1894 THE MICROSCOPE. 107 



12 per cent of the Mohammedans, 7 per cent of the Hindus and 

 5 per cent of the Pariahs use it. Each devotee on the average 

 consumes eight grains per day, four in the morning and four in 

 the evening. 



If used in moderation, it enables a person to do more work on 

 less food and sleep than otherwise. For the time being, it gives 

 him unusual cheerfulness and disposition to work, calms irrita- 

 tion, allays excitement, conquers resentment, quiets the nerves 

 and emotions, lengthens life, diminishes the death rate, cures 

 diabetes and never produces organic disease. Its chief evil is 

 producing constipation. Indian opium is pure and contains 

 but little morphine. Life Insurance Companies charge no extra 

 premium on the lives of opium eaters in India. 



QUESTIONS ANSWERED. 



NoTB.— ZJr. S. G. Shanks, of Albany, N. V., kindly consents to receive all sorts of ques- 

 tions relating to microscopy , whether asked by p> ofcssionals or amateurs. Persons of aU 

 g ades of experience , from the beginner upward, are welcome to the bentfts of this depur*- 

 ment. The questions are numbered for future reference. 



194. — What is a linen-'provei' f 



It is a small magnifier used for determining the fineness or 

 closeness of weaving in a linen fabric. 



195. — What is a Lucernal Microscope f 



It is a microscope in connection with which a lamp is em- 

 ployed as the source of illumination. 



196. — As a recreation for spare time, ivould a Swift or Crouch 

 Histological microscope with 1 inch and 1-6 inch objectives at $30, or 

 a Beckys " Star^^ Microscope ivith same objective, at S20, be the better f 

 Is a rack and pinion coarse adjustment any great advantage over a 

 sliding tube f — Juvenis. 



A Swift or Crouch Histological microscope should be pre- 

 ferred. A rack and pinion coarse adjustment is a great advan- 

 tage in inexpert hands, and a great convenience in any case. It 

 can be easily and precisely managed with one hand and there is 

 much less danger of forcing the objective against the object. A 

 sliding tube soon gets dirty and works stiffly, or it wears and 

 slides too easily. 



