402 Medico-Legal 



solution of earth on the addition of serum ; (3) that this is due 

 principally to the presence of lime salts ; (4) that the lime can be got 

 rid of and the solution rendered clear, and not liable to clouding, by the 

 passage of CO2 and subsequent filtration ; (5) that the passage of CO2 

 in no way interferes with the reaction ; (6) that the quantity of lime 

 present in ordinary earth does not materially affect blood mixed 

 with it. 



EXPLANATION OF PLATE 



(Graham-Smith and Sanger). 



Fig. 1. No. 1 shows the precipitum with normal human serum (1 : 21 in salt solution) 

 and anti-human serum (•! c.c). No. 2 with putnd human serum (1 : 21) and antiserum, 

 and No. 3 with normal human serum (1 : 21) and putrid anti-human serum. No. 4 

 shows a clear solution of human serum in salt solution (1 : 21). No. 5 shows the 

 deposit resulting from the solution of human serum in distilled water (1 : 21). 

 No. 6 the precipitum formed with human serum diluted with distilled water (1 : 21) 

 and anti-human serum. Nos. 7, 8 and 9 show three capillary tubes such as are 

 used in quantitative measurements, and containing precipitum. 



Fig. 2 Shows effects of increasing quantities of NaCl on the formation of precipitum ; 

 each tube contains -5 c.c. of a 1 in 21 dilution of human serum, and -Ice. of 

 anti-human serum. No. 1 contains '6 70 of salt, and those following 1 7o' 2 7o) ^''/o 

 eo/o, 8%, 10%, 167o> 180/„, and No. 11 is saturated with salt. Results of 

 measurements are given on p. 103. 



Fig. 3 Shows the specific precipitum in tests for human blood dried for a month on 

 various materials. The lower series shows controls with anti-ox serum. The 

 cloudings in the tubes are due to the opalescence of the solutions ; and the various 

 solid particles are portions of undescended precipitum. 



No. 1 test for blood dried on silk handkerchief. No. 2 on tweed cloth. No. 3 on 

 black dress fabric, No. 4 on dark green cloth, No. 5 on coarse green cloth, No. 6 on 

 coarse red cloth, No. 7 on kid glove, No. 8 on blanket, No. 9 very coarse sack material, 

 No. 10 on flannel. Nos. 11 — 20 show control tests with anti-ox serum : all negative. 

 The solutions whenever necessary were neutralised before testing. 



Fig. 4. Nos. 1 to 5 show the effects on serum of dilutions of Hydrochloric acid in salt 

 solutions of strengths of 1 : 10, 1 : 100, 1 : 1000, 1 : 10,000 and 1 : 100,000. No. 1 has 

 a dense white cloud, No. 2 a slight cloud at the bottom. No. 3 a marked cloud, and 

 the others are unaffected. Photographed after 6 hours. 



Nos. 6 — 10 similarly illustrate the action of Tartaric acid. No. 1 (1 : 10) having 

 a slight cloud. No. 2 (1 : 100) a medium cloud. No. 3 (1 : 1000) a marked cloud, 

 Nos. 4 and 5 (1 : 10,000 and 1 : 100,000) are unaffected, the apparent deposit being 

 due to the light. 



Nos. 11 — 1.5 illustrate the action of Nitric acid. No. 1 (1 : 10) .shows the 

 coagulum, No. 2 (1 : 100) a very faint cloud. No. 3 (1 : 1000) a medium cloud, and 

 Nos. 4 and 5 are unaffected. 



Nos. 16—20 show the effects of Acetic acid. Nos. 1 and 2 (1 : 10 and 1 : 100) 

 have slight clouds, No. 3 (1 : 1000) a medium cloud, and No. 4 (1 : 10,000) a marked 

 cloud. No. 5 (1 : 100,000) is not affected. 



