TARTAR ON TEETH. 675 



very weak solution (1 in 1000) for the same period without change. I have 

 prepared solutions of curare in the following menstrua, viz., water, water 

 with 0.2iper cent, of salicylic acid, diluted spirit of wine (I to 3). The last 

 forms by far the best looking solution and is also the best solvent. It 

 'dissolves 85.2 per cent, of curare when left in contact with it for twenty- 

 ibur hours and filtered ; the dried residue hardly imparts any tinge to water. 

 Water dissolves 83 per cent, and diluted spirit 79 per cent, of curare, and 

 =the dried residue in each case gives a decided tinge to water; both solu- 

 tions are iridescent on the surface and at the side when examined in a glass 

 vessel, and commence to deposit soon after being filtered. The glycerine 

 ^solution deposits to a much smaller extent. 



It appears, however, from observations kindly communicated to me by 

 Dr. Ashburton Thompson, that even so weak a solution of glycerine as that 

 indicated above, viz,, 25 per cent, is productive of great pain when injected; 

 and seeing that the aqueous solution keeps very well, I would propose the 

 following formula as best meeting the requirements of the case : — 



HYPODERMIC INJECTION OF CURARE. 



Curare gr. j. 



Water.... min.xij. 



Dissolve ; let the solution stand forty-eight hours and filter. 



Using this solution two-thirds, a half, third, or quarter of a grain may be 

 given in a whole number of minims. Of the other strengths likely to sug- 

 gest themselves, viz., one in ten and one in fifteen, the first would only 

 ^llow of a tenth and a half a grain ; and the second, of a fifteenth, a third, 

 and two-thirds of a grain being given in the same way. The accounts of 

 the use of curare seem to indicate that the dose is from a quarter to a half 

 grain. 



Caution. — Curare requires to be handled with the utmost care. It should 

 not be allowed to come into contact with a fresh cut or a scratch. Two 

 good rules would be, never to powder it in dry condition and never to touch 

 it with naked fingers. — Druggists Circular. 



TARTAR ON TEETH. 

 BY A. H. TREGO, D. D. 8. 



Dentist are continually asked : " What is tartar, and why does it collect 

 on teeth ?" Practically, two words answer the two questions : "Indiges- 

 tion" and " carelessness." 



Commercially, tartar is an acid concrete salt, produced by fermentation 

 of wine, and is found incrusted on the inside of old wine casks. 



" Tartar" on teeth consists of salivary mucus, animal matter and phos- 

 phate of lime. ("Brown rust," "Caries" and erosions of the enamel are 

 quite different from tartar.) 



Tartar is^more prevalent in the mouths of " dyspeptics " and in those of 

 persons of " good constitution " who eat rapidly and leave the stomach to 



