526 PROCEEDINGS OF TIIE SOCIETY. 



Mr. Ingpen asked if Mr. Mayall considered that the appearance of 

 beading was due simply to the intermittence of the arc light and nothing 

 else? 



Mr. Mayall could nut say exactly to what it was due. hut he thought 

 unsteadiness in the light was not the sole cause, because he had seen it 

 with the incandescent electric lamp — which was what Dr. Van Heurck 

 used — and this was one of the steadiest lights known. He had also 

 seen it with the oxyhydrogen light, and with sunlight he had seen it 

 very well indeed. Whether it was a false impression or not was another 

 matter. 



Mr. Crisp said that at the last meeting Prof. Stewart referred to 

 some slides said to he mounted in " Suffolk." and that Mr. Suffolk, who 

 was present, whilst disclaiming all knowledge of the matter, thought it 

 might possibly he something which he had at some time or other recom- 

 mended. Since then they had receive J a letter from Mr. J. W. Gooch, 

 giving the explanation that an old friend of his who lived in the county 

 of Suffolk invented this medium, hut would never divulge the secret 

 of its composition, and when any one pressed him as to what the slides 

 were mounted in, he used to reply that " they were mounted in Suffolk." 

 Hence the term came to he applied as if it was the name of the medium. 



Mr. Crisp referred to Prof. Raker's suggestions in ' Nature, ' with 

 reference to the use of the term '•micromillimetiv." and reported that the 

 Council, alter some consideration of the subject, had ultimately deter- 

 mined to recommend the abandonment of " micromillimetre,'' and the 

 use of the term •■micron'" to indicate the 1, 1000th part of a millimetre 

 [supra, p. 502 . 



Mr. A. Meates's paper "On a new Mounting Medium of High Refrac- 

 tive Index" was read by Mr. Ingpen. who said that Mr. Meates would he 

 phased to correspond with any Fellow who miglit he interested in the 

 suhject, or he would he glad to assist them in mounting any difficult 

 diatoms in this medium (supra, p. 519). 



Mr. Crisp read a letter front Mr. Julien Dehy, explaining the process 

 of ohtaining photomicrographs employed by Messrs. Truan y Luard 

 and 0. Witt, who stated that when an amplification of 500 diameters 

 was required, the hest results were ohtained by making a negative of 

 100 diameters with a low power, which could then he enlarged to 

 500 diameters hv an ordinary photographic copying process. {Ante, 

 p. 295.) 



Mr. T. C. White said he had already tried that plan, hut it required 

 the original photograph to be so remarkably sharp that very few persons 

 were likely to succeed in doing it to their satisfaction. 



Mr. Crisp inquired whether any one present had any experience of 

 the advantage to be obtained by photographing an object x 100 and 

 then enlarging it x 5 ? 



Mr. T. C. White said he would himself much rather take it with the 

 higher magnification at once. 



The Chairman asked if taking it upon the larger scale would not 

 involve an inconvenient loss of light. 



Mr. T. C. White said they certainly would lose light, hut that only 



