1890.] MICROSCOPICAL JOURNAL. lOn 



EDITORIAL. 



Meeting of the American Society. — Notice is sent out that if 50 

 members will get certificates that they have paid full fare going to De- 

 troit, it will he possible to secure return tickets at ^ regular fare. This 

 " if" implies doubt, and as a matter of fact in several past years there 

 have not been t^o such members. Additionally, reduced hotel rates 

 have been expected and not realized on some occasions. L^nless the 

 .Society can control these two features the attendance will suffer, and in- 

 deed it had better hold its meetings in conjunction with the American 

 Association for the Advancement of Science, which always does get 

 return rates and reduced hotel fares. 



W^alter H. Bulloch. — We are glad to announce the early removal 

 of anotiier friend to Washington. This time it is the accomplished 

 optician of Chicago, Mr. W. H. Bulloch, who comes here in order to 

 accept a position in the Coast Survey. If his friends each give him one 

 or two more orders at Chicago before the end of this month they will 

 probably receive attention and perhaps some fine l)ai"gains in view of 

 his closing business there. We shall be deliglited to have him in 

 Washington, and he may expect a cordial reception. 



BOYS' DEPARTMENT. 



Microscopical Examination of Starch. — The following para- 

 graphs embody all the essential parts of an enticing article by our friend 

 Dr. W. II. Sylvester, of Natick, Mass., in The Observer: 



Starch is composed of minute white granules or cells which difier 

 in size or shape in the different varieties of tuberous roots and plants. 

 vStarch may l)e detected by adding a small quantity of a solution of iodine 

 to a mixture suspected of containing it. All starch grains without ex- 

 ception turn lilue in the presence of iodine. Starch furnishes beautiful 

 objects for observation and study. It is one of the easiest things looked 

 at by beginners. The several varieties can be readilv obtained, and 

 there is not a cheap compound microscope that will not distinguish the 

 grains. 



Cut a bit of potato fine in cold water, let it stand half an hour, tlien 

 turn otrthe water, and in a short time a sediment will be thrown down, 

 which is the true potato starch. Place a drop of the sediment on a glass 

 slide, cover with thin glass and look at it with a power of one-fourth to 

 one-half inch. A much lower power will distinguish the grains. .Small 

 clam-shell-shaped bodies will be seen imder careful focussing marked 

 almost exactly like the surface of a clam shell, the most of the lines 

 seeming to radiate from a dark spot in the centre called the hilum. In 

 some kinds, as in arrowroot, the hilum looks verv much like a crack in 

 the centre, reminding one exactly of the crack in the centre of a potato 

 that has grown too rapidly. 



Ditlerent varieties of starch may be distinguished by measuring tiie 

 grains with a micrometer, although many cells of each should be meas- 

 ured and the average taken as the size varies. For example, manv of 

 the larger grains of arrowroot exceed in size the smaller grains of potato 

 starch, but tlie average size of the grains of potato starch is much larger 



