178 PRoaREas of microscopical science. 



The ^American Naturalist ' on the dispute between Mr. Wenham and 

 Mr. Bichiell, wliicli was conducted in the pages of the ' Montlily Micro- 

 scopical Journal,' is somewhat severe on Mr. Wenham. The writer, who 

 signs himself C. S., and who is therefore easily recognized, says, that 

 for some three or four years some American microscopists have been 

 calling attention to the deception commonly practised by most work- 

 ing opticians in calling the " ' power of their instrument less than it 

 really is — i.e. calling an objective a quarter-inch when its focus is 

 really but one-fifth or one-sixth of an iucli, or an eighth when actually 

 one-ninth or one-tenth, — and some now apiu'oach to one-twelfth.' In 

 the ' Monthly Microscopical Journal ' for December, 1871, Mr. F. H. 

 Wenham writes a paper in reply to one of Mr. E. Bicknell's on this 

 subject, in which he takes Mr. Bicknell to task for exposing the decep- 

 tion, — and admits the truth of the charge. Here we have a gentleman, 

 well known throughout the microscopical world as one of the most ac- 

 complished theoretic opticians of London, generally supposed to be the 

 principal adviser of the working opticians, not apologizing for, but 

 practically defending the imposition, one that has been exposed and 

 complained of by Dr. Wm. B. Carpenter.' Mr. Wenham says ' a scien- 

 tific microscopist gives the diameters with his illustrations and the 

 nominal power of his object-glass ; this quite meets the case.' In this 

 Mr. Wenham is entirely ^vrong ; it does not meet the case. A power of 

 one thousand diameters obtained with a one-inch objective is a very 

 different thing from one thousand diameters obtained with a one-tenth, 

 unless the one-inch is ten times as good an instrument as the one-tenth. 

 The scientific microscopist should give with his illustrations, not only 

 the amplification he employed, but the real focus of the objective, and 

 the name of the maker, as astronomers do in the case of their tele- 

 scopic observations. He further says, ' In such a difficult and com- 

 plex arrangement as a high-power object-glass, it is almost impossible 

 for all the makers to work to the same magnifying standard.' That 

 of course depends on the knowledge of optics possessed by the work- 

 man, but has nothing to do with the matter. When the object-glass 

 is made, the focus can be measured, and the glass named accordingly. 

 The nearer the actual power comes to that intended, so much the 

 more credit to the maker ; the further it is from what he sells it for, 

 the more to his discredit. It is an axiom in microscopy that the 

 lower the power of a glass that will give a certain result or eftect, the 

 better the glass. Mr. Wenham's comparison with the steam-engine 

 is as inappropriate as Hartnack's objection to English microscoj^es, 

 that with their wheels and screws they look like a steam-engine." — 

 American Naturalist, February. 



TJie Muscular Fibres of the Small Bronchi. — On this subject Pro- 

 fessor Kindfleisch, in the ' Centralblatt ' of February 3rd, makes 

 the following remarks, which are tluis briefly abstracted by a con- 

 temporary : — 1. The smallest bronchi have a special and distinct 

 layer of transversely-disposed muscular fibres, which, in the places 

 where the former debouch into infundibula, are specialized into a 

 sphincter; they are cajjable of considerable dilatation, and have 

 under their epithelial layer a finely-meshed network of capillaries, 



