470 Scientific Intelligence. 



African diamonds had been formed, it was necessary to surmise 

 that the crystals, after formation in the molten iron at some great 

 depth below the earth's surface, had floated into the molten 

 silicate-material above. It was, however, soon pointed out that 

 the diamond-bearing rock, if in a state of fusion at small pressure, 

 dissolves any diamonds contained in it." 



Dr. Friedlander fused a small piece of olivine, a centimeter in 

 diameter, by means of a gas-blowpipe, kept the upper portion in 

 the molten state for some time by playing upon it with the flame, 

 and stirred it with a little rod of graphite. After solidification 

 the silicate was found to contain a vast number of microscopic 

 crystals, but only in the part which had been in contact with the 

 carbon. These Dr. Friedlander has subjected to a careful ex- 

 amination. They are octahedral or tetrahedral in form, are un- 

 attacked by hydrofluoric and sulphuric acids, have a high refrac- 

 tive index, sink slowly in methylene-iodide, burn away when 

 heated in a current of oxygen, and are unaltered if heated in a 

 current of carbonic acid: the stony matter containing them 

 scratches corundum. Hence Dr. Friedlander infers that they are 

 diamond, and that the South African diamond may have been 

 actually formed, as already suggested, by the action of a molten 

 silicate, such as olivine, on graphite: carbonaceous shales are 

 interrupted by the diamond-bearing rock, and numerous frag- 

 ments of the shale, much altered, are found enclosed in the rock 

 itself. The paper is illustrated with seven micro-photographs. 



5. Contribution to the Petrography of the Boston Basin ; by 

 T. G. White (Proc. Boston Soc. Nat. Hist,, vol. xxviii, 117-156, 

 1897). — This article contains the results of a study under the 

 microscope of the petrographic characters of the complex of 

 rocks occurring in the Boston Basin district, especially those of 

 igneous types, and will be found of interest and service to those 

 engaged in the study of the local geology of that region, l. v. p. 



III. Botany. 



1. Mr. Walter Gardiner, of Clare College, Cambridge, con- 

 tinues in the Proceedings of the Royal Society, for Oct. 29th, 

 his researches into the structure of the cell-wall, with special refer- 

 ence to the mode of communication between cells. In 1883, Mr. 

 Gardiner pointed out the simple methods of demonstrating proto- 

 plasmic intercommunication in plants, and opened up a plain path 

 in which he has had many followers. It became evident early in 

 the minute study of this subject that the lines of communication 

 were by no means as simple as were at first naturally thought. 

 Improved methods of staiuing brought out new features, and 

 these suggestions led to still further advance. During all this 

 period Mr. Gardiner has devoted much time to the improvement 

 of methods, and he now publishes a preliminary paper on his 

 latest technique. In brief, the present method is as follows : 

 after causing the cell-walls to swell by any one or all three of the 

 agents usually employed, namely, picric acid, zinc chloride, or 



