116 



THE AMERICAN MONTHLY 



[June, 



of subscribers in this country. The 

 work will hereafter be supplied bound 

 in cloth, in three volumes, two of 

 text and one of plates. 



o 



— We have received so many con- 

 tributions for publication within the 

 last few weeks that some of them 

 must lie over for a month, and con- 

 tributors should not be disappointed 

 if their articles are not printed imme- 

 diately. To ensure early publication, 

 articles should be sent in as soon as 

 possible. In most cases articles are 

 used in the order of their receipt, but 

 this rule is not strictly adhered to, for 

 reasons that must be obvious to all 

 readers. 



Address of the President of 

 THE Royal Microscopical Socie- 

 ty. — We regret that we cannot print 

 this address in full, but there is so 

 much original, interesting matter now 

 in hand, that we have felt obliged to 

 curtail the address somewhat. As a 

 whole, it is one of the best, most 

 clear, sensible and intelligible presi- 

 dential addresses that it has been our 

 good fortune to read for some time. 

 o 



A New Medium for Mounting. 

 — The use of a solution of phospho- 

 rus in carbon disulphide was proposed 

 long ago by Mr. Stephenson, of Lon- 

 don, as a mounting medium for cer- 

 tain objects. The refractive index 

 of this solution is 2.1. It is a liquid 

 that requires considerable care in its 

 preparation and use, and is, therefore, 

 not likely to become very popular. 



Another solution, with a somewhat 

 lower refractive index, but one which 

 has the advantage of being readily 

 prepared, has been introduced by 

 Mr. Stephenson. It is a solution of 

 biniodide of mercury and iodide of 

 potassium in water. It may be used 

 of any strength, and the refractive in- 

 dex may be varied at will from 1.33, 

 which is the same as water, up to 

 1.68, which is greater than that of 

 monobromide of naphthaline. This 

 fluid gives the microscopist an aquous 



medium which can be used instead of 

 balsam or glycerin with equally good 

 results, so far as the visibility of 

 structures is concerned. 



Pond-life. — American microsco- 

 pists in general need to be urged to 

 devote more of their attention to 

 pond-life. It is lamentable that so 

 little is known of our microscopic 

 fauna and flora, while in England the 

 greatest interest seems to be felt in 

 the study of living microscopic organ- 

 isms. In the hope of stimulating our 

 readers to give more time to col- 

 lecting, we have printed several arti- 

 cles on collecting, describing what 

 was found on one or two occasions, 

 and once more we urge microscopists 

 who have not time to collect for 

 themselves, to order tubes regularly 

 from Mr. Balen. We can assure them 

 that they will get from him full value 

 for their money. He has sent delicate 

 living specimens across the continent 

 to California, which have reached 

 their destination in fine condition, 

 and, in case they do fail to survive the 

 journey he is always willing to send 

 another tube free of charge. We hope 

 he will he will be encouraged in his 

 work of collecting and distributing 

 specimens, by liberal orders from the 

 country at large. Those who wish to 

 see the beautiful Volvox globator in all 

 its beauty, would do well to send to 

 him for a supply. With the " Manual 

 of the Infusoria," by Mr. Kent, the 

 " Synopsis of Diatoms," by Dr. Van 

 Heurck, the " Fresh-Water Rhizo- 

 pods," by Prof. Leidy, or our own 

 " Synopsis of Rhizopods " with plates, 

 the collector would be well provided 

 with books of reference ; or with 

 either one of these he could confine 

 himself to a single subject, and study 

 it to advantage. There is still want- 

 ing a good work in English on the 

 algfe of fresh-water, and this we hope 

 will eventually be written by Mr. 

 Wolle. 



The Flagellates. — In the last 

 number of the Bulletin de la Sociite 



