508 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



have made many hundred and even thousands of attempts to duplicate 

 these results, up to very recently these two slides have remained 

 unique. After the Chautauqua meeting, where they were again the centre 

 of admiring crowds, I commenced a series of systematic experiments, 

 discarding old methods altogether, and can now announce that I have 

 found a method by which I can get slides, even more magnificent, with 

 absolute certainty ; and I have now in my cabinet a dozen, any one of 

 which distances in every respect the old preparations, magnificent and 

 beautiful as they were. I am continuing my experiments with other 

 crystallizable materials, and when they are completed will explain the 

 methods by which the results are obtained. I will say, however, that the 

 size and the form and method of growth of all crystals yet experimented 

 with are modified by the temperature at which crystallization takes place ; 

 the degree of saturation of the mother liquor or solution ; the position in 

 which rests the slip on which crystallization progresses ; the medium 

 used for solution ; and, finally, by the material used for retardation of 

 crystallization." 



L A T H A II, V. A. — Practical Notes on preparing Palates of Molluscs, Snails, &c. 



Sclent if. Enquirer., II. (1887) pp. 87-9. 

 Turner, W. B. — Desmids. [Directions for preparing.] 



Trans. Leeds Naturalists^ Club, 1886, pp. 16-8. 



(3) Cutting-, including' Imbedding' and Microtomes. 



Rutherford's Combined Ice and Ether-spray Freezing Microtome.* — 

 Prof. W. Rutherford's well-known microtome is now adapted for freezing 



Fig. 148. 



by means of an ether-spray apparatus, as well as by the original ice and 

 salt method. 



* Lancet, 188.% i. pp. 4-6 (2 figs.). 



