1886.] 



MICEOSCOPICAL JOURNAL. 



195 



Mr. Long seems to doubt if the 

 crystals of butter are characteristic, 

 but if he relies upon ' A few experi- 

 ments ' to ' convince any one that he 

 [Dr. Taylor] is wrong on nearly 

 every point ' we must confess that it 

 seems scarcely fair that conclusions, 

 apparently so well established, should 

 be so easily overthrown. We are 

 inclined to believe that Dr. Taylor 

 can and does do all he claims, and, 

 so far as we know, no person who 

 has visited his laborator}- has as yet 

 detected an error in his observations, 

 and he has made many. It may be, 

 indeed, that Dr. Taylor has gone 

 rather too far in attempting to dis- 

 tinguish between different races of 

 cows by the form of the butter crys- 

 tal, but we are aware of instances in 

 which his inferences have been borne 

 out by the facts, however accidental 

 or incredible it mav seem. H. 



Measuring the Rate of Cili- 

 ary Motion. — An article recently 

 published in the Zeltschr.fur JMikr. 

 by M- Flesch, contains some refer- 

 ence to the application of strobo- 

 scopic observation in microscopy. 

 The author believes that it will find 

 many applications in the future. 

 Thus far, however, we are not aware 

 that it has led to any important dis- 

 coveries. Some time ago Mr. George 

 Hopkins constructed an instrument, 

 which was described in the Sclent ijic 

 Aniericaji^ and more recently Mr. 

 Chapman exhibited a similar appa- 

 ratus, devised by himself, at a meet- 

 ing of the Washington Microscopical 

 Society. We Avere not able to be 

 present at that meeting, and have not 

 since had an opportunity to see the 

 apparatus in operation, so it is with 

 regret that we have to refer to the 

 subject without practical knowledge. 



The essential feature of the device 

 is a moving diaphragm, which, bv 

 rapidly admitting and shutting out 

 the light, produces an intermittent 

 illumination, the speed being un- 

 der control of the observer. The 

 most convenient position for the 



diaphragm is probably beneath the 

 stage of the microscope. It is im- 

 portant that the speed should be per- 

 fectly under control. To use the 

 instrument, suppose it is desired to 

 know the speed of vibration of the 

 cilia of an infusorian, it is only 

 necessary to cause the diaphragm to 

 move at such a speed that the moving 

 ciHa will appear to be motionless. If 

 the speed is slower the cilia will seem 

 to move forward ; if faster the direc- 

 tion of the ciliary motion will seem 

 to be reversed. Having once found 

 the speed at which the motion seems 

 to cease, by increasing the speed 

 another rate will be found, fust double 

 the former, at which the cilia will 

 also appear stationary. 



Contrary to what might be antici- 

 pated, it is stated that no inconven- 

 ience is felt in observing with the 

 intermittent light, the interruptions 

 being so rapid that the eve fails to ob- 

 serve them. No doubt it will be pos- 

 sible to make this a valuable accessory 

 for research, and we would be glad to 

 hear of the experience of our readers 

 who may have the opportunit}' to test 

 it in practice. 



o 



Some Things Bacteria Do Not 

 Do. — There is a very strong disposi- 

 tion to attribute much more to the 

 action of microbes than the facts of 

 observation justify. LTnfortunately 

 we cannot appeal to common sense 

 to regulate such matters, for that 

 would not be a strictly scientific 

 method, but the most absurd and un- 

 reasonable statements will gain cir- 

 culation and credence, and if it be- 

 comes worth while to controvert 

 them at all it must be done at the 

 cost of much labor and time in lab- 

 oratory work. Not long ago some 

 person — very likely a person who 

 ought to have been more discreet 

 about putting forth such a notion, for 

 ^ve believe it did come from a person 

 of note, although we cannot recollect 

 the name — suggested or stated that 

 seeds would not genninate without 

 the presence of bacteria. As though 



