APPARATUS. 321 



have used them speak highly of them ; but for the pur- 

 poses of the practitioner, such instruments are not 

 strictly a necessity. The small German scales found in 

 the office of almost any physician can be made, with a 

 little attention, to do very fair work. If such be se- 

 lected, it will be of the very first importance to possess 

 a reliable set of weights ; those furnished with the cheap 

 instruments are not to be tolerated. Nor is it safe to 

 appeal to the nearest druggist. The safest method is 

 to make one's own, which is accomplished with no great 

 outlay of time or money. 



First, purchase a set of Troemner's " aluminum " 

 grain weights, costing fifty cents. These consist of a five, 

 four, two three's, two, one, and one-half grain weights. 

 With these in hand it will be easy to construct an accu- 

 rate set. Specific directions are unnecessary. 



A thousand grain bottle will also be wanted. This 

 can be purchased in the shape of a regular "specific 

 gravity bottle;" its cost is $2.00. The practitioner can 

 readily adapt an ordinary bottle to the purpose, simply 

 selecting one of such capacity that when a volume of 

 one thousand grains of rainwater at 60 F. is placed 

 therein, the water shall rise part way in the neck, and 

 its place marked with a file, we have on hand some half- 

 dozen 1,000 grain bottles, which we have picked up from 

 time to time, and which are in regular use, the specific 

 gravity bottle being held in reserve as a standard, or 

 for the determination at times of the density of liquids. 



Imprimis. Let me recommend to the practitioner that 

 he eschew the entire system of weights as recognized 



21 Microscopy. 



