o4 The Microscope. 



fail to do the subject justice. The price of the " Universal " is 

 somewhat less than that of the "Acme No. 3," still my choice 

 would be the "Acme," notwithstanding the fact that the mirror- 

 bar and the sub-stage arm are united in the tail'piece. Yet the 

 reader can not go far wrong in selecting either. 



Pressing closely upon both the " Universal " and the "Acme 

 No. 3 " comes Mr Bulloch's " Biological No. 2." It more than 

 presses them. It surpasses both. The Acme is the lowest of the 

 three in price and has a commendable length of body tube. In 

 other respects it is out of the race. The " Universal," in ad- 

 dition to its objectionable abundance of draw tubes, has spring 

 clips to " scalp off the cover glass," and is without means for the 

 application of the sub-stage Abbe condenser. The only really 

 objectionable feature about the " Biological No. 2 " is its divided 

 body tube. The stage is simple, convenient and rotating. The 

 sub-stage arm and the mirror bar are separate, the former being 

 movable by rack and pinion. It is adapted to the use of the 

 sub-stage condenser and other appliances, and the whole sub- 

 stage ring with all that it may carry, may be swung aside with- 

 out disturbing the mirror. The reader can hardly appreciate 

 this luxury unless he possesses it. I consider it one of the most 

 convenient and most desirable additions to any stand that any 

 optician has devised since the fine adjustment was transferred to 

 the back of the arm. This special sub-stage is again divided 

 into two movable parts, so that the lower ring may be swung 

 aside with the polarising prism, thus leaving the condenser and 

 the mirror undisturbed. These things are the most delightful 

 of luxuries, and no other stand of moderate price has these 

 beautiful appendages. The price is rather more than that of 

 either the " Universal " or of the "Acme No. 3," but the stand is 

 far superior to both. With it Mr Bulloch furnishes a Gillett or 

 a cone diaphragm. If the microscopist shall use the sub-stage 

 condenser these diaphragms will be useless. 



EDITOR'S, ^ 



^^DEPARTMENT 



ACORRESPONDNET calls my attention to the fact, that when 

 speaking in the December number of the streaming of pro 



