Glass Byringe> For th« glass lyringf (fig* 6) & gl&st tub« i« 
employed as a plimg^r barrsl* This tube will hereafter be referred to 
as the glass tip or simply the tip* A brasi spring wire §9xy9 as a 
plunger, and • meohanioal peneil, as reooooaeaded by Solan {i), proridet 
the mechanism for Boring the plunger* The glass tip is attTohed to the 
end of the pencil housing^ and the plunger takes the plaoe of the lead* 
A number of special tools and materials are needed for a oonstruotion 
of this type* 
For drairing oapillary glass tubing an ordinary bunsen burner will do, 
but a blast burner is a great ooxxv^enienoe where both gfts and air are avtil* 
able* A gasoline blowtoroh has been found rery satisfaotory* 
A Jewelers* fine«grain glass^grinding wheel is needed for grinding 
off glass tips to the right diameter* Suoh a wheel oan easily be mounted 
on a shaft and made to turn slowly by means of a belt azid motor* ^e 
lower part of the wheel should dip into a tray of water to keep it flooded 
as it tvu*ns. The cooling action of the water prevents ohipping of the 
glass* 
A special gpis burner is needed for produoing a fine flame for use in 
forming the tapered end of the glass tips* This bvimer oan be a piece of 
e-^nuxit glass tubing drawn to an inside diameter of 0*5 mm* at one end* The 
burner is attached to flui ordinary gas outlet, which is adjusted to preduoe 
a flame about 5 mm* in diameter* 
A compound microscope equipped with a micrometer eyepiece and baring 
a magnification of about 60 diameters is useful in measuring the diameter 
of the glass tips as well as other small parts of the insemination equip* 
ment while under construction* Some of these measurements oan be made 
with an ordinary adorometer* If a compound microscope is not arailable^ 
a miorometer eyepiece oan be used in the dissecting microscope with a 
magnification of about 60 diameters* 
A number of small tools that oan be obtained fr(»i Jewelers* supply 
houses are needed* They include No* 6 cut files of various shapes, small 
flat-nose and pointed-nose pliers, and rods and triangular slips of fine- 
grain Arkansas stone* The end of a rod is ground on a coarser stone to 
a oone-shaped tip, -nhioh is used in grinding the inside edges of the 
oapillary tubing* These tools are also used in making the holding hooks 
and vaginal probe* 
A supply of No* 26 B, and S. gage wire should be on hand for making 
plungers. Several kinds of wire will do, but spring brass is preferred 
because it is stiff, yet solders well, and does not corrode easily* 
Some mechanical penoils are better adapted for syringe making than 
others. One having a round housing and using a 4-inoh load has been found 
most satisfaotory* This type (fig. 6) has a stationary, hollow metal core 
with a slot running its entire length* The lead and lead holder slide in 
this core, and a spiral made of steel wire or a steel strip encloses 
almost its entire length* Projections on the lead holder extend through 
the slot into the spiral, and as the spiral ic turned the holder slides, 
moving the lead in or out of the pencil* 
