1886.] 



MICKOSCOPICAL JOUKNAL. 



137 



ditions) ,* and ft'esh butter fat is not 

 crystalline, the detection of the adul- 

 teration by the microscope seems not 

 to be an impossibility. It is because 

 of those well-known facts, as well as 

 of the clear understanding of them 

 manifested in Dr. Taylor's articles, 

 that we are inclined to put faith in 

 his statements. Going a step further, 

 it appears that butter also can be 

 recognized by its cr3'Stalline form 

 when mixed with other fats. The 

 admirable manner in wdiich Dr. 

 Taylor seems to have succeeded in 

 detecting adulterations in butter, en- 

 titles him to the credit of a discoverer 

 of a new process of analysis. 



o 



Cutting Sections of Minute 

 Organisms.— Dr. G. W. M. Giles 

 has recently contributed an interest- 

 ing article on Marine Collecting 

 with Surface Net to Science Gos- 

 sip The special part of the article 

 to which we wish to direct at- 

 tention is a method of preparing 

 sections of minute animals, such as 

 the smaller entomostraca for exam- 

 ple, which at first sight seems rather 

 impracticable, but which the writer 

 assures us has been successful in 

 practice. The hard shells and chiti- 

 nous coats of these animals offer 

 some difliculties in cutting when em- 

 bedded in paraffin, but occasionally 

 good sections can be cut in the man- 

 ner described, when the animals are 

 very minute. The method is as fol- 

 lows : Take the animal from absolute 

 alcohol, pass it through oil of cloves, 

 place it in a watch-glass with a few 

 drops of balsam, and heat until the 

 oil of cloves is entii^ely displaced by 

 the balsam. A single drop of balsam 

 is then heated on a slide until it is 

 hard when cooled. ' Now take up 

 the animal, together with a bead of 

 balsam on the point of a needle, and 

 place it on the balsam on the slide, 

 previously warmed, and pi'op it up in 

 such a position that the plane of the 

 sections desired may be parallel to 

 that of the slide, holding it thus until 



" See Amer. Quar. Micr. Journ., i, 295. 



the balsam has cooled sufficiently to 

 keep it so.' 



Sections are then cut with a razor 

 and dropped upon the slide and 

 mounted imder a large cover-glass. 

 The difficulty is to get the balsam 

 hardened just right. It must be just 

 right to be cut with a razor, and not 

 brittle. Sections of coralline algte 

 can also be made in this way. 



NOTES. 



— Several serious typographical errors 

 occurred in the communication on ' Fine 

 Measurements,' from M. D. Ewell,in the 

 June number, which our readers will do 

 well to note. 



Page 120: — 1 6th line, for fihn read filar ; 

 20th line, for Huygheinan read Huyghe- 

 nian ; 27th line, for solid read ruled; 28th 

 line, for sold read ruled. 



— Mr. Zentmayer has issued the ninth 

 edition of his Illustrated Price List of Micro- 

 scopes, and other optical instruments. 

 His present list now embodies the results 

 of more than forty-one years of experience 

 in the manufacture of optical instruments. 

 No instruments made anywhere in the 

 world more justly deserve their reputation 

 for excellence of workmanship and dura- 

 bility than do those of Mr. Zentmayer. 

 Among the microscopes recently intro- 

 duced by him, the ' portable histological ' 

 stand is already well known and popular. 

 We also notice a new illustration of a 

 cobweb micrometer in this edition. 



— Mr. J. Grunow has issued a new 

 price list of objectives, dated Dec, 1885, 

 in which he makes the announcement 

 that he has ceased to make water-im- 

 mersion lenses, and all his immersion 

 lenses are made for a fluid, having the 

 refractive index of crown glass, which 

 he prepares of an oily nature so that it 

 will not run like oil of cedar. It is less 

 fluid than any of the oils. He makes 

 J^ an Y5-inch objectives of balsam angle 

 115° N. A. 1.24. 



— The Palmer Slide Company has 

 issued a new circular concerning the 

 excellent and cheap slides they are 

 making upon their improved grinding 

 and pohshing machines. They also 

 furnish cover-glasses, mounting media, 

 staining fluids, and other articles. They 

 offer Prof Smith's new mounting media, 

 prepared under his personal supervision. 



