H.—3l

XXXVI

Examination of Water-samples. In all, forty-two samples of water were bacteriologically investigated. Owing to the larger part of my time'being taken up with the Wellington District office-work, I was unable to carry out the systematic examination of the water-supplies of all the principal towns, as it is impossible to do this in a satisfactory manner without visiting the place in person. The following supplies, however, were thus specially examined: — Wellington Industrial Farm, Levin, Wanganui, Burnham, ' Onehunga, Palmerston North, Hamilton Hospital, Auckland, Hamilton. A special visit was made to Hamilton to investigate the outbreaks of typhoid there, and many samples of water from various parts of the river above the intake of the borough supply were examined. Now that 1 have been relieved of the district work I shall be able to devote more time to this subject, Taking them generally, the public supplies in "the colony are mostly of good quality from the bacteriological standpoint. Vaccine Laboratory. The attached table summarises the work done during the year in connection with the manufacture and distribution of vaccine lymph.

Return of Vaccine Lymph issued for Year 1906.

Thirteen calves were vaccinated, and about 2,000 c.c. of glycerinated lymph prepared. Of this amount 8,420 tubes were issued to Public Vaccinators and medical men throughout the colony and 150 to the French Government at Tahiti. The recipients of lymph are somewhat lax in reporting their results, although a special report-form is issued with each parcel of lymph. Thus, of the 8,420 tubes issued we only received reports on 2,742. These returns show the proportion of successful vaccinations to have been 912 per cent., the insertion success being 849 per cent. This can only be classed as "fairly satisfactory," the results obtained by the English Ixxsal Government Board Laboratory being about 98 per cent, of case-successes; but there the lymph is withdrawn after two months. I have been withholding the lymph from use till it is absolutely free from all extraneous organisms, and, as, from various causes, largely climatic, this involves keeping it in a cool-store for sometimes as long as eight or nine weeks, a certain falling-off in the effective value results. Other causes of failure are at work which are more difficult to check, due largely to the treatment the lymph receives after it leaves our hands. It is impossible otherwise to account for failures by careful and competent vaccinators with a lymph which in other hands gives perhaps 100 per cent, of successes. It is probable that a lymph kept after glycerination for over two months becomes very sensitive to such influences as sunlight and heat, and very readily loses its potency. It is satisfactory to note that no cases have been reported where the reaction was unduly severe. Now that I have more leisure to attend to this branch of my work, I hope to be able to test aome of the modifications of the glycerination method, which may enable me to issue a germ-free lymph at an earlier period after manufacture.

Remarks. Number of Tubes issued. Primary. Eevaccination. Number of Scarifications to which Lymph was applied. Number of Vesicles obtained. Series. Cases done. Cases successful. 9 10 11 12 13 15 16 21 979 553 892 784 1,220 630 1,174 2,188 281 95 252 312 607 301 326 526 8 '2 3 4 8 8 7 7 722 268 612 1,018 1,969 912 959 1,416 582 210 552 907 1,736 838 761 1,102 289 97 255 316 615 304 333 533 253 81 246 294 579 295 291 462 8,420 2,700 42 7,876 6,688 (84-91%) 2,742 2,501 (91-21%)