256 PKOCEEDINGS OF SOCIETIES, 



wliich, when publislied, would throw great light on the life history 

 of diatoms. 



The evening then became a conversazione, when living diatoms and 

 a great variety of silicious valves from different localities were ex- 

 hibited by Dr. Hallifax, Messrs. Henuah, E. Glaisyer, and Wonfor. 



Mr. Hennah also exhibited some exquisite micro-photographs of 

 diatoms taken by Dr. Maddox, some of them magnified 3000 dia- 

 meters. 



South London Microscopical and Natural History Club. 



An Ordinary Meeting of this Club was held at Glo'ster Hall, 

 Glo'ster Place, Brixton Eoad, on Tuesday, August 15th, at half-past 

 seven o'clock in the evening. Dr. Braithwaite, F.L.S., presided. 



Four new members were balloted for,'and duly elected. 



Dr. Hector Helsham, F E.C.S., read a paper " On the Employ- 

 ment of the Microscope in Analysis," of which the following is an 

 abstract : — 



The subject of analysis embraces a vast field, for the microscope is 

 pre-eminently the instrument of analysis, and every application of it 

 an act of analysis, whether working out the minutiae of structure, 

 developing the growth of the smallest organism, or defining the con- 

 stitution of some inorganic particle. It will be advantageous therefore 

 to limit the api^lication of the term to the investigation into the quali- 

 ties of things, leadiug up to the establishment of facts, in contradis- 

 tinction to the tracing down to the originals of form and structure in 

 physiological and biological sciences. 



It is my purpose, then, to consider the application of the micro- 

 scope to the detection of the minutest organisms in nature, its ai:)plica- 

 tion to the detection of the results of diseased action, to adulteration, 

 and the detection of crime. 



To our unaided vision, animals and plants present differences of 

 form and structm-e by which we are able to distinguish one from the 

 other, aud by closer examination we find deeper evidences of variety 

 in their organization, and when we extend our survey still deeper, the 

 more extraordinary is the amount of minute organization in every 

 animal or vegetable production. These differences rightly observed 

 and rightly interpreted by the microscopist furnish an unfailing iden- 

 tity to every portion, however miniite, of vegetable and animal tissues, 

 aud enable us to refer them to their origin. Observe how much lias 

 grown out of the study of the starch-granule, how every structure 

 that contains it may be distinguished ; contrast, for the sake of dis- 

 tinction, the starch-granule of the 2^otato with that of rice, and note 

 the ready point of difference here established — applicable easily to 

 the examination of the purity of wheaten flour ; contrast also the 

 granules of Maranta, or West Indian arrowroot, and the granules of 

 the turmeric-root, favourite articles employed in adulterating si^ices. 

 We have thus by their study a reliable typical character on which to 

 verify our judgments. The starch-granule will also illustrate the 

 extent of study which may concentrate aromid one special object as to 



