals by various chemical methods, it is only quite recently that I have seen the importance of a more complete development of such processes; and the cause of some of the reactions still remain to be explained. In all cases the specimens are properly arranged and dried on the glass, and almost always soaked in benzole and then mounted in Canada balsam, which not only makes them far more transparent, but preserves them from mites, and from the growth of mould, which soon occurs