296 



llEINICKE, " Z. NEUERN MIKROSKOPIE. 



as it were of the diatom^ without any markings at all — this 

 is the interposed frame. 2. A similar form with sharply 



defined outline, but with a well-marked longitudinal line, and 

 having the entire surface covered with fine transverse lines. 

 These lines however he has hitherto been unable to count, not 

 having any objective capable of bringing them out clearly 

 enough; and he would be much obliged, he says, to anyone who 

 may be more successful, and whowould communicate his results 

 to him. 3. The third form (c) presents a much thicker outline, 

 and a very strongly defined longitudinal costa. This is the 

 complete diatom, consisting of the two valves, on which it is 

 usually more difficult to bring out the fine lines, and it con- 

 sequently should not be taken as the proper test-object. 



3. The third article also, or that on atmospheric micrography, 

 is merely a translation of M. Pouchet^s observations on this 

 subject, which have already appeared in our pages."^ 



The fourth article consists of a new method of preparing 

 algse and other very delicate and soft objects, especially parts 

 of plants, &c., by C. A. Hantzsch. The method, however, does 

 not appear to be very new in this country, however advan- 

 tageous it may doubtless prove. It depends upon the principle 

 that, in order to prevent the shrinking of soft tissues when 

 they are immersed in a dense, non-drying fluid, such as 

 glycerine, or a solution of chloride of calcium, it is necessary 

 to add those media very gradually. The way this is eflTected 

 by M. Hantzsch is as follows : 



The mixture he em])loys consists of — 



3 Parts 

 2 » 

 1 „ 



Alcohol (90° 



"Water 



Glycerine. 



* 'Quart. Jouin. Mic. Sc.,' No. XXII. 



