TJie Use of a Simple Microscope. 



29 



soaked in turpentine and then covered with Canada balsam, for 

 the manner of doing which directions will be found in the 

 ' Manual for Mounting,' &c. 



Specimens of various samples of linseed-cake, cotton-cake, 

 rape-cake, &:c., after having been treated with hot water, should 

 be put up either dry or in balsam, being at the same time 

 very carefully labelled with date, name, and any particulars of 

 manufacture, purchase, or effect in use, that may be connected 

 with them. Samples of crushed seeds known to be unadulterated 

 should be procured and preserved in the same way, as these 

 afford the only reliable evidence of the respective characters of 

 each, and will at once prove the presence of extraneous substances 

 in manufactured cake. 



In the examination of seeds. Sic., and in the preparing sub- 

 stances for examination under the microscope, it is mostly 

 necessary to have the means of using the hands at the same time 

 that the object is seen under a magnifying glass, and for this 

 purpose the lens and holder. Fig. 14, may be used, but a con- 

 venient form of stand called a dissecting microscope is provided 

 on purpose, where every facility for manipulation has been 

 studied. 



Dr. Lawson's Binocular Dissecting Microscope. 



The most recent and best contrivance is the above binocular 

 dissecting microscope of Dr. Lavvson as made by Mr. Collins of 

 Tichfield-street.* In this both eyes are used, which gives the 

 object a more natural appearance, and, both hands being at 

 liberty, objects may be separated from one another, and vegetable 



* See 'Science Gossip' for September 1, 1SG5, p. 201. 



