December 23, 1887.] 



SCIENCE. 



3ir 



To the best of my knowledge, all American makers provide 

 draw-tubes to their smaller instruments, by means of which they 

 may be contracted to as great an extent as any of the foreign ones, 

 and in my opinion the ten-inch tube is most decidedly not an un- 

 desirable feature. For a long time many of the best microscopists 

 of this country, as well as of Europe, have complained of the want 

 of unanimity among manufacturers in the construction of those 

 parts which are absolutely necessary in the microscope. Thus the 

 size of screw in objectives is probably definitely settled in favor of 

 the English standard, as this is almost universally accepted ; and 

 when not, it is by a few German and French makers. The length 

 of tube has for many years been the subject of agitation, and the 

 tendency is slowly but surely in favor of the ten-inch standard, and 

 by far the largest proportion of instruments are now constructed 

 accordingly. 



4. " The stage of the American microscope is very faulty." 



The stage of the American microscope does not differ materially 

 rom the majority of foreign ones. In almost all of the cheaper 

 forms it is " large and flat, with nothing upon it except a pair of 

 spring clips and a hole for a diaphragm." I am quite sure that it 

 is not only the amateur or fancy collector who uses the supple- 

 mentary glass stage ; and as to the mechanical stage, I think that 

 this originated in Europe, and is used even more there than in this 

 country. 



5. " Then the Iris diaphragm is often introduced to allure the in- 

 experienced, but it is not a good form except in conjunction with 

 an achromatic condenser." 



The apparatus is a European invention : it is widely used, and 

 highly valued by many persons. No doubt many would be pleased 

 to know what optical or mechanical reason exists, which prevents 

 it from being a good form. Besides this, the honesty of the Ameri- 

 can manufacturer will not permit him to stoop to any subterfuge 

 whatsoever to allure a purchaser; and the application of the Iris 

 diaphragm to an instrument can in no manner be construed to be 

 such, especially as the purchaser may select the diaphragm of his 

 preference. 



6. " There are other details of construction which are equally 

 open to unfavorable criticism, but it is unnecessary to go into their 

 discussion." If there are any other points, it seems but proper 

 that they should be stated. 



7. " The eye-pieces and objectives are generally, though not al- 

 ways, of a decidedly inferior character : when they are really good, 

 the lenses are* very expensive." 



This statement is a condemnation of American optical work, 

 which, with a knowledge of the literature on the subject, and ac- 

 quaintance of work which has been and is to-day produced, simply 

 cannot be made. Many of the important improvements have been 

 inaugurated by American opticians, and their work has been of a 

 high character, — a fact which is willingly conceded by a large 

 number of European microscopists who are fully qualified to judge. 

 That they have not retrograded is evinced by what they are doing 

 at the present day. Taken as a whole, I believe it can be safely 

 claimed that American objectives are of a higher grade, and more 

 uniform, than the European. More than this, the prices, compar- 

 ing quality for quality, are to-day fully as low as, and have been the 

 means of lowering, the prices of those which have been brought to 

 this country. The quality and prices of objectives, more than any 

 other part of the microscope, are less liable to conjecture and dif- 

 ference of opinion, from the fact that they can be determined by 

 actual comparison. 



8. " Many valuable members of the nation are sacrificed by being 

 obliged to pay for the advantage of a small number of men who 

 have never shown themselves willing to supply to those by whose 

 sacrifices they benefit, the kind of instruments wanted. ... Is it 

 unreasonable to ask manufacturers of microscopes in this country 

 to furnish us instruments of the kind we really need, as some sort 

 of acknowledgment of the money they extract from us whether 

 we will or not .'' " 



This complaint is not borne out by facts. As already stated, 

 there are, among all the manufacturers of microscopes, none more 

 progressive than the Americans. They have ever been ready to 

 accept suggestions and to make improvements when occasion to do 

 so presented itself. They are of sufficient business sagacity to 



undertake to make whatever may be called for, when there is a 

 prospect of a reasonable remuneration for the outlay. I hope I 

 may be excused in mentioning my personal experience in this con- 

 nection. 



Some years ago it came to the notice of the firm of which I am a 

 member, that there was at a certain quarter a decided opposition 

 to American instruments, and an influence exerted on students in 

 favor of certain foreign ones. 



To find the cause thereof, I made a special trip to Boston, and, 

 visiting a number of gentlemen, learned that the reason of their 

 preference was the pattern of the European instruments. Among 

 the gentlemen consulted was the writer of the article in Science. I 

 expressed a willingness to undertake to make an instrument which 

 should meet his views, and, after receiving a general outline of his. 

 preference, returned home and began to construct an instrument in 

 accordance therewith. 



After the completion of this, I made it the object of a second 

 visit. The instrument was thoroughly inspected and criticised, and 

 a number of minor changes recommended, which, upon my return 

 home, were strictly carried out. The instrument was again sent 

 for examination, April 23, 1884, accompanied by a letter, from 

 which the following extracts are made : — 



" As you will see, we have adopted the suggestions as made by 



you and Prof. , and believe that they add considerably to. 



the value of the instrument. . . . We send the instrument for ex- 

 amination, and hope you will make it severe ; for we are anxious to. 

 make just such an instrument, which you consider best suited to 

 students' use, and are convinced that we are able to do it." 



Later, in reply to an inquiry about his opinion of the Instrument, 

 we received the following : — 



" We have examined the Harvard microscope, and find it to be 

 very excellent in many respects, and the objectives good." 



(Signed) Charles S. Minot, 



During my visits I was kindly treated, received every reasonable 

 encouragement and the promise of support in the undertaking, and 

 was therefore the more surprised to read such charges. 



If European instruments are now happily gaining supremacy, it 

 must be of exceedingly recent date. Many scientists of this country 

 ' happily ' manifest great interest and pride in home productions ;. 

 and as the American manufacturers undoubtedly will endeavor to 

 combine in their instruments efficiency with high standard of work- 

 manship, as they are perfectly willing to make whatever may be re- 

 quired, and as they will ever welcome improvements by whomso-. 

 ever suggested, there seems no reasonable doubt that the ' suprem- 

 acy ' will be in future, as it is now, on the American side. 



Edward Bausch.. 



New York, Dec. 13. 



Dr. C. S. Minot, the able histologist of Harvard Medical School, 

 has, in a late number of this journal, given expression very freely 

 to his views in regard to the respective merits of microscopes of 

 foreign and domestic make. While the present writer cannot agree- 

 in detail with Dr. Minot's conclusions, many of the points made 

 against American instruments are, unfortunately, justified more or 

 less completely by the facts, and by the experience of teachers and 

 pupils in biological schools throughout the country, but similar 

 charges can be aimed with just as much truth and equal force 

 against many of the instruments which are imported from abroad 

 and commended as laboratory instruments. There are many of 

 them that I would absolutely not take as a gift if I could get the 

 best instruments of American make, and the best of those made 

 abroad are open to objections when considered merely as tools for 

 general biological work. A microscope is, or ought to be, an in- 

 strument of precision, and as such it is a tool which, according as 

 it is well or poorly made, will work satisfactorily or unsatisfactorily 

 in the hands of the skilled manipulator. I hold that nothing is too. 

 good as a tool for either pupil or teacher in biology. Histological 

 research and technique have reached that degree of development 

 and perfection within the past fifteen years, that the man who was. 

 a master in histology that long since, if he were to return to 

 the work in one of the many recently founded biological labora- 

 tories in the United States, would find that in cytology both, 



