1881.] 



MICROSCOPICAL JOURNAL. 



213 



We thus catch a glimpse of a possi- 

 ble function for an apparatus whose use 

 was before obscure. When directly 

 applied to the ganglion-cells, a mo- 

 mentary irritation can call out long- 

 continued action in the muscles. 



It is not impossible, though far from 

 being demonstrated, that their nor- 

 mal function is somewhat similar to 

 this. Perhaps when momentarily irri- 

 tated, in the normal manner, through 

 the sensory nerves, the ganglion-cells 

 may give origin to a long-continued 

 muscular contraction or series of con- 

 traction?. 



About Stands. 



[The following letter from Mr. 

 Stodder is given a place here,; in 

 large type, that no one may neglect to 

 read it. We have referred to it in 

 our editorial column. — Ed.] 



In your September number I find 

 an important paper on this subject. 

 So important do I find it that I ask 

 you, in all courtesy, the privilege of 

 saying a few words in controversion 

 of your dicta. *' There can be no doubt 

 that the time of the large and costly 

 microscopes is passed" * * * "but 

 the experienced worker, whether he 

 be an amateur or a professional man, 

 will surely discard them. Solidity 

 and steadiness can be secured with- 

 out excessive weight, and the smaller 

 and more compact a stand can be 

 made * * * the better it is. Now, 

 a stand that is sixteen or eighteen 

 inches high is very inconvenient to 

 work with. It is an undeniable fact, 

 which will be admitted by every in- 

 vestigator who has used both large 

 and small stands, that the latter are 

 by far the more convenient. There- 

 fore, we say that the best and most 

 salable stands of the future will be 

 the low stands, not much higher than 

 the common German model." 



I like to have one announce his 

 opinion distinctly, even if he does it 

 dogmatically, without arguments or 

 reasons. I ask for the privilege of 

 giving my dissent from such opinions 

 with reasons. 



Mr. Editor : Your journal has a 

 wide circulation among the young 

 and novices in science ; some of them 

 look to you for advice and your ar- 

 ticle about microscopes was evidently 

 written for the purpose of giving ad- 

 vice. I deem the advice you have 

 given as quoted above false, perni- 

 cious, and misleading. I controvert 

 each and every point that you give as 

 facts, viz. : There is a " doubt that 

 the time of large and costly micro- 

 scopes is passed." ** The experienced 

 worker will" not "surely discard them," 

 if he can get one. " Solidity and 

 steadiness can be secured without ex- 

 cessive weight ; " this is as indefinite 

 as a piece of chalk. Why not tell 

 your clients what you call excessive 

 weight — 6 lbs. or 30 lbs ? I claim, 

 from 25 years' use of the microscope, 

 that while 30 lbs. may be excessive, 

 16 lbs. is not ; that 4 lbs. is too light. 

 I believe that there is a general want 

 of information among beginners as to 

 the use of weight in a microscope. It 

 should be so heavy that every needed 

 movement can be effected with one 

 hand without touching the instrument 

 with the other, and not changing the 

 direction of the illuminating ray in 

 the slightest degree. It should be so 

 heavy that little slight accidental 

 touches, which will sometimes occur 

 to the most experienced worker, will 

 not only not upset the instrument, 

 but will not disturb its relation to the 

 light in the least. I have used stands, 

 of noted reputation, so light that the 

 most trifling touch or jar would move 

 them, and no movement of fine or 

 coarse adjustment, of the mirror or 

 draw-tube could be made unless one 

 hand held the instrument still, while 

 the other effected the movement ; 

 such instruments are unfit to use. 

 Avoid them. ** It is " not " an undeni- 

 able fact which will be admitted by 

 every investigator who has used both 

 large and small stands," etc. For it 

 is denied as emphatically as language 

 will permit. But directly the reverse 

 is the truth. It is the small, low Ger- 

 man stands that are inconvenient. It 



