86 



THE AMERICAN MONTHLY 



[February, 



mention some of the forthcoming an- 

 nouncements concerning the R. and 

 J, Beck optical goods, but before 

 long our readers will hear something 

 to their advantage. Mr. Walmsley 

 is agent for the Kingston photograph 

 plates, made in England, which are 

 to be highly recommended for micro- 

 scopical photography, as well as for 

 other purposes. 



At Mr. Zentmayer's we found an 

 article which should have a large sale. 

 It is an Abbe condenser, mounted so 

 that it can be fitted to almost any 

 stand with a sub-stage, with a con- 

 venient and ingenious fitting for the 

 diaphragms. This is undoubtedly 

 the most convenient form of the 

 Abbe condenser yet devised. It is 

 thoroughly practical, and only costs 

 $22.00. The new turn-table, de- 

 scribed last year, has been in good 

 demand, and the ' histological ' stand 

 is still as popular as ever. 



Mr. William Wales has been busy 

 enough, although trade is not very 

 brisk with any of the opticians. He 

 has lately made some half-inch ob- 

 jectives with an angular aperture of 

 50°, which have been highly spoken 

 of and with which he is well pleased 

 himself. One which he had on hand 

 was most excellent. We saw with 

 it some discoid diatoms, some muscu- 

 lar fibres and the podura-scale, but 

 Mr. Wales significantly remarked, 

 ' this lens will not resolve Pleuro- 

 sigma angulatum.'' 



Mr. Emmerich says that trade in 

 the objectives and apparatus of Zeiss 

 has been very good during the past 

 year, and he expects it to increase. 

 We have already alluded to some pre- 

 parations he offers for sale, but it 

 may be added that he will also have 

 some preparations of the tissues of 

 the young salamander, which are 

 prepared to show the various histo- 

 logical elements, elementary tissues, 

 cells, etc., making a valuable series 

 for study. 



Mr. Woolman had a good supply 

 of apparatus of difi'erent makers, and 

 as he is not devotin": his interests to 



any one make of goods, he is sure to 

 have something of interest at all times. 



Mr. J. Grunow is making some 

 fine objectives of the oil-immersion 

 type, which have been very highly 

 spoken of. He makes now a ^, a j"^ 

 and a J^ oil-immersion. A \ dry 

 which he has recently produced ap- 

 pears to be a very excellent objective 

 for general use. Its definition is 

 sharp with a ^-inch solid ocular, giv- 

 ing about 1300 diameters. The an- 

 gular aperture of this lens is 165° ; 

 the price is $40.00. Mr. Grunow 

 also makes an Abbe condenser, with 

 either two or three lenses, which is 

 very, well mounted. Some new 

 stands by Mr. Grunow are also excel- 

 lent in design and construction Mr. 

 Grunow's work seems to be better 

 known among medical men than 

 among the microscopists throughout 

 the country, but this is not due to its 

 want of merit, but rather to the fact 

 that his long-established business has 

 led his trade in a certain direction. 

 His improved camera lucida. Abbe 

 condenser, oil-immersion objectives 

 and well-designed stands, prove that 

 he is well able to meet the most ex- 

 acting demands of the time. 



One of the last places we visited 

 was the New York office of the 

 Bausch and Lomb Optical Companv. 

 For a notice of the various fine stands 

 and ingenious accessories they offer, 

 we cannot do better than refer the 

 reader to their well-illustrated cata- 

 logue We went especially to see the 

 electric light which they have applied 

 to the microscope. The result was in 

 every way satisfactory so far as the 

 general character of the light is con- 

 cerned. A very small lamp was 

 used and a brilliant illumination was 

 the result, far superior to lamp-light 

 of any kind, and more manageable. 

 The battery was objectionable. We 

 shall have something more to say 

 upon this subject next month, as our 

 space is now too fully occupied. 

 o 



Examination of Drikp Alg^e. — 

 It has long been known that by treat- 



