The cell theory past and present Author:William Turner Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: include persons interested in every department of knowledge in which the instrument is or can be employed. We shall be glad to hear communications on the optical... more » principles which guide the maker in the construction and improvement of lenses. We shall welcome into our body those who are engaged in the manufacture of the instrument and its various appliances, especially if they will communicate to our Proceedings the particulars of improvements in it, or in any of its associated apparatus. We shall be delighted to receive communications on new and better methods of preparing and displaying specimens, so that they may be examined with more exactitude. All advances in microscopic technique will be welcomed by us. But we must not stop here. Improvements in the instrument are not the main end and object of our existence. Our great duty is to advance those sciences in which the instrument is employed ; to probe to their very depths the secret places of nature, and to do our best to advance knowledge. We shall have to inquire into the structure of plants and animals in conditions both of health and disease—to investigate the changes which take place in them in connection with the discharge of their respective functions. Those of our members who are engaged in geological and mineralogical studies will doubtless communicate to us the result of their researches into the microscopic structure of rocks and minerals, and the form of their constituent crystals. Manufacturers of textile fabrics may also have something to say on the economic applications of the instrument; whilst those who take a delight in testing the powers of their objectives can bring before us any new object, the markings on which their instruments are capable of resolving, and which may furnish perhaps a more satisfactory...« less