1882.] 



MICROSCOPICAL JOURNAL. 



157 



finest pseudopodia. Heliozoa are also 

 perfectly preserved in this way. 



Bernard Landsberg* objects to the 

 above process because all the opera- 

 tions are performed under the cover- 

 glass, which renders it impossible to 

 remove dirt, etc. He recommends 

 the following ingenious method which 

 requires no great operative skill, as 

 even beginners in microscopy readily 

 succeed with it. The water is exam- 

 ined on a slide, or in a watch-glass, 

 under the microscope. When an ani- 

 mal is found that one desires to pre- 

 serve, a capillary tube is brought near 

 it, under the microscope, and as the 

 water runs up the tube it carries the 

 animal with it. It is blown out of 

 the tube into a drop of i per cent, 

 osmic acid solution, upon another 

 slide. After about ten minutes (at 

 the longest) it is stained with picro- 

 carmine, or with Beale's carmine, 

 washed wih water, and alcohol is 

 added, followed by oil of cloves. The 

 object can be transferred to another 

 slide by means of the capillary tube. 



Still simpler is the process for min- 

 ute, rapidly swimming protozoa. 

 When they are collected in a watch- 

 glass with a small quantity of water, 

 the necessary quantity of osmic acid 

 is added, then successively the color- 

 ing matter, alcohol, and oil of cloves; 

 all this is done in the watch-glass. 

 The animals remain so fixed in mu- 

 cous that seldom one is lost by draw- 

 ing off the fluids. 



Canada balsam is not so good for 

 many infusoria as glycerin; Actino- 

 sphcerium Eichornii is much better 

 shown in glycerin. The foamy ap- 

 pearance of the ectosarc is distinctly 

 revealed by this method of prepara- 

 tion, and the contractile vacuoles re- 

 main as in life. 



Will some of our readers try these 

 processes and send us a report of 

 their results ? Chromic acid can be 

 purchased of druggists, and if osmic 

 acid cannot be obtained, we will glad- 

 ly purchase it for any subscriber who 

 may desire it. 



* Zool. Anzeiger, 1883, No. I14. 



Impurities in Ice. — There is great 

 difference in people ! Some are most 

 excellent fishermen and others are 

 not. Now, we have no doubt that 

 Mr. Balen, who has furnished many 

 of our readers with microscopic or- 

 ganisms in great variety, is a good 

 fisherman in his way. But even he 

 must yield the palm to a medical gen- 

 tleman who has been catching the 

 microscopic animals and plants and 

 " morphological impurities " of ice. 

 We refer to Dr. Ephraim Cutter, of 

 New York, " Member Philosophical 

 Society, Great Britain, etc., etc.," who 

 has written upon this subject, and 

 whose article and illustrations speak 

 for themselves in the columns of the 

 Scientific Americati oi July 29th. In- 

 deed, Dr. Cutter has found the ice 

 so rich in microscopic organisms of 

 widely different kinds, that we most 

 unhesitatingly recommend our read- 

 ers whenever they want to make an 

 exhibition of microscopic life for 

 their friends to obtain a few pounds 

 of ice, melt it and put the sediment 

 under the microscope. 



The article in question begins with 

 a " Prelude," in which we are inform- 

 ed that the subject is " interesting 

 because ice is an article of commerce 

 and is extensively consumed." Some 

 of the hard words are explained, but 

 invariably it is stated that the "filtrate" 

 is examined microscopically, when in 

 fact it is not the filtrate at all but 

 the matter left in the filter that con- 

 tains the impurities — yet, we doubt 

 not, almost as much might be found 

 in the filtrate by an equally success- 

 ful observer. 



We will not attempt to name the 

 hundreds of things that contaminate 

 the ice — the only thing conspicuously 

 absent seems to be the " ague plant." 

 There are bacteria, which he suggests 

 may be the "babies (as it were) of 

 vegetation." The Astrionella is ac- 

 credited with a power of "self-sym- 

 metrical arrangement." As regards 

 " dirt," it is " hard to picture," and as 

 for many other things found in the ice, 

 the author is not sure they are hurt- 



